What's new in surgery

The following represent additions to UpToDate from the past six months that were considered by the editors and authors to be of particular interest. The most recent What's New entries are at the top of each subsection.

ABDOMINAL WALL AND HERNIA SURGERY

Updated analysis on the risks and benefits of paraesophageal hernia repair (March 2024)

Paraesophageal hernia repair has not been advised for asymptomatic patients due to a high perioperative mortality relative to the risk of developing symptoms. However, in an updated Markov analysis of surgery versus expectant management for such patients, the mortality of elective laparoscopic repair was reduced to <0.5 percent, while the mortality of emergency repair remained high at 10 percent on average [1]. The annual probabilities of developing symptoms that would necessitate elective and emergency surgery were estimated to be 5.8 and 1.7 percent, respectively. Based on this new analysis, patients with a paraesophageal hernia should be referred for surgical consultation regardless of symptoms to determine if they are an appropriate candidate for hernia repair. In particular, older patients have a higher incidence of paraesophageal hernia and should not be denied surgical consultation. (See "Surgical management of paraesophageal hernia", section on 'Indications for surgical repair'.)

COLORECTAL SURGERY

Postoperative antibiotics in children with gangrenous appendicitis (April 2024)

For children with gangrenous appendicitis (microperforation with bacterial contamination outside of the appendix), the role of postoperative antibiotics (pABx) is being reevaluated. In a retrospective study of over 950 children with gangrenous appendicitis (573 who received pABx), unadjusted rates of postoperative surgical site infections were low in patients who did or did not receive pABx (3.3 and 2.1 percent, respectively). With propensity-matching in 404 patients to address treatment by intention, rates remained similar for surgical site infection, postoperative abdominal imaging, and hospital revisits [2]. These findings challenge the traditional practice of giving pABx to children with gangrenous appendicitis and provide a basis for future randomized trials. (See "Acute appendicitis in children: Management", section on 'Postoperative care'.)

Lack of overall survival benefit for primary tumor resection in metastatic colorectal cancer (April 2024)

For patients with unresectable metastatic colorectal cancer (CRC) and an asymptomatic primary tumor, randomized trials are evaluating the benefits of upfront primary tumor resection. In a combined analysis of two multicenter, randomized clinical trials in almost 400 such patients, primary tumor resection prior to initial systemic therapy failed to improve overall survival compared with immediate systemic therapy (median 17 versus 19 months, hazard ratio 0.94) [3]. Based on these data and the potential risks of surgery, we recommend against upfront primary tumor resection for patients with unresectable metastatic CRC and an asymptomatic primary tumor. (See "Locoregional methods for management of metastatic colorectal cancer", section on 'Unresectable metastatic disease'.)

Antibiotics are required for nonoperative management of uncomplicated appendicitis (April 2024)

In uncomplicated appendicitis, antibiotic therapy alone is a widely accepted alternative to appendectomy. Whether antibiotic therapy can be omitted in some patients is unknown. In a trial that randomly assigned 100 patients with mild appendicitis (defined as white blood cell count <13,000/microliter, C-reactive protein <60 mg/dL) to piperacillin-tazobactam or observation for either disease regression or the need for surgical exploration, antibiotic therapy reduced the need for appendectomy both during the initial hospitalization (28 versus 53 percent) and at three-year follow-up (50 versus 63 percent) [4]. Thus, we continue to suggest routine antibiotic therapy for all patients managed nonoperatively for acute appendicitis. (See "Management of acute appendicitis in adults", section on 'Protocols'.)

Duration of antibiotic therapy following appendectomy for perforated appendicitis (February 2024)

The duration of antibiotic therapy following appendectomy for perforated appendicitis is debated. In a trial of 104 patients with complicated appendicitis (defined as gangrenous or perforated) who received 24 hours of intravenous or oral amoxicillin-clavulanate, the 30-day complication rate was not different (15 percent in both groups) [5]. Because the study population was dominated by patients with gangrenous appendicitis (75 percent) and 67 percent of organ/space infections occurred in patients with perforated appendicitis, these findings may not be generalizable to the latter group. Thus, until further data are available, we continue to suggest two to four days of intravenous antibiotics after appendectomy for those with perforated appendicitis, based on data from previous trials. (See "Management of acute appendicitis in adults", section on 'Antibiotics for perforated appendicitis'.)

