Partial gastrectomy and gastrointestinal reconstruction

INTRODUCTION — Partial gastric resection is used to treat cases of benign gastric disease for which resection is indicated; to treat malignant gastric tumors, such as adenocarcinoma, where sufficient margins can be achieved; to treat selected cases of gastrointestinal stromal tumor; and to manage complications related to conservative management of lymphomas.

The extent of gastric resection and type of reconstruction chosen impacts the nature of perioperative and later complications, particularly the development of postgastrectomy syndromes. In Japan and other countries where the incidence of early gastric cancer is high, function-preserving techniques, including proximal gastrectomy and pylorus-preserving gastrectomy, have been promoted. The role of these techniques in treating patients in Western countries has not been well studied given most patients are diagnosed at a late stage.

The indications and techniques for partial gastric resection and reconstruction, perioperative care, and complications will be reviewed here. Total gastrectomy and reconstruction are discussed separately. (See "Total gastrectomy and gastrointestinal reconstruction".)

SURGICAL ANATOMY AND PHYSIOLOGY OF THE STOMACH — The stomach is located in the left upper quadrant of the abdomen. Anteriorly, the stomach is related to the left lateral lobe of the liver, diaphragm, colon, omentum, and anterior abdominal wall (figure 1). Posteriorly, the stomach is associated with the pancreas, spleen, left kidney and adrenal gland, splenic artery, and left diaphragm (figure 2 and figure 3).

The stomach is divided anatomically into five sections, with each section based upon histologic differences and each having a unique role in the process of digestion (figure 4). These sections include [1] (see "Physiology of gastric acid secretion"):

●Cardia – The proximal portion of the stomach adjacent to the lower esophageal sphincter. It contains mucus neck cells and endocrine cells.

●Fundus – The portion of the stomach that rises above the level of the cardiac opening. It contains parietal cells, chief cells, endocrine cells, and mucus neck cells.

●Body – The portion of the stomach that lies between the fundus and the antrum. It contains cell types that are similar to the fundus.

●Antrum – The distal portion of the stomach demarcated from the body of the stomach on the lesser curvature by the angular incisura. It contains pyloric glands, endocrine cells, mucus neck cells, and G cells.

●Pyloric sphincter – A thick muscular valve separating the antrum from the duodenum. It contains mucus neck cells and endocrine cells.

The blood supply to the stomach is predominantly derived from the branches of the celiac artery (figure 1). The left gastric artery, which is derived from the celiac artery, courses along the lesser curvature of the stomach and anastomoses with the right gastric artery, which is a branch of the common hepatic artery. The right and left gastroepiploic arteries arise from the gastroduodenal artery and splenic arteries, respectively, and anastomose along the greater curvature. The short gastric arteries arise from the splenic artery and supply the fundus of the stomach. The gastric veins (left and right) parallel the arterial supply draining into the portal vein.

When entering the lesser sac through the gastrohepatic ligament, the surgeon should take care to avoid injury to the hepatic branch of the right vagus nerve (figure 5), or a replaced or accessory left hepatic artery arising from the left gastric artery, which occurs in approximately 10 percent of the population (figure 6).

Lymphatic drainage — For patients with gastric cancer, lymphadenectomy is performed in concert with the gastric resection. The lymph node stations (table 1), as defined by the Japanese Gastric Cancer Association, are grouped according to location (figure 7) and follow the extent of potential lymph node dissection (D1 through D3) [2]. (See 'Lymph node dissection' below.)

●Perigastric lymph nodes – Refers to lymph nodes attached directly to the stomach along the greater and lesser curvatures

●Perivascular lymph nodes – Refers to lymph nodes along the gastric (left and right), gastroepiploic, hepatic (left and right), celiac, splenic, or mesenteric vessels

●Peripyloric – Refers to lymph nodes above and below the pylorus

●Peripancreatic – Refers to lymph nodes in the region of the pancreas

●Periaortic – Refers to lymph nodes in the vicinity of the aorta

INDICATIONS — Partial gastrectomy may be indicated in the treatment of various stomach diseases both malignant and benign or, rarely, in the management of devascularization injuries of the stomach due to trauma or other insults.

