Lung transplantation: Procedure and postoperative management

INTRODUCTION — Lung transplantation has become an increasingly important mode of therapy for patients with a variety of end-stage lung diseases. Several types of transplant procedures are generally available including single and bilateral lung transplantation, cadaveric lobar transplantation, living-donor lobar lung transplantation, and heart-lung transplantation [1,2].

The procedures of single, bilateral, and living donor lobar lung transplantation and issues related to the early postoperative management will be reviewed here. The indications for each type of transplant, technique of heart-lung transplantation, donor lung preparation, and immunosuppression are discussed separately. (See "Lung transplantation: General guidelines for recipient selection" and "Lung transplantation: Deceased donor evaluation" and "Lung transplantation: Donor lung procurement and preservation" and "Lung transplantation: Anesthetic management" and "Heart-lung transplantation in adults" and "Induction immunosuppression following lung transplantation".)

PREPARATION — During the process of listing a patient with advanced lung disease for lung transplantation, the patient's indication for transplantation, disease-based preference for bilateral or single lung transplantation (BLT, SLT), comorbidities, surgical risk, blood type, and existence of donor specific antibodies are all reviewed. (See "Lung transplantation: An overview" and "Lung transplantation: General guidelines for recipient selection" and "Lung transplantation: Disease-based choice of procedure" and "Evaluation and treatment of antibody-mediated lung transplant rejection", section on 'Laboratory'.)

While the specifics vary among countries, the process of matching prospective donor lungs with recipients generally involves a centralized system that evaluates donor/recipient matches based on blood type, human leukocyte antigen (HLA) compatibility, size of the organ, and distance between the donor and recipient. Many matching algorithms prioritize recipients based on their severity of disease, and in the United States, this is reflected by the lung composite allocation score (CAS). Once the recipient is identified, the organ procurement organization helps coordinate logistics for a multi-organ donor and the transplant surgery is scheduled. (See "Lung transplantation: An overview".)

The recipient is prepared for surgery after matching with a donor lung, but induction of anesthesia is postponed until the donor lung has been fully examined and approved by the retrieval team. If the donor lung is satisfactory, the recipient operation can begin while the donor lung is in transit, although this is not universally true as the properties of the lung allow for prolonged cold storage. Details of preparation for anesthesia are provided separately. (See "Lung transplantation: Preanesthetic consultation and preparation".)

A standard checklist can help to ensure that all preoperative steps have been completed, including confirmation of side to be transplanted in SLT, blood type, HLA antibodies, and serologic status for cytomegalovirus (CMV) and Epstein-Barr virus (EBV) [3]. (See "Prevention of cytomegalovirus infection in lung transplant recipients", section on 'Pretransplant serologic testing' and "Treatment and prevention of post-transplant lymphoproliferative disorders", section on 'Prevention'.)

Potential lung transplant recipients will have been previously screened for pre-existing HLA antibodies to identify HLA epitopes that should be avoided in any potential donors for that recipient. Then, at most centers, a direct crossmatch is performed at the time of transplantation using fresh recipient serum and donor lymphocytes from peripheral blood or lymph node-derived cells. Given the relative urgency of transplant and accuracy of virtual crossmatch results, it is not typical to delay the operation until the direct crossmatch is completed at the recipient hospital. Thus, the results usually follow completion of the operation, and appropriate interventions can be taken if positive, such as plasmapheresis or augmented immunosuppression. (See "Evaluation and treatment of antibody-mediated lung transplant rejection", section on 'Laboratory'.)

As experience with lung preservation continues to evolve, we have gained a greater appreciation for the extended cold ischemic times that the lung can tolerate. Thus, it is possible to delay an operation until after the graft has arrived and rapidly complete the crossmatch with the lungs preserved. In addition, with the increasing utilization of the Organ Care System (OCS) device, ex-vivo lung perfusion facilitates transport to the implantation center, performance of crossmatch, and if suitable, transplant [4].

Steps to optimize lung preservation in transit from donor to recipient are described separately. (See "Lung transplantation: Donor lung procurement and preservation".)

OVERVIEW OF THE PROCEDURE — The procedure for lung transplantation is complex. The following is an overview for clinicians who are caring for lung transplant recipients, but is not intended to give specific instructions for the procedure. (See "Lung transplantation: Anesthetic management".)

Single lung transplantation — Single lung transplantation (SLT), which accounts for approximately 15 to 20 percent of adult lung transplantations (figure 1) [5], extends the limited supply of donor organs to more patients, but provides less lung function as a buffer for late complications and is not possible for patients with septic lung disease (eg, bronchiectasis, cystic fibrosis) or severe pulmonary hypertension. Long-term survival has generally been better after bilateral lung transplantation (BLT) than after SLT except for those with advanced age or medical comorbidities, such as patients over the age of 70 or with a history of prior chest surgery. In general, a right SLT is often preferable to a left SLT given that the right chest usually allows for a larger lung to be implanted and avoids manipulation of the heart, which can create hemodynamic instability intraoperatively. However, previous thoracic procedures or heterogeneity of the underlying disease may necessitate alternative laterality. The indications for SLT versus BLT are discussed separately. (See "Lung transplantation: Disease-based choice of procedure".)

The intended recipient is intubated with an endotracheal tube designed to facilitate one lung ventilation (OLV) during the procedure. Protective ventilation strategies are employed during OLV to minimize lung injury. (See "Lung transplantation: Anesthetic management", section on 'Induction and intubation' and "One lung ventilation: General principles" and "Lung isolation techniques".)

Standard posterolateral or anterolateral thoracotomy or a sternotomy incision can be used for SLT. An anterolateral thoracotomy may be preferable in that it provides enhanced exposure of the pulmonary hilum for the purposes of safe dissection. While ventilation is being delivered to the contralateral lung, the lung to be excised is deflated and mobilized. If persistent hypoxemia develops, the ipsilateral pulmonary artery is clamped to eliminate the shunt through the deflated, unventilated lung. Either refractory hypoxemia or hemodynamic instability at this stage would be an indication for extracorporeal mechanical circulatory support (eg, extracorporeal membrane oxygenation or cardiopulmonary bypass), which is always on standby. (See 'Extracorporeal life support' below.)

When the dominant lung is undergoing transplantation, mechanical circulatory support is generally required due to insufficiency of gas exchange via the remaining lung. For a right SLT, central cannulation is possible via the anterior thoracotomy or via cannulation by way of the femoral vessels. For a left SLT, cannulation options are more limited, and therefore access to the femoral vessels should be prepped into the operative field at the time of surgery.