BREAST SURGERY

Surgical axilla evaluation for clinically node-negative breast cancer (May 2024)

Patients with clinically node-negative breast cancer typically undergo sentinel lymph node biopsy (SLNB). If ≤2 SLNs are positive and whole breast radiation is planned, completion of axillary lymph node dissection (ALND) is not required. The recent SENOMAC trial randomly assigned 2540 patients with T1 to T3 breast cancer and one or two SLNs containing macrometastasis (>2 mm) to either completion or omission of ALND [6]. Most patients in both groups received radiation including nodal target volumes. Recurrence-free survival was similar for both groups at 47 months median follow-up. Based on these and prior results, we recommend omitting completion of ALND in patients with clinically node-negative, T1, T2, or T3 breast cancer who are undergoing breast-conserving surgery or mastectomy with SLNB, have fewer than three SLNs containing metastasis, and plan to undergo postsurgical radiation. (See "Overview of sentinel lymph node biopsy in breast cancer", section on 'One or two sentinel node metastases'.)

Use of axillary ultrasound to guide omission of sentinel node biopsy in early breast cancer (April 2024)

Approaches to treatment de-escalation for early breast cancer are under investigation. In a randomized trial that included nearly 1500 females with stage I (<2 cm) breast cancer and negative axillary ultrasound, those assigned to sentinel lymph node biopsy (SLNB) versus no axillary surgery at the time of primary breast surgery experienced similar rates of axillary recurrence, as well as disease-free and overall survival [7]. Omitting surgical axillary staging did not impact the selection of adjuvant treatment, although the study population was dominated by patients with low-risk cancers (93 percent with estrogen receptor-positive, HER2-negative disease). Despite these results, we continue to obtain SLNB in most patients with a clinically negative axilla (by examination and imaging), given that it can influence adjuvant treatment selection and administration, particularly for younger patients. (See "Overview of management of the regional lymph nodes in breast cancer", section on 'Can ultrasound identify patients who can omit sentinel node biopsy?'.)

ENDOCRINE SURGERY

Risk of autoimmune disease after surgical cure of Cushing disease (February 2024)

In patients with a corticotropin (ACTH)-secreting pituitary tumor (Cushing disease), transsphenoidal surgery with adenomectomy provides a high rate of initial cure. Surgical cure of Cushing disease improves skeletal and cardiometabolic health, but it also may contribute to increased risk of autoimmune disorders. In a retrospective study in predominantly female adults (mean age approximately 44 years) with pituitary adenoma who underwent successful surgical management, patients with Cushing disease (n = 194) had a higher rate of new-onset autoimmune disease following surgery compared with patients with a nonfunctioning adenoma (n = 92; cumulative three-year incidence 10.4 versus 1.6 percent, respectively) [8]. Autoimmune thyroid disease was most common, and family history of autoimmune disease was associated with higher risk of developing an autoimmune disorder. These findings support the need for long-term monitoring of patients with Cushing disease, even after curative surgical treatment. (See "Primary therapy of Cushing disease: Transsphenoidal surgery and pituitary irradiation", section on 'Long-term health risks'.)

Cardiometabolic features of adrenal incidentaloma with mild autonomous cortisol secretion (December 2023)

In some individuals with adrenal incidentaloma, mild autonomous cortisol secretion (MACS) is evident in the absence of clinical features of Cushing syndrome. The long-term risks of MACS and optimal management strategies are not well defined. In a meta-analysis of 47 observational studies in 17,156 patients with adrenal incidentaloma, individuals with MACS (defined as serum cortisol >1.8 mcg/dL after a 1 mg overnight dexamethasone suppression test) exhibited a higher prevalence of diabetes, hypertension, and dyslipidemia compared with individuals with nonfunctioning adrenal adenomas [9]. Further, patients with MACS who underwent adrenalectomy showed greater improvement in cardiometabolic parameters than those who did not undergo surgery. These findings demonstrate the potential cardiometabolic risks of MACS and support our preference for adrenalectomy in patients with MACS and younger age or evidence of cardiometabolic dysregulation. (See "Evaluation and management of the adrenal incidentaloma", section on 'Clinical manifestations'.)