Malignant tumors — Whether partial gastrectomy is appropriate for the management of malignant tumors of the stomach depends upon the ability to control local disease by obtaining an appropriate margin [3]. In patients with malignant tumors, partial gastric resection and reconstruction may be indicated primarily, in combination with neoadjuvant therapy, to manage complications, or, in select circumstances, to treat tumor recurrence [4]. The management of individual tumors for which partial gastrectomy may be indicated is discussed in detail elsewhere and includes:

●Adenocarcinoma. (See "Early gastric cancer: Treatment, natural history, and prognosis" and "Surgical management of invasive gastric cancer".)

●Gastrointestinal stromal tumors. (See "Local treatment for gastrointestinal stromal tumors, leiomyomas, and leiomyosarcomas of the gastrointestinal tract".)

●Neuroendocrine tumors. (See "Staging, treatment, and post-treatment surveillance of non-metastatic, well-differentiated gastrointestinal tract neuroendocrine (carcinoid) tumors" and "Multiple endocrine neoplasia type 1: Management" and "Management and prognosis of the Zollinger-Ellison syndrome (gastrinoma)".)

●Lymphoma. Surgery does not play a role in the primary treatment of most patients with gastric mucosa-associated lymphoid tissue (MALT) or non-MALT (diffuse large B cell) lymphomas, except to manage gastric perforation or bleeding not amenable to endoscopic management [5-7]. (See "Treatment of extranodal marginal zone lymphoma of mucosa associated lymphoid tissue (MALT lymphoma)".)

Benign tumors — Leiomyoma is the most common benign tumor for which partial gastric resection is performed [8]. Partial gastric resection has also been described in the diagnosis and/or treatment of less common submucosal lesions, including lipoma/adenomyoma and juvenile polyposis [9,10]. (See "Local treatment for gastrointestinal stromal tumors, leiomyomas, and leiomyosarcomas of the gastrointestinal tract".)

Ulcer disease — Antrectomy/distal gastrectomy may be required to manage ulcer disease but is a treatment of last resort only after conservative management, including eradication of Helicobacter pylori, has failed. Partial gastrectomy may also be indicated to manage complications of ulcer disease (eg, gastric outlet obstruction, bleeding, perforation) or if there is a suspicion of adenocarcinoma. (See "Surgical management of peptic ulcer disease".)

Antrectomy/distal gastrectomy may also be necessary to remove the source of hypergastrinemia in selected patients with Zollinger-Ellison syndrome or in those with type I (not associated with multiple endocrine neoplasia [MEN]) or type II (associated with MEN-1) gastric carcinoid, with the extent of resection determined by the size and number of lesions. Patients with type III gastric (sporadic) carcinoid may require antrectomy/distal gastrectomy or total gastrectomy with extended lymph node dissection. (See "Management and prognosis of the Zollinger-Ellison syndrome (gastrinoma)" and "Staging, treatment, and post-treatment surveillance of non-metastatic, well-differentiated gastrointestinal tract neuroendocrine (carcinoid) tumors".)

Bariatric or metabolic surgery — Partial gastric resection, in the form of sleeve gastrectomy, has been used in the management of obesity. (See "Laparoscopic sleeve gastrectomy".)

Trauma — Partial gastric resection may be necessary to manage significant injuries to the stomach. Because the stomach is well vascularized, resection is typically limited to the removal of devitalized tissue. (See "Traumatic gastrointestinal injury in the adult patient".)

CONTRAINDICATIONS — Contraindications to abdominal surgery, in general, include systemic comorbidities that preclude safe administration of anesthesia. (See 'Medical risk assessment' below.)

Contraindications for patients with ulcer disease — Antrectomy for ulcer disease should not be performed if pyloric inflammation prevents safe dissection and preservation of surrounding structures (eg, portal triad, pancreas). Surgical bypass in the form of a gastroenterostomy may be a better option. Patients with recurrent, severe, and/or unusual disease (significant duodenal ulceration) should be screened for gastrinoma prior to surgical intervention. (See "Zollinger-Ellison syndrome (gastrinoma): Clinical manifestations and diagnosis", section on 'Diagnosis'.)

Contraindications for patients with malignant disease — The ability to offer partial gastrectomy for malignant disease will depend upon the type of tumor, the extent of local disease, the ability to achieve appropriate surgical margins, and the presence of metastatic disease.

●Most surgeons would treat proximally placed malignant adenocarcinoma of the stomach with a total gastrectomy rather than a proximal subtotal gastrectomy. The exception is early gastric cancer (cT1), which can be treated with a function-preserving proximal gastrectomy. (See 'Proximal gastrectomy' below.)