While the dissection of the native lung is performed, the phrenic and vagus nerves must be safeguarded, and on the left side, the recurrent laryngeal nerve must be avoided as it courses under the aortic arch [3]. The pulmonary artery and pulmonary veins are sequentially ligated, after ensuring that the pulmonary artery pressure does not rise unacceptably in the remaining lung during tourniquet closure. If the PA pressure rise is excessive, mechanical circulatory support may be indicated for the remainder of the procedure. Identification of an unanticipated rise in pulmonary artery pressure at this time point is essential to avoid cardiovascular collapse secondary to right ventricular failure, hypoxemia, or hypercarbia during implantation, which has potentially catastrophic implications. Some centers utilize routine mechanical circulatory support regardless of elevated PA pressures or compromised gas exchange, and this is discussed in greater detail below. Regardless, close communication with anesthesia providers is essential and at many centers continuous transesophageal echocardiography (TEE) is used to assess the functional status of the right ventricle in real-time.  

Back table preparation of the lung graft is generally performed in sequence with removal of the native organ. Inspection for procurement injury is important as is interrogation of the pulmonary artery for residual thrombus. A pulmonary vein cuff that is deemed "too short" can generally be augmented with a piece of donor pericardium if it has been included with the graft or bovine pericardium if not [6]. The donor pulmonary artery should also be trimmed so that there is no redundancy at the level of the anastomosis once implanted, although this is often done in the recipient at the time of the anastomosis. The donor airway is generally trimmed as short as possible, with no more than one or two cartilaginous rings of the main bronchus retained. This minimizes watershed ischemia to the donor airway and reduces airway complications post-transplant.

If the right lung is being transplanted, the recipient right main bronchus is divided immediately proximal to the right upper lobe orifice. If the left lung is being transplanted, the left main bronchus is divided one to two cartilaginous rings proximal to the secondary carina. Division of the recipient airway, particularly the left side, should provide an adequate stump for anastomosis of the lung graft, but avoid an excess length that places the anastomosis in jeopardy of ischemia given the airway’s limited blood supply. The native lung is extracted and sent for culture and pathologic examination.

If the recipient hemithorax is limited in size, as is typically seen in recipients with restrictive lung disease, a retraction stitch on the diaphragm will improve visibility. The donor lung is implanted, and the three anastomoses are performed in their posterior-to-anterior anatomic sequence: bronchus, pulmonary artery, and pulmonary vein cuff to left atrium. A lung size mismatch is not uncommon between the donor and recipient structures and can require special technical adjustments when performing the anastomoses. (See "Lung transplantation: Donor lung procurement and preservation", section on 'Donor and recipient size matching'.)

Just prior to completing the final vascular anastomosis, air is vented from the pulmonary circulation and left atrium, and then ventilation and perfusion are restored to the graft. Reperfusion is initiated by removing the clamp on the pulmonary artery while venting the air and initial blood flow through a partially open pulmonary vein anastomosis. When de-airing has been deemed acceptable the clamp on the atrial side of the pulmonary vein anastomosis is removed and the sutures tightened. Recruitment and subsequent ventilation of the lung should not be performed until the newly reperfused lung has rewarmed fully.

An initial intravenous dose of 500 to 1000 mg of methylprednisone is administered intraoperatively prior to reperfusion of the allograft(s) or before transplant initiation. Our institution also administers a dose of mannitol to act as a free-radical scavenger and diuretic. Hypotension with cardiovascular instability can occur at this time point and close communication between the surgeon and anesthesiologist is necessary. Finally, controlled reperfusion of the allograft via partial occlusion of the pulmonary artery is favored as a method for reducing reperfusion injury when performing the transplant without mechanical support. When using cardiopulmonary bypass (CPB) or veno-arterial (VA)-extracorporeal membrane oxygenation (ECMO), reperfusion can be controlled with the extracorporeal device [7]. After completion of the anastomosis and hemostasis is achieved, chest tubes are placed in the pleural space and the chest is closed.

Bilateral lung transplantation — BLT is performed in 97 percent of pediatric lung transplant cases and approximately 80 percent of adult cases (figure 1) [8,9]. The specific indications for BLT are generalized bronchiectasis, such as in patients with cystic fibrosis; other chronic pulmonary infection; or severe pulmonary hypertension (PH) as detected on right heart catheterization. This last indication is somewhat center specific as SLT can be done in patients with mild to moderate PH. At our institution, we have generally used a mean PAP of great than 40 mmHg as a cutoff for severe pulmonary hypertension. This number is based on a review of the UNOS database which clearly demonstrated a reduction in survival in patients undergoing a SLT with mean PAP of greater than 40 mmHg [10]. Additionally, BLT is often performed in other lung transplant recipients to improve long-term outcomes [11]. (See "Lung transplantation: Disease-based choice of procedure".)

As with SLT, the procedure begins with anesthesia and intubation designed to facilitate one lung ventilation. (See "One lung ventilation: General principles" and "Lung isolation techniques".)

The standard approach, which we employ, is a bilateral sequential operation through a transverse thoracosternotomy (clamshell incision), typically through the fourth intercostal space. Incisions made too high or low can make exposure of the pulmonary hilum difficult, particularly when performing the venous anastomosis (figure 2) [3]. The lungs are implanted separately and sequentially [3]. The incision provides excellent exposure of the pleural space, which is imperative in cases of prior pleurodesis or dense adhesions.

Two alternative approaches to BLT are median sternotomy and bilateral anterior thoracotomies. Some surgeons still favor routine use of median sternotomy claiming less morbidity with this approach and less risk for infectious complications, but median sternotomy necessitates some form of mechanical circulatory support for optimal exposure, which requires heparinization and generally results in more transfusions. Several studies have associated CPB with increased rates of bleeding complications, transfusions, and primary graft dysfunction (PGD).

Regardless of approach, after the chest is opened, both native lungs are mobilized. If disease in the native lung is fairly homogenous in distribution, the right side is often performed first. However, if function is severely compromised on one side or the other, the native lung with the worst function (assessed preoperatively by perfusion scan or computed tomography [CT]) can be removed first, while one-lung ventilation is used on the contralateral lung. In general, extracorporeal circulatory support (ECLS) can be avoided by supporting the recipient with the contralateral lung if performing off-pump lung transplantation. Problems with hypoxemia or hemodynamic instability are managed in the same manner described for SLT. In addition, protection of the vagus, phrenic, and left recurrent laryngeal nerves and sequential division of the pulmonary artery, pulmonary veins, and main bronchus are the same described above for SLT. (See 'Single lung transplantation' above.)

Transplant teams have become increasingly liberal with the use of ECLS during lung transplant procedures. ECLS technology and approaches to cannulation have improved significantly over time. Options for support intraoperatively include veno-venous (VV)-ECMO, VA-ECMO, and full CPB. In some cases, VV-ECMO via bilateral groin access is all that is necessary for intraoperative support. In patients with pulmonary hypertension or a notable degree of RV dysfunction, support for the heart and lungs will be necessary with VA-ECMO or CPB. VA-ECMO does not require full heparinization, which has the advantage of reducing transfusion requirements. Our center has implemented a special "hybrid" circuit that allows for a quick conversion to full bypass without having to prime and exchange the VA-ECMO circuit for a bypass circuit [12]. Avoidance of full heparinization can be particularly important in the case of a hostile pleural space or mediastinum where extensive dissection is required. In certain situations, however, full CPB is unavoidable as complete decompression of the right ventricle is necessary. Whether ECLS positively or negatively impacts lung transplant outcomes is debatable and single center outcomes reports are conflicting. (See 'Extracorporeal life support' below.)