PERIOPERATIVE CARE

Anti-factor Xa levels 24 hours after the last therapeutic enoxaparin dose (April 2024)

Guidelines recommend waiting 24 hours after a therapeutic dose of low molecular weight heparin (LMWH) before performing neuraxial anesthesia, to minimize the risk of spinal epidural hematoma (SEH). However, anti-factor Xa levels (which test LMWH activity) may still be elevated 24 hours after the last dose. In a study of 103 patients taking therapeutic dose enoxaparin, 23 percent had an anti-factor Xa level ≥0.2 international units/mL at ≥24 hours after the last dose [10]. The implications of these findings are unclear, as a safe anti-factor Xa level for performing neuraxial procedures has not been determined and there has not been a noticeable increase in SEH in patients who have withheld LMWH according to current guidelines. (See "Neuraxial anesthesia/analgesia techniques in the patient receiving anticoagulant or antiplatelet medication", section on 'Therapeutic LMWH'.)

Obesity and increased risk of perioperative cardiac arrest (March 2024)

Obesity is a risk factor for difficulty with airway management and for rapid apneic oxygen desaturation during airway management. Both can result in hypoxic brain damage or death. In an analysis of causes of perioperative cardiac arrest reported to the Seventh National Audit Project (NAP7) in the United Kingdom, 35 percent of airway- and respiratory-related cardiac arrests occurred in patients with body mass index 35 to 50 kg/m², while this cohort comprised only 12 percent of the survey population [11]. These findings reinforce the need to consider obesity when choosing general versus regional anesthesia and planning the airway management strategy. (See "Airway management for induction of general anesthesia", section on 'Obesity as a risk factor'.)

Postoperative noninvasive ventilation or high-flow nasal oxygen for patients with obesity (November 2023)

The optimal postoperative ventilatory strategy for patients with severe obesity has been unclear. In a 2023 network meta-analysis of randomized trials that compared various postoperative noninvasive ventilatory strategies in these patients, high-flow nasal oxygen (HFNO) or bilevel positive airway pressure (BiPAP) reduced atelectasis; HFNO, BiPAP, or continuous positive airway pressure (CPAP) reduced postoperative pneumonia; and HFNO reduced length of stay compared with conventional oxygen therapy [12]. For patients with obesity who are hypoxic in the post-anesthesia care unit despite oxygen supplementation and incentive spirometry, we suggest a trial of HFNO, BiPAP, or CPAP prior to considering intubation. (See "Anesthesia for the patient with obesity", section on 'Post-anesthesia care unit management'.)

SKIN AND SOFT TISSUE SURGERY

Lymphatic venous bypass reduces cellulitis frequency in patients with lower extremity lymphedema (March 2024)

Observational studies suggest lymphatic venous bypass procedures provide benefits beyond limb volume reduction. In a trial comparing lymphatic venous anastomosis (LVA) plus complex decongestive therapy (CDT) versus CDT alone in patients with lower extremity lymphedema, LVA resulted in a greater reduction in cellulitis frequency from baseline (0.57 versus 0.21 fewer episodes over six months) [13]. LVA also reduced thigh area hardness; however, limb circumference and pain were similar. All patients had undergone at least three months of CDT before randomization. The outcomes of this trial support our practice of offering LVA for patients with lymphedema and recurrent cellulitis. (See "Surgical treatment of primary and secondary lymphedema", section on 'Lymphatic bypass outcomes'.)

TRAUMA AND BURN SURGERY

Validation of a low-risk rule for children with blunt abdominal trauma (May 2024)

The Pediatric Emergency Care Applied Research Network (PECARN) has previously derived a clinical prediction rule in children with blunt abdominal trauma who are at low risk for intraabdominal injury (IAI) that requires acute intervention (eg, laparotomy, blood transfusion, or prolonged hospitalization). The PECARN rule has now been validated in a multicenter, prospective cohort of over 7500 children with blunt abdominal trauma [14]. As in the derivation cohort, the rule identified patients at low risk of IAI requiring acute intervention with high sensitivity (100 percent) and negative predictive value (100 percent; prevalence of IAI requiring acute intervention, 2 percent). Based on these findings, children at low risk according to the PECARN rule do not require abdominal and pelvic computed tomography during initial evaluation. (See "Pediatric blunt abdominal trauma: Initial evaluation and stabilization", section on 'PECARN low-risk rule'.)