●An important contraindication to partial gastrectomy is presumed or proven hereditary diffuse gastric cancer (HDGC). Total gastrectomy with intraoperative mucosal assessment to ensure negative proximal and distal margins for gastric tissue is a more appropriate treatment for most patients with HDGC. (See "Surgical management of hereditary diffuse gastric cancer".)

●Gastrectomy cannot be justified in patients with metastatic adenocarcinoma of the stomach unless complications such as obstruction, bleeding, or perforation cannot be managed using other means (see "Local palliation for advanced gastric cancer"). For incurable advanced gastric cancer, chemotherapy is the standard of care. In a randomized trial (REGATTA), gastrectomy followed by chemotherapy did not show any survival benefit compared with chemotherapy alone [11]. (See "Initial systemic therapy for locally advanced unresectable and metastatic esophageal and gastric cancer".)

●Patients with metastatic gastrointestinal stromal tumors should be managed by a multidisciplinary team, including surgery and medical oncology. Resection should be reserved for patients with complications or those showing minimal response of the symptomatic primary tumor to targeted therapies such as imatinib. (See "Adjuvant and neoadjuvant therapy for gastrointestinal stromal tumors".)

TUMOR STAGING — Patients undergoing partial gastric resection for malignancy should undergo preoperative staging to the extent that is possible, including computed tomography (CT) of the abdomen, or endoscopic ultrasound, to evaluate the extent of locoregional disease and the presence of metastatic disease, which may contraindicate the resection. (See "Clinical features, diagnosis, and staging of gastric cancer" and "Surgical management of invasive gastric cancer", section on 'Staging evaluation'.)

Staging laparoscopy is indicated for many patients with gastric adenocarcinoma [12,13]; however, the selection of patients who need staging laparoscopy is controversial. Most experts recommend staging laparoscopy for patients who have locally advanced disease (T3 or T4), have nodal metastasis (N+), or may require multivisceral resection [14,15].

The laparoscopy may be performed as a standalone procedure or just prior to the planned gastrectomy. As neoadjuvant chemotherapy becomes more commonly used in gastric cancer, diagnostic laparoscopy is increasingly performed as a standalone procedure prior to the initiation of chemotherapy. This timing allows all involved to have information regarding the curability of the tumor prior to embarking on a treatment plan. (See "Surgical management of invasive gastric cancer", section on 'Staging laparoscopy'.)

PREOPERATIVE PREPARATION

Medical risk assessment — The preoperative assessment prior to gastric resection should identify the presence of medical comorbidities. Most gastric resections are performed under elective circumstances for which there is adequate time for risk assessment and optimization of the patient's medical status. Preoperative medical assessment is discussed elsewhere. (See "Evaluation of cardiac risk prior to noncardiac surgery" and "Evaluation of perioperative pulmonary risk" and "Preoperative medical evaluation of the healthy adult patient".)

Antibiotic prophylaxis — Antibiotic prophylaxis is recommended for procedures that enter into the lumen of the gastrointestinal tract. Appropriate antibiotic choices for gastrectomy are given in the table (table 2). In addition, patients who have either a higher risk of potential colon injury or could potentially require en bloc resection of the colon should receive additional antibiotic prophylaxis against colonic flora (eg, metronidazole). (See "Antimicrobial prophylaxis for prevention of surgical site infection following gastrointestinal procedures in adults".)

Thromboprophylaxis — Thromboprophylaxis should be administered according the patient's risk for thromboembolism (table 3). Patients undergoing partial gastrectomy for malignancy are at moderate-to-high risk for thromboembolism, and pharmacologic prophylaxis is recommended. For all patients, we use intermittent pneumatic compression, which should be placed prior to induction of anesthesia and continued until the patient is ambulatory. (See "Prevention of venous thromboembolic disease in adult nonorthopedic surgical patients".)

GENERAL CONSIDERATIONS

Anesthesia — Partial gastrectomy is performed under general anesthesia. For patients undergoing upper abdominal surgery, a transversus abdominis plane block or thoracic epidural anesthesia may simplify postoperative pain management and allow early postoperative mobilization, which may expedite the return of gastrointestinal function. They are a part of the enhanced recovery after surgery (ERAS) pathway [16]. (See "Abdominal nerve block techniques", section on 'Transversus abdominis plane (TAP) blocks' and "Epidural and combined spinal-epidural anesthesia: Techniques".)