After the native lung is excised, implantation of the first allograft proceeds as for SLT (see 'Single lung transplantation' above). When the vascular anastomoses have been completed, air is purged from the pulmonary circulation and the left atrium, and ventilation and perfusion are restored to the graft. Deliberate, graded reperfusion of the new lung proceeds over 10 to 15 minutes. Some transplant surgeons advocate a brief interlude (30 to 45 minutes) to allow the allograft to acclimate prior to perfusing it with the full circulatory volume when proceeding with removal of the contralateral lung. In instances in which the transplant is performed on VA-ECMO, controlled perfusion to the first lung can be accomplished by adjusting ECMO flows to the pulmonary artery, as measured with a pulmonary artery catheter, and ensuring adequate end-tidal carbon dioxide (CO₂) when the newly implanted graft is ventilated.

One-lung ventilation is then switched to the allograft, and contralateral recipient pneumonectomy and donor lung implantation are performed. After completion of the anastomoses, chest tubes are placed in each pleural space and the chest is closed. The upper and lower portions of the chest wall are approximated with pericostal sutures and the sternum is secured with wires. Instability and displacement of the sternum requiring surgical intervention are rare. At this time, the double lumen endotracheal tube can be exchanged for a larger bore single lumen tube in order to perform thorough bronchoscopic examination and clearance of debris, blood, and mucous that might impair airway exchange. In addition, the integrity of the bronchial anastomoses is inspected to ensure that there is no evidence of lobar torsion (most commonly the lower lobe), which is a possibility in the absence of an intact inferior pulmonary ligament and a complete oblique fissure. After airway inspection and clearance, the recipient is transferred to an intensive care unit.

Living donor lobar transplantation — Lobar transplantation from living donors who are blood group and human leukocyte antigens (HLA)-donor specific antibody (DSA) compatible with the recipient has been performed for selected patients. In general, living lobar transplantation should be reserved for suitable candidates who, because of their clinical status, urgently need transplantation and, because of their place on the waiting list, seem unlikely to survive until a cadaveric donor becomes available [13]. Nevertheless, this practice is rare in North America and Europe and is mostly used in Japan where there is a critical scarcity of cadaveric donors.

The ethical issues surrounding transplantation from living donors have been reviewed [14-16], but the debate continues. Nonetheless, recipient outcomes have been satisfactory and donor morbidity has been minimal [13,16,17]. In a series of 369 live donors, 18 percent experienced a serious complication, 6 percent needed early rehospitalization, and 2 percent underwent reoperation [13]. While objective measures of lung function suggest low donor morbidity, two subjective complaints were common in a series of 15 lobar donors: a decrease in exercise tolerance and insufficient acknowledgement of the donation [16].

While the numbers are small, survival following living donor lobar (LDL) transplantation is similar to survival following cadaveric lung transplantation [17,18]. In a review of lung transplantation in Japan, the five-year survival was comparable between 181 LDL recipients and 283 cadaveric recipients (71.6 and 72.3 percent, respectively) [18].

When performing LDL, careful size matching is needed, and sometimes it is necessary to downsize the graft to achieve a good fit [18,19]. Preoperative three-dimensional CT may help plan downsizing of donor lobes or use of a single lobe with contralateral pneumonectomy [18,20]. The technique for LDL transplantation is similar to that described for single and bilateral lung transplantation above. At the time of surgery, if the lobes are obtained from two donors, three surgical teams are required (one for each donor and one for the recipient). The ischemic time for the allograft is substantially less due to the ability to initiate recipient surgery during lobe retrieval from the donor and implant the allograft immediately upon retrieval.

One ongoing concern is that implanting lobes from two different donors makes HLA matching more complicated [18]. On the other hand, it is possible that LDL recipients will experience less chronic lung allograft dysfunction (CLAD) as it may only affect one of the allografts [21].

Cadaveric lobar transplants — Cadaveric lobar transplants (CLT) can be a useful strategy to transplant rapidly deteriorating candidates on the wait list. It is most appropriate for the use in pediatric patients and small adults with pulmonary fibrosis or cystic fibrosis. The largest experience in this area has been published by the Vienna group [22].

Heart-lung transplantation — Heart-lung transplantation is discussed separately. (See "Heart-lung transplantation in adults".)

EXTRACORPOREAL LIFE SUPPORT — Extracorporeal life support (ECLS), either cardiopulmonary bypass (CPB) or extracorporeal membrane oxygenation (ECMO), is an increasingly common adjunct utilized during lung transplant procedures [23,24]. Likewise, it is a common trend to use VA-ECMO for intraoperative cardiopulmonary support in lung transplantation rather than conventional CPB. (See "Extracorporeal life support in adults in the intensive care unit: Overview".)

Indications — The use of ECLS during lung transplant ranges from routine use at some centers to selective use at others. For instance, in one report of 170 patients who required ECMO support for lung transplantation, approximately 44 percent had an unanticipated need that developed intraoperatively and 56 percent were determined preoperatively to require ECMO [25]. It is difficult to assess the overall impact of ECLS given that its unanticipated use denotes a complicated operation beset by unforeseen difficulties, whereas planned use is more generally indicative of proper preoperative planning in a complex patient. As the popularity of routine use of VA-ECMO in lung transplant continues to rise, we will be able to better assess its impact.

One retrospective study from a center using routine VA-ECMO intraoperative support compared the use of planned VA-ECMO (69 patients) with historical planned off-pump transplants (169 patients) in those without moderate or severe pulmonary hypertension [26]. Compared with the off-pump group, patients receiving planned VA-ECMO developed less acute rejection (1.5 versus 11 percent) and a trend toward a lower rate of grade 3 PGD at 72 hours (12 versus 17 percent). However, there was also increased use of postoperative VV-ECMO (21 versus 12 percent), more surgical re-exploration (29 versus 16 percent), and a trend towards higher 90-day mortality (5.9 versus 1.2 percent). Increased numbers of retransplants in the VA-ECMO cohort (13 versus 5 percent) may have biased outcomes in favor of the off-pump group.

Preoperatively anticipated indications for ECMO include patients already requiring ECMO and those with idiopathic pulmonary artery hypertension, other Group 1 pulmonary vascular diseases (table 1), or other indications (eg, pulmonary fibrosis, cystic fibrosis or chronic obstructive pulmonary disease [COPD]) with known severe secondary pulmonary hypertension, severe hypoxemia, or significant hypercapnia. Preoperative risk factors for unanticipated need for ECMO include pulmonary fibrosis [27], secondary pulmonary hypertension (Group 3), and a dilated or hypertrophied right ventricle without preserved cardiac output. Patients on mechanical ventilation prior to transplant are more likely to need extracorporeal support.