Skin preparation prior to fracture repair (March 2024)

The optimal preparation of contaminated or dirty wounds and whether any skin preparation can influence surgical site infection (SSI) independent of other factors (eg, prophylactic systemic antibiotics) are unknown. In a multiple-period, cluster-randomized, crossover trial comparing skin preparation with iodine povacrylex in alcohol versus chlorhexidine gluconate in alcohol in 1700 open fracture repairs, the incidence of superficial or deep SSI was similar for both approaches [15]. Based on these findings, which are consistent with those from a previous trial, either chlorhexidine- or iodine-based skin preparations can be used prior to surgery for open, traumatic lower extremity wounds. (See "Surgical management of severe lower extremity injury", section on 'Limb preparation and skin antisepsis'.

Whole blood transfusion for severe traumatic hemorrhage (January 2024)

For severe traumatic hemorrhage, whole blood transfusion is an alternative to balanced component transfusion (1:1:1 ratio of packed red blood cells/plasma/platelets). In an observational study comparing these two approaches, low titer group O whole blood transfusion was associated with lower 24-hour mortality (8 versus 19 percent) and lower volume of blood products received at 72 hours (48 versus 82 mL/kg) [16]. The survival benefit was greatest in patients with shock or coagulopathy. While this study suggests improved outcomes for whole blood transfusion, randomized trials are needed to determine which transfusion strategy might be superior and which patients would benefit the most. (See "Ongoing assessment, monitoring, and resuscitation of the severely injured patient", section on 'Whole blood transfusion'.)

VASCULAR AND ENDOVASCULAR SURGERY

Phosphodiesterase type 5 inhibition for Raynaud phenomenon (January 2024)

Phosphodiesterase type 5 (PDE5) inhibitors such as sildenafil and tadalafil are widely used to treat digital ischemia from Raynaud phenomenon. In an updated meta-analysis of nine randomized trials comprising 411 patients with Raynaud phenomenon (most of whom had scleroderma), treatment with PDE5 inhibition resulted in three fewer attacks weekly and a reduction in the average duration of the attacks by five minutes [17]. However, PDE5 inhibition led to minimal to no reduction in the pain associated with Raynaud phenomenon. This study implies that while PDE5 inhibition has a modest impact on the duration and frequency of Raynaud attacks, it might not be adequate to address all symptoms experienced by patients with severe disease. (See "Treatment of Raynaud phenomenon: Initial management", section on 'Phosphodiesterase type 5 inhibitor'.)

OTHER SURGICAL SPECIALTIES

Predicting venous thromboembolism risk in non-major orthopedic surgery (April 2024)

For patients with non-major extremity orthopedic injury or surgery, deciding who should undergo venous thromboembolism (VTE) prophylaxis is challenging due to the wide range of risk. The Thrombosis Risk Prediction for Patients with cast immobilization or TRiP(cast) score, which predicts VTE risk, was recently derived and validated in nearly 5000 patients with prolonged lower limb casting, mostly for ankle sprain [18]. Among those assessed as low VTE risk (score <7) and in whom anticoagulation was withheld, the rate of symptomatic VTE was 0.7 percent compared with 2.7 percent among those with a score ≥7 despite anticoagulation. The negative predictive value for this threshold was 99 percent. Use of the score reduced the prescription of anticoagulants by 26 percent compared with baseline prescription levels. While promising, further validation is needed. (See "Prevention of venous thromboembolism (VTE) in adults with non-major extremity orthopedic injury with or without surgical repair", section on 'Venous thromboembolism risk'.)

Moderate hypothermia during aortic arch surgery with antegrade cerebral perfusion (March 2024)

Observational data have supported a shift from deep to moderate hypothermia during circulatory arrest for aortic arch surgery, particularly with adjunctive antegrade cerebral perfusion (ACP). A recent trial has now compared outcomes for 251 patients undergoing aortic arch surgery with ACP and randomly assigned to deep (≤20.0°C), low-moderate (20.1 to 24.0°C), or high-moderate (24.1 to 28.0°C) circulatory arrest temperature [19]. At one-month follow-up, the three groups had similar neurocognitive and neuroimaging outcomes and similar mortality, major morbidity, and quality of life. The volume of transfused blood products was higher in the deep group, but transfusion-related complications were not different. Based on this trial, moderate (20.1 to 28.0°C) rather than deep hypothermia is reasonable during aortic arch surgery when ACP is also used. Whether a low-moderate or high-moderate temperature is selected depends on the complexity of the arch intervention and the anticipated duration of hypothermia. (See "Overview of open surgical repair of the thoracic aorta", section on 'Hypothermic circulatory arrest'.)