Open versus laparoscopic partial gastrectomy — The choice between an open surgical versus laparoscopic approach to partial gastric resection depends upon the indication for surgery, the experience of the operator, and the preferences of the surgeon and patient. As with most procedures performed laparoscopically, the operating surgeon should have sufficient experience with the open procedure and should be able to perform a comparable anatomic dissection and reconstruction using laparoscopic techniques, particularly when managing malignancies.

Laparoscopic partial gastrectomy has been described for many indications. A laparoscopic approach may be most feasible for limited gastric resections that require minimal dissection, such as with wedge or sleeve resection for benign indications or gastrointestinal stromal tumor [17]; however, the laparoscopic approach has also been used for resecting invasive cancers [18]. The feasibility and oncologic safety of laparoscopic partial gastrectomy for both early and locally advanced gastric cancer has been demonstrated by many randomized trials from Asia, and a few from Europe. (See "Laparoscopic gastrectomy for cancer", section on 'Eastern versus Western experience' and "Laparoscopic gastrectomy for cancer", section on 'Outcomes'.)

Incision and exposure — The patient should be positioned supine. For open gastrectomy, a midline abdominal approach is typically used. A self-retaining retractor helps to retract the liver and intestinal contents, facilitating exposure. (See "Incisions for open abdominal surgery", section on 'Midline incision'.)

The techniques of laparoscopic gastrectomy for cancer are discussed in detail elsewhere. (See "Laparoscopic gastrectomy for cancer", section on 'Surgical techniques'.)

Prior to initiating the dissection (open or laparoscopic), the abdominal cavity, including the peritoneal surfaces, should be thoroughly explored to evaluate for any metastatic disease. The extent of locoregional disease should also be assessed.

Extent of resection — Partial gastrectomy implies that only a part of the stomach is resected. The extent of resection depends on the location and size of the lesion, whether the lesion is benign or malignant, and for malignant lesions, whether an adequate proximal or distal margin can be achieved. When an adequate proximal gastric margin cannot be assured, a total gastrectomy is required.

Total gastrectomy refers to removal of the entire stomach, including the gastroesophageal junction and pylorus. Total gastrectomy is discussed elsewhere. (See "Total gastrectomy and gastrointestinal reconstruction".)

Optimal surgical margin — For patients undergoing potentially curative surgery for gastric malignancy, a tumor-free resection margin (R0) on pathologic examination is the goal of resection. A positive margin (R1) is associated with worse five-year survival (hazard ratio 2.06, 95% CI 1.61-2.65) [3].

To achieve an R0 resection, intraoperative frozen sections of the proximal and distal margins should be obtained in all patients undergoing potentially curative surgery. Based upon the results of these frozen sections, a wider excision may be necessary, as re-excision of a positive margin does improve the prognosis for some patients with gastric cancer [19].

Because gastric cancer, especially the diffuse type, has a propensity for intramural spread, the intraoperative frozen section may not be completely reliable [20]. Thus, a gross safety margin around the tumor is obtained to ensure negative final margins. The optimal gross margin of resection remains debated. Currently, the following has been proposed in Asian guidelines [2,21,22] and accepted by Western surgeons [12]:

●For early gastric cancer (T1) – A proximal margin of at least 2 cm.

●For non-early gastric cancer (T2 or above) – A proximal margin of at least 3 cm for tumors with an expansive growth pattern and at least 5 cm for tumors with an infiltrative growth pattern.

Margins for lymphoma and gastrointestinal stromal tumors (GISTs) need not be as extensive (1 to 2 cm), although there is no agreement on specific size of adequate margins. The use of intraoperative frozen section for these lesions is not well described.

Lymph node dissection — The Japanese classification defines the level of lymph node dissection (table 1) by the stations of lymph nodes removed for each procedure (eg, total gastrectomy, distal gastrectomy) (figure 7) [2]. We find it more practical to use a broader classification that defines the extent of lymph node dissection according to the relationship of the nodes to the segment of stomach to be removed, as follows:

●D0 – Refers to an incomplete D1 lymph node dissection or no formal lymph node dissection.

●D1 – Removal of lymph node basins directly related to the segment of stomach removed (ie, perigastric nodes). A D1 lymph node dissection is the minimal lymphadenectomy required of an oncologic gastric resection.