Unstable hemodynamics or refractory hypoxemia necessitating CPB or ECMO most often arise at one of three points in the operation:

●After clamping the pulmonary artery during the first transplant

●After perfusing the first allograft but before starting the second lung

●After clamping the pulmonary artery during the second transplant

The frequency of intraoperative conversion to CPB or ECMO, compared to procedures without extracorporeal support or with elective support, varies among institutions [25,27,28]. Among 302 lung transplant recipients at a single center, 54 (18 percent) required intraoperative conversion to CPB, 162 (54 percent) had elective CPB, and 86 (28 percent) were managed without CPB [28]. In a separate series of 595 lung transplant recipients, 75 (13 percent) required intraoperative conversion to ECMO, 95 (16 percent) had elective ECMO, and 425 (71 percent) were managed without intraoperative cardiopulmonary support [25].

Choice of modality — CPB was the standard method for patients who required hemodynamic support during lung transplantation procedures for many years. However, CPB requires full heparinization, which increases the risk of perioperative bleeding and transfusion needs. An alternative is to use veno-arterial (VA)-ECMO requiring much lower systemic anticoagulation levels [29,30]. We favor the use of VA-ECMO, in place of CPB, as a growing body of observational evidence suggests that ECMO may be preferable to CPB [23,31-34]. While results vary among studies, among 271 patients requiring CPB or ECMO for lung transplantation, the occurrence of severe primary graft dysfunction (PGD), need for red cell transfusions, and the 30 day and 6-month survivals were not different between the groups [31]. However, CPB was associated with higher rates of reintubation and renal failure necessitating dialysis.

When choosing between ECMO and CPB, the needs of the individual patient and situation should guide decision-making. For example, in patients with severe right heart dysfunction, full decompression of the heart, which can be best accomplished via CPB, may be preferable. Alternatively, in patients who are anticipated to have dense pulmonary adhesions and/or mediastinal adenopathy (ie, cystic fibrosis) where diffuse bleeding will only be accentuated by systemic heparinization, attempts to either complete the transplant off support or with ECMO (which require less or no heparinization) may be preferable. Finally, the successful application of this technology requires thoughtful interpretation of preoperative patient variables and strong intraoperative planning and communication. (See "Lung transplantation: Anesthetic management", section on 'Mechanical cardiorespiratory support'.)

Transplant centers are increasingly using VV-ECMO to bridge patients to lung transplant. In this situation, we typically convert these patients to VA-ECMO for the duration of the procedure. In certain instances, patients are being maintained on a dual lumen bicaval cannula. In these cases, we will maintain two competing circuits, running the bicaval cannula at a flow of 1.5 L while also cannulating centrally for VA-ECMO support. At the end of the case, we will then decannulate centrally and recover the patient briefly via the bicaval cannula in the ICU.

ANASTOMOTIC CONSIDERATIONS

Pulmonary vein anastomosis — Pulmonary venous complications are rare but can be a major cause of morbidity and mortality if not identified and treated promptly [35]. It is common practice to have the anesthesiologist interrogate the pulmonary vein anastomoses by transesophageal echocardiogram (TEE) at the conclusion of the implantation prior to chest closure. TEE enables a calculation of size and velocity across the anastomoses. Accepted values include diameters of greater than 0.5 cm with peak systolic velocity ≤1 m/sec at the anastomoses [35], but a systematic review demonstrates the lack of true consensus on what constitutes concerning velocities. For example, the authors’ conclusion is that a peak pulmonary cuff velocity of 1.59 m/sec constitutes cause for concern, but that is with a confidence interval of 0.66 m/sec [6,10]. TEE is preferred over direct visualization, as the latter is less sensitive. However, direct pressure measurements allow for another method of measuring a pressure gradient across the PV anastomosis. Importantly, intraoperative identification of anastomotic narrowing enables immediate revision. (See "Noninfectious complications following lung transplantation", section on 'Pulmonary cuff dysfunction'.)

In rare cases, pulmonary vein anastomotic complications are detected post-transplant. In the immediate postoperative period, complications are generally technical in nature although thrombosis can occur. Clinical manifestations include hypoxemia, persistent pulmonary edema, high pulmonary capillary wedge pressures, and radiologic evidence of consolidation. Delayed perioperative stroke, particularly when embolic in appearance on brain imaging, is a clue to the possibility of thrombus in the pulmonary vein or left atrium. However, perioperative stroke is more commonly due to air embolism or aortic cannulation manipulation. Suspicion of a pulmonary vein anastomotic complication whether discovered intraoperatively or postoperatively requires immediate intervention.

Pulmonary artery anastomosis — Technical complications related to the pulmonary artery (PA) anastomosis can be due to stitches that are placed to staunch bleeding, PA torsion, or when the donor PA is not trimmed appropriately and the artery is redundant. Intraoperative assessment of the pulmonary arteries using TEE is generally more difficult than visualization of the pulmonary veins and, at our center, not routinely performed [36]. However, when PA anastomotic problems are suspected due to hypoxemia or PA hypertension, prompt evaluation is indicated. One preferred method is direct pressure measurements pre- and post- anastomosis evaluating for a significant gradient. Of course, it is ideal to make these determinations intraoperatively but many times they are discovered postoperatively. As with the pulmonary vein anastomosis, PA complications are rare but should be suspected in cases of hypoxemia and pulmonary hypertension, but without evidence of pulmonary edema. Contrast CT scan protocoled for cardiac evaluation has become our preferred method postoperatively for interrogating PA and pulmonary vein (PV) anastomoses when renal function is not a concern. Again, immediate intervention is necessary to salvage the graft.

Bronchial anastomosis — The bronchial anastomosis is a particularly vulnerable site for complications especially later after transplant, as the normal bronchial blood supply to the donor airway is disrupted during transplantation, so the donor bronchus is dependent upon retrograde bronchial blood flow through the pulmonary circulation, unless direct bronchial revascularization is performed. Using current techniques, most centers report rates of airway anastomotic complications in the range of 3 to 18 percent. A discussion of airway complications after lung transplantation is provided separately. (See "Airway complications after lung transplantation".)

The preferred bronchial anastomotic technique has evolved over time and is currently an end-to-end anastomosis without omental wrap or bronchial artery revascularization [37,38]. The donor bronchus is transected no more than one or two cartilaginous rings above the lobar carina to reduce bronchial ischemia [37]. The membranous portions of the donor and recipient bronchi are typically approximated and anastomosed using a running suture, while the cartilaginous layers are anastomosed with interrupted sutures [3]. Alternatively, our center prefers the use of a single running technique with an absorbable suture that creates an end-to end anastomosis for the membranous portion, but partially telescopes the cartilaginous portion of the airway.

Techniques that are no longer or rarely used include an end-to-end bronchial anastomosis with an omental wrap (omentopexy) and end-to-end anastomosis with bronchial artery revascularization, using microsurgical techniques. While revascularization has theoretical appeal, its benefits are uncertain, and it has not been widely employed [39-41]. (See "Airway complications after lung transplantation", section on 'Specific complications'.)