Complications of transrectal versus transperineal prostate biopsy (February 2024)

The merit of transrectal versus transperineal prostate biopsy has been vigoroulsy debated. In the first randomized trial comparing these procedures in over 760 patients undergoing biopsies in the office setting, the two approaches had similar rates of both infectious (2.6 versus 2.7 percent) and non-infectious (1.7 versus 2.2 percent) complications [20]. This suggests that both approaches can be performed with a low risk of complications. Antibiotic prophylaxis was given to all patients prior to transrectal biopsy but omitted in most patients undergoing transperineal biopsy. (See "Prostate biopsy", section on 'Transrectal versus transperineal biopsy'.)

Pregnancy and childbirth after urinary incontinence surgery (January 2024)

Patients with stress urinary incontinence (SUI) have historically been advised to delay midurethral sling (MUS) surgery until after childbearing because of concerns for worsening SUI symptoms following delivery. In a meta-analysis of patients with MUS surgery who were followed for a mean of nearly 10 years, similar low SUI recurrence and reoperation rates were reported for the 381 patients with and the 860 patients without subsequent childbirth [21]. Birth route did not affect the findings. Although the total number of recurrences and reoperations was small, this study adds to the body of evidence suggesting that subsequent childbirth does not worsen SUI outcomes for patients who have undergone MUS. (See "Surgical management of stress urinary incontinence in females: Retropubic midurethral slings", section on 'Subsequent pregnancy'.)

Tranexamic acid to reduce bleeding after percutaneous nephrolithotomy (December 2023)

Postoperative bleeding can occur after percutaneous nephrolithotomy (PNL) for kidney stone removal; most bleeding is venous in origin and can be managed with conservative measures. A recent meta-analysis of 10 randomized trials found that use of tranexamic acid (TXA), an antifibrinolytic agent used to reduce bleeding in other clinical settings, may reduce the risk of blood transfusion after PNL [22]. Most trials were conducted in low- to middle-income settings in populations that were younger than those in higher-income settings; whether these findings are generalizable to practice in higher-income settings is uncertain. Pending additional data, we do not routinely use TXA after PNL. (See "Kidney stones in adults: Surgical management of kidney and ureteral stones", section on 'Bleeding'.)

Choice of intervention for aortic stenosis with low surgical risk (November 2023)

The choice of intervention for severe aortic stenosis (AS) is based upon an individualized assessment by a multidisciplinary heart valve team. Two randomized trials reported outcomes for transcatheter aortic valve implantation (TAVI) and surgical aortic valve replacement (SAVR) in selected low surgical risk patients with severe AS [23,24]:

●In one trial in which nearly 1500 patients were randomly assigned to TAVI with a self-expanding valve or SAVR, rates of mortality, disabling stroke, and aortic valve rehospitalization at four years were similar in the two groups.

●In another trial in which 1000 patients were randomly assigned to TAVI with a balloon-expanding valve or SAVR, rates of mortality, stroke, and rehospitalization at five years were similar in the two groups.

These trials indicate generally favorable results for TAVI up to four and five years for selected low surgical risk patients with severe AS and anatomical suitability for TAVI; additional data, including longer-term outcomes, will further inform the choice of intervention in this clinical setting. (See "Choice of intervention for severe calcific aortic stenosis", section on 'In low-risk symptomatic patients'.)

OTHER GENERAL SURGERY

Acetaminophen use in pregnancy not associated with adverse neurodevelopment in offspring (April 2024)

Although older studies raised concerns about a possible adverse association between in utero exposure to acetaminophen and neurodevelopment, more recent studies with a lower risk of bias have not reported an association. In a population-based study in which acetaminophen use was prospectively recorded, siblings with any in utero exposure had no increased risk for attention deficit hyperactivity disorder, autism spectrum disorder, or intellectual disability at age 10 years compared with their unexposed siblings [25]. Although an association cannot be definitively excluded, these data are reassuring when a short course of acetaminophen is desirable to manage pain or fever during pregnancy. (See "Prenatal care: Patient education, health promotion, and safety of commonly used drugs", section on 'Acetaminophen'.)