●D2 or D1+ – Removal of D1 lymph node basins and lymph node basins along major named neurovascular arcades supplying that region of the stomach (eg, celiac, left gastric, hepatic, and splenic arteries).

●D3 – Removal of D2 lymph node basins and para-aortic lymph nodes.

The extent of lymph node dissection needed during gastric resection for gastric adenocarcinoma is somewhat controversial. Treatment guidelines published by the National Comprehensive Cancer Network, Cancer Care Ontario, and European Society of Surgical Oncology recommend that D2 lymph node dissection is preferred over a lesser (D1) or greater (D3) dissection [12,13]. A D2 lymph node dissection is the standard approach to gastric cancer surgery in the East (eg, Japan, China, and Korea) [2,21,22]. However, in view of the higher reported rates of operative mortality in earlier randomized trials when more extensive dissection is performed, this recommendation should be tempered by where and by whom the operation is being performed (ie, D2 lymphadenectomy should be performed at high-volume centers by experienced oncologic surgeons). (See "Surgical management of invasive gastric cancer", section on 'Extent of lymph node dissection'.)

For patients with GISTs, no effort is made to perform an extended lymph node dissection because lymph node involvement is rare. For patients with neuroendocrine tumors, the extent of the lymph node dissection will depend on the type of gastric neuroendocrine tumor. (See "Staging, treatment, and post-treatment surveillance of non-metastatic, well-differentiated gastrointestinal tract neuroendocrine (carcinoid) tumors", section on 'Stomach'.)

Sentinel lymph node dissection — Although sentinel lymph node dissection is a well-established procedure for breast cancer and melanoma worldwide, its use in gastric cancer is limited to Eastern surgeons [23,24]. In Japan, sentinel lymph node dissection is indicated for cT1-2N0M0 patients undergoing gastrectomy [25]. If all sentinel nodes are negative, a function-preserving partial gastrectomy is performed without additional lymphadenectomy (termed laparoscopic sentinel node navigation surgery). If any of the sentinel nodes are positive, a standard radical gastrectomy (subtotal or total) with a D2 lymph node dissection is performed [26]. Surgeons should have pause before adopting this strategy in a lower volume Western practice, where case volumes, technical experience, and pathology experience might introduce suboptimal results [27].

Technical issues need to be resolved before sentinel lymph node dissection is accurate enough to be routinely applied [24,28]. The false negative rate was unexpectedly high (46 percent) in the initial trial of 440 patients (JCOG 0302) [29]. A subsequent trial performed by surgeons more experienced with the technique reported a much lower false negative rate of 7 percent [30]. A larger trial (SENORITA) of 550 patients with early gastric cancer reported similar rates and severity of complications following laparoscopic sentinel node navigation surgery versus laparoscopic standard gastrectomy with lymph node dissection; long-term oncologic outcomes are pending [31]. Proponents of laparoscopic sentinel node navigation surgery, which is built upon sentinel lymph node dissection, believe that it improves the patient's quality of life by preserving the stomach [32]. (See "Surgical management of invasive gastric cancer", section on 'Sentinel lymph node biopsy for early gastric cancer'.)

RESECTION TECHNIQUES — The term "partial gastrectomy" is broad and encompasses essentially any procedure that does not remove the entire stomach. Partial gastrectomy can be proximal or distal. Distal gastrectomy can be performed to remove only the antrum, the distal two-thirds of the stomach, the distal four-fifths, or nearly the entire stomach as a subtotal gastrectomy. Other types of gastrectomy include wedge resection, mucosal/sleeve resection, proximal gastrectomy, and pylorus-preserving segmental gastrectomy.

The type and extent of gastric resection is determined by the location, nature, and extent of disease (algorithm 1). Each technique has defined indications and specific, although sometimes overlapping, reconstructive options.

The options for partial gastric resection are listed. Each of these techniques is briefly reviewed below.