POSTOPERATIVE MANAGEMENT — Early postoperative care focuses on ventilatory support and weaning, fluid and hemodynamic management, immunosuppression, detection of early rejection, and prevention or treatment of infection. As the patient recuperates, the emphasis shifts toward regulating the medical regimen, establishing the routine for postoperative monitoring, and continuing rehabilitation and education. This section provides an overview of post-transplantation care, while details about rejection, immunosuppressive regimens, prophylaxis and treatment of infections, and other complications are covered separately. (See "Induction immunosuppression following lung transplantation" and "Infection in the solid organ transplant recipient".)

Ventilatory support and weaning — The ventilation and weaning techniques after lung transplantation are dependent on the underlying lung disease and whether a native (diseased) lung is still present.

Given the success of "lung protective" ventilation in adults with acute respiratory distress syndrome, this strategy is also utilized for lung transplant recipients in hopes of reducing primary graft dysfunction (PGD) and ventilation-induced lung injury. While experience is limited in lung transplantation, a "lung protective strategy" is advised with a low tidal volume (≤6 mL/kg based on donor predicted body weight) and maintaining plateau pressures ≤30 cm H₂O [42]. The respiratory rate is adjusted to maintain the minute ventilation. (See "Acute respiratory distress syndrome: Ventilator management strategies for adults", section on 'Low tidal volume ventilation: Initial settings'.)

After single lung transplantation (SLT) for chronic obstructive pulmonary disease (COPD), positive end-expiratory pressure (PEEP) is not used or is limited to low pressures (eg, 5 cm H₂O), because PEEP may overinflate the more compliant native lung. Ensuring adequate expiratory time to allow complete exhalation by the native lung can also help to prevent dynamic hyperventilation. (See "Invasive mechanical ventilation in acute respiratory failure complicating chronic obstructive pulmonary disease".)

After SLT for other indications or bilateral lung transplantation (BLT), an appropriate level of PEEP (eg, 5 to 10 cm H₂O) is a standard part of postoperative ventilatory support. (See "Lung transplantation: Anesthetic management", section on 'Ventilation after lung transplantation'.)

For patients with postoperative hypoxemia, the differential diagnosis is broad and includes all the processes known to cause postoperative hypoxemia (eg, fluid overload, heart failure, atelectasis, pneumonia, pleural effusion, venous thromboembolism, bronchoconstriction), as well as factors related to lung transplantation, such as PGD (most common cause of hypoxemia post transplantation), pneumothorax, anastomotic issues, and pericardial tamponade.

In many instances, hypoxemia and hypercapnia can be overcome with aggressive bronchoscopic removal of debris and secretions, which can occlude the distal airways and interfere with gas exchange. If the findings on bronchoscopy do not explain and improve the poor gas exchange, a reasonable next step is computed tomography (CT) with contrast protocoled to visualize pulmonary vessels or a perfusion scan to look for defects in perfusion due to thrombus or anastomotic narrowing. The majority of the time, early challenges with gas exchange are due to PGD or atelectasis and not due to technical complications. Therefore, the CT with contrast can provide detailed anatomic evaluation of the anastomoses and parenchyma, but the benefit of contrast enhancement needs to be weighed carefully with the nephrotoxic risks. A non-contrast CT scan augmented with transesophageal echocardiogram (TEE) interrogation of the pulmonary veins (PVs), and perfusion scanning can provide important information when intravenous contrast is contraindicated. A discussion of the management of PGD is provided separately. (See "Overview of the management of postoperative pulmonary complications" and "Primary lung graft dysfunction".)

In the majority of patients without ventilatory difficulty after transplant, weaning can usually proceed quickly during the first few hours to days. We typically perform a bronchoscopy prior to extubation, which will clear residual blood and debris from the distal airways and help insure successful extubation. However, patients who experience severe PGD or require VA- or VV-ECMO support for other reasons, may need ventilator support until ECMO is successfully discontinued.

For patients who are not progressing appropriately, early tracheostomy can be advantageous. It facilitates patient comfort, weaning sedation, withdrawing ventilator support, and managing pulmonary toilet, without adding significant morbidity.

Fluid management — Maintenance of adequate filling pressures and cardiac output must be balanced with the desire to minimize pulmonary edema, and individualized management is needed to achieve the right balance. Some degree of pulmonary edema of the newly transplanted lung is almost universal because vascular permeability is increased and lymphatic drainage has been disrupted [43,44]. This is often termed "reperfusion injury" although in lung transplantation it is referred to as PGD. To minimize pulmonary edema, pulmonary capillary wedge pressure is kept as low as possible (eg, 5 to 15 mmHg), consistent with adequate urine output, oxygen delivery, and systemic blood pressure [45]. Conversely, some volume resuscitation is unavoidable and is preferable to excess escalation of inotropes and vasopressors, the combination of which can contribute to end-organ damage (ie, acute renal insufficiency). If large volume resuscitation is anticipated after a lengthy and complicated lung transplant (ie, redo transplant), support of the new graft may be aided by short-term VV-ECMO if oxygenation or pulmonary compliance are inadequate. (See "Overview of postoperative fluid therapy in adults".)

The optimal fluid for volume replacement post-transplant is unknown, and the approach to this situation varies among institutions. In general, we attempt to avoid transfusions and resuscitate with crystalloid solutions such as Lactated Ringer. It is important to keep in mind that immediately post-transplant, patients tend to be acidotic with significant base deficits due to washout and reperfusion of the new lungs. Crystalloid remains the most cost-effective and initial fluid of choice for resuscitation. In addition to added cost, many colloids such as hetastarch have been found to be deleterious on renal or pulmonary function and are generally avoided. However, if significant resuscitation fluid is needed (ie, >2 L) then we will often use albumin sparingly. Although no clear threshold has been established in lung transplantation, we generally transfuse in the early postoperative period for a hemoglobin of 7 to 8 g/dL. (See "Overview of postoperative fluid therapy in adults", section on 'Replacement fluids'.)

Typical postoperative sequelae (eg, intravascular volume depletion, blood loss, acute myocardial injury, infection, auto-PEEP) can contribute to postoperative hypotension and may need directed assessment and intervention beyond fluid management. Sometimes this can be complicated. For example, in the question of myocardial infarction, electrocardiogram (ECG) changes associated with pericarditis such as ST segment elevation are very common, and mild increases in troponin post-transplant are universal. Therefore, a high index of suspicion and other methods of assessment, such as pulmonary artery catheter and TEE monitoring can be helpful adjuncts.

Management of primary graft dysfunction — PGD represents a multifactorial injury to the transplanted lung that typically develops in the first 72 hours after transplantation. Ischemia-reperfusion injury is thought to be a major cause. Moderate to severe PGD is associated with impaired oxygenation, decreased lung compliance, elevated pulmonary arterial pressures, and pulmonary opacities on chest radiograph. The diagnosis, grading, and management of PGD are discussed separately. (See "Primary lung graft dysfunction".)

For patients failing to maintain adequate oxygenation (eg, partial pressure of arterial oxygen [PaO₂]/fraction of inspired oxygen [FiO₂] [P/F ratio] <100 mmHg) or clearance of carbon dioxide despite optimization of supportive care and administration of inhaled nitric oxide (iNO) or nebulized epoprostenol, ECMO can be used to bridge patients to recovery. In general, VV-ECMO is sufficient for support of the allograft in this setting, and we implement its use when the required FiO₂ exceeds 60 percent or the peak airway pressures exceed 32 cm H₂O. The use of ECMO in treating PGD is discussed separately. (See "Primary lung graft dysfunction", section on 'Treatment'.)

Chest tube management — Chest tubes are kept in place typically until drainage amounts are less than 300 mL/24 hours with absence of air leak. Most patients will have all chest tubes removed within 7 to 10 days after transplantation. (See "Thoracostomy tubes and catheters: Indications and tube selection in adults and children" and "Pleural complications in lung transplantation", section on 'Pleural complications following lung transplantation'.)

Initiation of immunosuppression — All patients undergoing lung transplantation need immunosuppressive therapy to try to prevent allograft rejection. At our institution, we commonly administer tacrolimus in the preoperative holding area when the donor is deemed acceptable; basiliximab for induction and mycophenolate mofetil are given intraoperatively. As noted above, a bolus of methylprednisolone (usually 500 to 1000 mg) is given intraoperatively before perfusion of the graft. (See "Induction immunosuppression following lung transplantation" and 'Overview of the procedure' above.)

Maintenance immunosuppression is begun promptly after surgery and typically consists of three drugs: a glucocorticoid, a calcineurin inhibitor (cyclosporine, tacrolimus), and a nucleotide blocking agent (azathioprine, mycophenolate mofetil). Maintenance immunosuppression is discussed separately. (See "Maintenance immunosuppression following lung transplantation".)

Infection prophylaxis — Infection has been one of the leading causes of early morbidity and mortality. In the perioperative period, bacterial pathogens are the greatest threat, but fungal infection with Candida or Aspergillus species or viral infection with herpes or cytomegalovirus (CMV) can also arise. (See "Prophylaxis of infections in solid organ transplantation".)

Prophylaxis against bacterial, fungal, and viral infection is routinely administered perioperatively. In the absence of specific culture results, most centers use an initial empiric regimen. The regimen should be expanded to include coverage of potential pathogens that have been isolated from the donor or recipient, as well as local infectious considerations. (See "Bacterial infections following lung transplantation" and "Fungal infections following lung transplantation" and "Prevention of cytomegalovirus infection in lung transplant recipients" and "Viral infections following lung transplantation".)

Fungal prophylaxis varies among transplant centers. At our institution, we usually continue fluconazole for 90 days after transplant to reduce the risk of invasive candidiasis, while inhaled liposomal amphotericin is used during the hospitalization to target airway mold colonization. Nystatin swish and swallow is also given to prevent oral candidiasis for approximately six months.

Sulfamethoxazole/trimethoprim is the first line agent against Pneumocystis jirovecii; inhaled pentamidine, dapsone, or atovaquone can be used as second-line agents.

Practices regarding prophylaxis against CMV vary significantly among transplant centers as well. At our institution, CMV prophylaxis is given to all CMV positive recipients early after transplant. However, the total duration of prophylaxis is dictated by the donor CMV status. The only recipients not to receive CMV prophylaxis are those that are CMV negative pretransplant and receive a CMV negative donor. We administer prophylaxis against CMV initially with ganciclovir, followed by transition to valganciclovir or acyclovir depending on recipient and donor CMV IgG status.  

Chronic immunosuppression in the weeks to months after lung transplant places recipients at an ongoing increased risk for opportunistic infection. Prophylaxis for these infections is discussed separately. (See "Prophylaxis of infections in solid organ transplantation" and "Prevention of cytomegalovirus infection in lung transplant recipients".)

Prevention and treatment of venous thromboembolism — Lung transplant recipients are at moderate risk for postoperative venous thromboembolism (VTE; which includes deep vein thrombosis [DVT] and pulmonary embolism), particularly in association with older age, prior VTE, prolonged mechanical ventilation, and use of extracorporeal life support. In the majority of patients, low dose subcutaneous unfractionated heparin is used for prophylaxis, although a more intensive regimen may be prudent in patients with a past history of VTE. VTE prophylaxis is typically continued until hospital discharge. (See "Prevention of venous thromboembolic disease in adult nonorthopedic surgical patients" and "Noninfectious complications following lung transplantation", section on 'Venous thromboembolism'.)

Even with the use of prophylaxis, DVT is not uncommon postoperatively in lung transplant recipients, and patients should be accordingly anticoagulated when clinically indicated. We typically utilize heparin in these situations with a transition to warfarin or one of the direct oral anticoagulants (DOACS). Although a myriad of new agents is available, the capacity to monitor their degree of anticoagulation routinely and inexpensively is limited. In addition, the reversal of their effects is difficult, thus our continued reliance on heparin and warfarin. (See "Noninfectious complications following lung transplantation", section on 'Venous thromboembolism' and "Overview of the treatment of proximal and distal lower extremity deep vein thrombosis (DVT)" and "Direct oral anticoagulants (DOACs) and parenteral direct-acting anticoagulants: Dosing and adverse effects".)

Nutritional support and stress ulcer prophylaxis — Nutritional support and stress ulcer prophylaxis have not been specifically studied in lung transplantation and follow usual postoperative practices. (See "Overview of perioperative nutrition support" and "Stress ulcers in the intensive care unit: Diagnosis, management, and prevention".)

Many post lung transplant patients suffer from esophageal and gastric dysmotility. These problems are sometimes present pretransplant, or are a byproduct of intraoperative vagal nerve injury and medication adverse effects. Recurrent laryngeal nerve injury can also occur during transplantation. Speech therapy evaluation prior to the initiation of an oral diet is important to rule out aspiration. In cases of aspiration or profound esophageal/gastric dysmotility enteric feeding access may be preferred. (See "Physiologic changes following lung transplantation", section on 'Oropharyngeal dysphagia, gastroesophageal reflux, and gastroparesis'.)

MONITORING AND FOLLOW-UP AFTER DISCHARGE — Routine monitoring after lung transplantation is intended to prevent complications or to detect them as soon as possible. While monitoring is most intensive during the first year after transplantation, it must continue for the lifetime of the recipient. The techniques include:

●Regular contact with a trained nurse coordinator

●Check-ups by a clinician

●Chest radiographs

●Spirometry

●Bronchoscopy

●Selected blood tests to regulate the immunosuppressive medications (see "Maintenance immunosuppression following lung transplantation", section on 'Monitoring and adjusting maintenance therapy')

Each center has its own protocol, and regular communication among the recipient, the local clinician, and the staff at the transplant center is essential. We require all of our patients to complete post-transplant rehabilitation locally for up to three months, which allows us to closely monitor their progress and alert our team to any unforeseen concerns. Despite close monitoring after discharge, it is not unusual to experience relatively high 30-day readmission rates of 15 to 20 percent in our recipient cohort.