●Local excision/wedge resection

•Benign tumor excision

•Traumatic injury to the stomach

•Gastrointestinal stromal tumors amenable to wedge resection with appropriate 1 to 2 cm gross margins

●Sleeve (tube) gastrectomy

•Management of obesity (bariatric or metabolic surgery)

●Antrectomy/distal gastrectomy

•Malignant tumor in the distal (lower two-thirds) of the stomach

•Refractory peptic ulcer disease or ulcer disease associated with neuroendocrine tumors

•Traumatic injury

●Proximal gastrectomy (a type of function-preserving gastrectomy)

•Early gastric cancer of the proximal (upper one-third) of the stomach not amenable to endoscopic resection

•Traumatic injury

●Pylorus-preserving gastrectomy (a type of function-preserving gastrectomy)

•Early gastric cancer of the middle third of the stomach

●Subtotal gastrectomy

•Standard gastric resection for non-early gastric cancer (in lieu of total gastrectomy when adequate proximal margin can be achieved)

Local excision/wedge resection — The goal of wedge resection is to obtain an appropriate margin without significant narrowing of the stomach. Care must be taken near the gastroesophageal junction or the pylorus to avoid this problem. To perform local excision/wedge resection, the area of interest is identified, and a gastrointestinal stapler can be fired once across the stomach margin or twice to remove a triangular wedge of gastric tissue.

Sleeve gastrectomy — Sleeve gastrectomy is a type of partial gastrectomy in which the majority of the greater curvature of the stomach is removed using gastric staplers, creating a tubular stomach. It is used almost exclusively as a bariatric procedure. (See "Laparoscopic sleeve gastrectomy".)

Antrectomy/distal subtotal gastrectomy — Antrectomy is used to treat patients with refractory peptic ulcer disease, neuroendocrine tumors, or gastric adenocarcinoma. When performed for distal (lower two-thirds) gastric adenocarcinoma, antrectomy/distal gastrectomy includes resection of associated lymph node basins for adenocarcinoma. (See 'Lymph node dissection' above.)

To perform antrectomy/distal subtotal gastrectomy (figure 8):

●Identify the proximal resection margin. The incisura is generally recognized as the proximal extent of resection in an antrectomy. However, if needed, carry the proximal dissection superior to the incisura on the lesser curvature, and superior to the confluence of the gastroepiploic vessels on the greater curvature to obtain a sufficient margin. (See 'Optimal surgical margin' above.)

●Mobilize the greater omentum (figure 3) from the transverse colon to remove it with the specimen for tumor resection. The extent of omentectomy is determined by the proximal extent of the gastric resection. The omentum can be left in situ in the case of antrectomy for benign disease.

●Identify the pylorus. Ligate and divide the right gastric and gastroepiploic vessels at the pylorus.

●Skeletonize and transect the duodenum just distal to the pylorus using a linear stapler. Care should be taken to avoid injury to the structures of the portal triad.

●Some surgeons oversew the duodenal stump using a running, permanent suture (eg, 3-0 Prolene) on a noncutting needle.

●Carry the dissection cephalad along the greater and lesser curves of the stomach. For adenocarcinoma, the lesser omentum (gastrohepatic ligament) should be harvested with the specimen provided there is not a variant hepatic artery (figure 6) coursing through this region. For patients with benign disease, harvest the greater curve of the stomach just outside the gastroepiploic arcade. In some partial gastrectomies, the left gastric pedicle needs to be divided to achieve adequate proximal margin.

●For a subtotal gastrectomy, the distal left gastroepiploic arcade and some of the short gastric vessels will need to be ligated.

●Transect at the proximal stomach margin using a linear gastrointestinal stapler.

●For patients requiring a D2 nodal dissection, send the named nodal basins along the vascular arcades of the stomach as separate, labeled specimens for pathologic examination.

Function-preserving partial gastrectomy — Function-preserving techniques for partial gastrectomy have been introduced by Japanese surgeons as a means to limit or avoid syndromes that result from altered anatomy and/or physiology following traditional methods of gastric resection and reconstruction (ie, postgastrectomy syndromes). However, it is only performed in highly specialized centers in East Asian countries and is not considered a standard operation in the rest of the world. Surgeons should not attempt to perform these operations without prior in-depth knowledge and training.

Function-preserving techniques are only applicable to early gastric cancers (cT1) that are either not feasible for endoscopic resection or are not completely removed by endoscopic resection. These gastrectomies are performed with a D1 or D1+ lymphadenectomy. Non-early gastric cancers (cT2-4 or N+) should be treated with a standard gastrectomy, which removes at least two-thirds of the stomach, along with a D2 node dissection that is standard in the Japanese literature [2].