Lung function — Lung function gradually improves and usually reaches a plateau by the end of the first year after transplantation. The exact values for spirometric parameters are slightly different depending on the indication for transplantation (ie, the underlying lung disease) and the type of transplant procedure. A single center retrospective series found that after bilateral transplantation, forced vital capacity (FVC) was stable at about 67 percent predicted at one and five years, while forced expiratory volume in one second (FEV₁) declined slightly from 65 to 59 percent predicted [46]. After single lung transplant, the FVC declined from 62 to 51 percent predicted and FEV₁ declined from 51 to 40 percent predicted at one and five years, respectively.

Most programs equip their recipients with a hand-held, personal spirometer, teach them to monitor their own FVC and FEV₁, and caution them to report any downward trend in these measurements. Daily home spirometry is associated with earlier detection of bronchiolitis obliterans syndrome when compared with standard in-laboratory pulmonary function tests [47,48]. A sustained decline of 10 to 15 percent or more in FVC or FEV₁ signals a potentially significant problem [49-51]. Home spirometry is also used by some centers to identify acute allograft rejection with a sensitivity of approximately 60 percent. However, the benefit of home spirometry on long term outcomes is less clear and adherence is low beyond 6 to 12 months after transplant. (See "Chronic lung allograft dysfunction: Bronchiolitis obliterans syndrome" and "Evaluation and treatment of acute cellular lung transplant rejection", section on 'Spirometry'.)

Flexible bronchoscopy — Periodic, surveillance bronchoscopy in asymptomatic, clinically and physiologically stable recipients is controversial, and the practice varies among centers [52,53]. Our practice is to perform bronchoscopy with bronchoalveolar lavage and transbronchial biopsy at 4 weeks and at 3, 6, 9, and 12 months, or as indicated (ie, following treatment for rejection). Long-term, annual bronchoscopies are performed to rule out indolent rejection.

For patients with a clinical syndrome suggestive of acute rejection or infection, bronchoscopy with bronchoalveolar lavage is the most sensitive diagnostic study to identify the etiology of pulmonary infection and rule out atypical etiologies (eg, hemorrhage, malignancy). Due to the similar clinical presentation of rejection and infection, we normally perform transbronchial biopsies at the same time to rule out rejection [54]. Lavage specimens should be sent for standard cultures and viral polymerase chain reaction (PCR), which can be done to detect influenza, coronavirus, respiratory syncytial virus, adenovirus, parainfluenza, human metapneumovirus, and rhinovirus [53]. (See "Evaluation and treatment of acute cellular lung transplant rejection", section on 'Flexible bronchoscopy' and "Evaluation and treatment of antibody-mediated lung transplant rejection", section on 'Flexible bronchoscopy' and "Bacterial infections following lung transplantation", section on 'Diagnostic approach' and "Viral infections following lung transplantation".)

Maintenance immunosuppression — All patients undergoing lung transplantation will need lifelong maintenance immunosuppression to prevent allograft rejection. The immunosuppressive agents, drug level monitoring, and adjustments for changes in clinical status are discussed separately. (See "Induction immunosuppression following lung transplantation" and "Maintenance immunosuppression following lung transplantation".)

COMPLICATIONS — Complications following lung transplantation are discussed separately:

●Primary lung graft dysfunction (see "Primary lung graft dysfunction")

●Acute and chronic lung transplant rejection (see "Evaluation and treatment of acute cellular lung transplant rejection" and "Evaluation and treatment of antibody-mediated lung transplant rejection" and "Chronic lung allograft dysfunction: Bronchiolitis obliterans syndrome")

●Airway and vascular anastomotic complications (see "Airway complications after lung transplantation" and "Noninfectious complications following lung transplantation", section on 'Vascular anastomotic complications')

●Bacterial, fungal, and viral infection (see "Bacterial infections following lung transplantation" and "Fungal infections following lung transplantation" and "Viral infections following lung transplantation")

●Other noninfectious complications (eg, pneumothorax, chylothorax, venous thromboembolism, arrhythmias, myocardial infarction, hyperammonemia, renal insufficiency, delirium) (see "Noninfectious complications following lung transplantation" and "Pleural complications in lung transplantation")

RETRANSPLANTATION — Retransplantation is infrequent. In the International Society for Heart and Lung Transplantation (ISHLT) registry, it was the indication for <5 percent of adult lung transplants and <10 percent of pediatric procedures [2,8]. Second retransplants account for 0.1 percent.

Indications — The most common reasons for retransplantation are [55]:

●Early graft failure

●Intractable airway complications

●Chronic lung allograft dysfunction (CLAD; chronic rejection), which can be restrictive or obstructive in nature

When retransplantation is being entertained, a number of factors need to be considered. These include the timing and indication for retransplant, the presence of other comorbidities, immunosuppressive management, infection prophylaxis, and the likelihood of success.

Because of the shortage of donor lungs, retransplantation has raised many ethical issues, and retransplantation for early graft failure has been especially controversial since the outcomes are notably worse than retransplantation for late obstructive CLAD [55-58]. In general, retransplantation should be considered for carefully selected patients who are ambulatory and who would meet most, if not all, other general guidelines for a first transplant. Furthermore, bridging a patient from ECMO to retransplantation should be discouraged, and special consideration should be given to the wisdom of retransplantation in patients who are older.

Choice of procedure — The most common retransplantation procedure in patients with a previous bilateral lung transplant (BLT) is a second BLT transplant. In patients with an initial single lung transplant (SLT), a single contralateral transplant is most common [59]. (See 'Overview of the procedure' above.)

Outcomes — The choice of retransplant procedure (BLT or SLT) does not appear to affect outcome; approximately 40 percent of procedures are SLT and 60 percent are BLT [60]. Renal failure associated with prolonged immunosuppression appears to contribute to the poorer outcomes noted after retransplantation compared with initial transplantation. Alternatively, the presence of renal failure may be a surrogate marker for either the duration and intensity of immunosuppression or the degree of disease of the microcirculation in other organs (eg, the heart). In these instances, careful consideration should be given to concomitant kidney transplant. (See "Noninfectious complications following lung transplantation", section on 'Renal insufficiency'.)

Conflicting data have been reported regarding outcomes after retransplantation compared with primary transplantation [59,61-64]. As examples:

●In an ISHLT registry report, adults who underwent a first retransplantation between January 1990 and June 2012 (1673 patients), the unadjusted survival rates were: 77 percent at 3 months, 64 percent at 1 year, 37 percent at 5 years, and 20 percent at 10 years [5]. These results compare with unadjusted survival rates for primary lung transplantation of 88 percent at 3 months, 80 percent at 1 year, 53 percent at 5 years, and 32 percent at 10 years.

●In a study describing the United States experience with retransplantation after implementation of the lung allocation score (LAS, 2005 to 2011), the outcomes of 456 first-time retransplants were compared with 9270 primary transplants [65]. Analyzing retransplant patients matched for confounding variables with primary transplant recipients, no difference in survival time was noted, if transplanted more than two years from the original operation. However, those transplanted early after the initial transplant operation had notably worse survival of about 40 percent at five years. Importantly, survival following retransplantation after the LAS implementation improved considerably from before the LAS.  

●Survival of lung retransplant recipients depends in part on the type of CLAD that necessitated retransplantation: bronchiolitis obliterans syndrome (BOS) or restrictive allograft syndrome (RAS). In a series of 143 retransplant recipients composed of 94 (66 percent) with BOS and 49 with RAS, those with RAS redeveloped CLAD earlier and were more likely to redevelop RAS [58]. Additionally, survival after retransplant for RAS was worse than after retransplant for BOS, adjusted hazard ratio 2.61 (95% CI 1.51-4.51). (See "Chronic lung allograft dysfunction: Bronchiolitis obliterans syndrome" and "Chronic lung allograft dysfunction: Restrictive allograft syndrome".)

Following retransplantation, BOS develops in a greater proportion of retransplant recipients than primary lung recipients. BOS occurred within one year in 17 percent of lung retransplant recipients and in 9 percent of primary lung transplant recipients [5]. By five years, BOS occurred in 53 percent of lung retransplant recipients and in 40 percent of primary lung transplant recipients.

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Lung transplantation".)

INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5^th to 6^th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10^th to 12^th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.

Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.)

●Basics topic (see "Patient education: Lung transplant (The Basics)")

SUMMARY AND RECOMMENDATIONS

●Donor-recipient matching – When donor lungs become available, the computer system at the national transplant center assesses potential donor/recipient matches based on blood type, size of the organ, and distance between the donor and recipient. Once the recipient is identified, arrangements are made to retrieve the lung allograft from the donor, preserve and transport the allograft, and prepare the recipient for surgery. (See 'Preparation' above.)

●Lung transplant procedures

•Single lung transplantation (SLT) is performed through posterolateral, anterolateral, or median sternotomy incisions. Protective ventilation strategies are employed during one lung ventilation (OLV) to minimize lung injury. (See 'Overview of the procedure' above.)

•Bilateral lung transplantation (BLT) is performed through a transverse thoracosternotomy, bilateral anterolateral incisions, or median sternotomy (which requires full cardiopulmonary bypass). If disease in the native lung is fairly uniformly distributed, the right side is often performed first; otherwise, the native lung with the worst function is transplanted first. During BLT, the lungs are implanted separately and sequentially, using OLV to the opposite lung in sequence. (See 'Overview of the procedure' above.)

•Living donor lobar transplantation is an infrequently used option for carefully selected recipients who seem unlikely to survive until cadaveric lungs become available. (See 'Living donor lobar transplantation' above.)

•Cadaveric lobar transplants (CLT) can be a useful strategy for rapidly deteriorating candidates on the wait list. It is most appropriate for pediatric patients and small adults with pulmonary fibrosis or cystic fibrosis. (See 'Cadaveric lobar transplants' above.)

●Bronchial anastomosis – The bronchial anastomosis is a particularly vulnerable site for complications, as the bronchial blood supply to the donor airway is disrupted during transplantation. The bronchial anastomosis is typically performed using an end-to-end technique. Neither omental wrapping nor bronchial revascularization has reduced airway complications and are not commonly employed strategies today. (See 'Bronchial anastomosis' above.)

●Extracorporeal life support (ECLS) – ECLS is generally needed for pediatric recipients, adult recipients with pulmonary vascular disease, and in about one-third of other patients. ECLS can be provided via cardiopulmonary bypass (CPB), veno-arterial (VA)-extracorporeal membrane oxygenation (ECMO), or veno-venous (VV)-ECMO (in cases where cardiac support is not needed). VA-ECMO is often preferred over CPB due to the decreased risk of bleeding complications. (See 'Extracorporeal life support' above.)

●Mechanical ventilation and weaning – The postoperative settings for mechanical ventilation are dependent on the underlying lung disease and whether a native (diseased) lung is still present, but generally follow a "lung protective" strategy with a low tidal volume (eg, 6 mL/kg predicted body weight) and maintenance of the plateau pressure ≤30 cm H₂O. Positive end-expiratory pressure (PEEP) greater than 5 cm H₂O is avoided after SLT for chronic obstructive pulmonary disease (COPD), but PEEP 5 to 10 cm H₂O is typical after SLT for other indications and after BLT. Weaning may be prolonged in patients transplanted for pulmonary hypertension. (See 'Ventilatory support and weaning' above.)

●Primary graft dysfunction (PGD) – PGD represents a multifactorial injury to the transplanted lung occurring in the first 72 hours after implantation. Inhaled nitric oxide (iNO) and ECMO may be useful in the management of severe cases of PGD. (See 'Management of primary graft dysfunction' above and "Primary lung graft dysfunction", section on 'Treatment'.)  

●Initiation of immunosuppression – All patients undergoing lung transplantation require immunosuppressive therapy to prevent acute and chronic allograft rejection. Specifics vary among transplant centers, but our approach is to give tacrolimus in the preoperative holding area (when the donor is deemed acceptable), and then basiliximab (for induction therapy), mycophenolate mofetil, and methylprednisolone intraoperatively. A three-drug maintenance regimen is begun postoperatively. (See 'Initiation of immunosuppression' above and "Induction immunosuppression following lung transplantation" and "Maintenance immunosuppression following lung transplantation".)

●Infection prophylaxis – Empiric prophylaxis against bacterial, fungal, and viral infection is routinely administered perioperatively. Coverage may be expanded to potential pathogens that are isolated from the donor or recipient. In the absence of specific culture results, most centers use an empiric initial regimen and adjust it based on culture results. (See 'Infection prophylaxis' above.)

●Monitoring after lung transplantation

•Lung function generally improves up to 12 months after transplant. Subsequent declines may be an early sign of rejection. Home monitoring of forced vital capacity and forced expiratory volume in one second is used by many transplant centers to identify rejection. (See 'Lung function' above.)

•Routine surveillance transbronchial biopsy is controversial, but our practice is to perform bronchoscopy with bronchoalveolar lavage and transbronchial biopsy at 4 weeks and at 3, 6, 9, and 12 months, or as indicated (ie, following treatment for rejection). Long-term, annual bronchoscopies are performed to rule out indolent rejection. (See 'Flexible bronchoscopy' above.)

●Retransplantation – Retransplantation should be considered only for carefully selected patients who meet most, if not all, other general guidelines for a first transplant. Retransplantation for chronic lung allograft dysfunction (CLAD) due to bronchiolitis obliterans syndrome (BOS) has a significantly better outcome than retransplantation for CLAD due to restrictive allograft syndrome (RAS), airway dehiscence, or acute primary graft failure. (See 'Retransplantation' above.)

ACKNOWLEDGMENTS — The UpToDate editorial staff acknowledges Marcelo Cypel, MD, MSc, FRCSC, Tom Waddell, MD, MSc, PhD, FRCS, FACS, and Shaf Keshavjee, MD, MSc, FRCSC, FACS, who contributed to earlier versions of this topic review.