The most frequently performed function-sparing resection procedures in the world are proximal gastrectomy for carcinoma of the upper stomach and pylorus-sparing gastrectomy (PPG) for carcinoma of the middle third of the stomach [33]. Neither is frequently performed in Western countries, where most gastric cancers are diagnosed in an advanced stage.

Proximal gastrectomy — Proximal gastrectomy resects the cardia and upper portion of the corpus, but more than half of the stomach remains (figure 9). It is an option for early gastric cancer in the proximal (upper third) of the stomach that does not invade the gastroesophageal junction. Studies from the East have demonstrated its oncologic safety compared with standard gastrectomy with D2 lymphadenectomy [34,35].

The alternative to proximal gastrectomy is a total gastrectomy (figure 10). Compared with total gastrectomy, proximal gastrectomy may have nutritional benefits [35,36] but a higher incidence of bile reflux and anastomotic stenosis [34,35,37]. The exact balance between the advantages and disadvantages of proximal gastrectomy lies in its reconstruction [38].

●Esophagogastrostomy – Esophagogastrostomy is the simplest and most physiologic reconstruction after proximal gastrectomy, which also makes it easy to surveil the gastric remnant endoscopically. The major disadvantage of esophagogastrostomy is bile reflux. Several anti-reflux modifications have been proposed, including gastric tube [39], double-flap reconstruction [40,41], and side overlap esophagogastrostomy with fundoplication by Yamashita [42,43].

●Jejunal interposition – Jejunal interposition positions an 8 to 15 cm long pedicled loop of proximal jejunum between the esophagus and the gastric remnant. Compared with esophagogastrostomy, jejunal interposition decreases reflux but increases operative time and length of hospital stay [44]. Additionally, residual food is another problem for jejunal interposition [38].

●Double-tract reconstruction – During double-tract reconstruction after proximal gastrectomy, the jejunum is divided approximately 15 cm distal to the ligament of Treitz. The distal limb is anastomosed to the esophagus. A side-to-side gastrojejunostomy with the remnant stomach is performed 15 cm below the esophagojejunostomy. Finally a jejunojejunostomy is performed approximately 25 cm below the gastrojejunostomy to restore bowel continuity (figure 11). In a meta-analysis of one trial and 13 nonrandomized studies comparing proximal gastrectomy with double-tract reconstruction with total gastrectomy, the former was associated with superior nutritional outcomes, but oncologic equivalency could not be assessed due to potential selection bias against total gastrectomy [45]. The randomized trial reported very few tumor recurrences [46]. The KLASS-05 trial also found laparoscopic proximal gastrectomy with double-tract reconstruction and laparoscopic gastrectomy comparable in perioperative outcomes [47]. Long-term outcomes are not yet reported.

Pylorus-preserving gastrectomy — PPG, which resects a portion of the stomach but leaves the pylorus intact (figure 12), was originally developed as a treatment approach for gastric ulcer surgery as a means to improve quality of life and avoid postgastrectomy syndromes. This technique has been championed for patients with early gastric cancer in the middle third of the stomach with the tumor >4 cm from the pylorus [2].

A 2020 systematic review and meta-analysis of 21 nonrandomized comparative studies found oncologic equivalence between PPG and distal gastrectomy for early gastric cancer [48]. The KLASS-04 trial, which directly compared the two, has not reported long-term outcomes [49]. The safety and appropriateness of this surgery has not been studied in low-incidence populations for early gastric cancer, such as in North America.

Pylorus preservation can reduce dumping syndrome and bile regurgitation, which improves nutritional status and quality of life [33,48]. It also increases the risk of delayed gastric emptying, which can be countered by preserving the pyloric branches of the vagal nerve [49]. (See 'Preservation of the vagus nerves' below.)

To perform PPG:

●Following omentectomy, harvest the lymph nodes along the right gastroepiploic vessels.

●Divide the right gastroepiploic arcade distal to the infrapyloric artery and carry the dissection along the greater curve of the stomach.

●Harvest the left gastroepiploic vessels with the station 4sb lymph nodes.

●Harvest the lymph nodes of the lesser curve and preserve the hepatic and pyloric branches of the vagus nerves and right gastric vessels.

●Remove the distal stomach with station 7, 8, 9, and 11p lymph nodes, preserving 3 cm of antrum and the pylorus.

●Harvest the left gastric vessels and transect the stomach proximally with a 2 cm margin.

●Perform an end-to-end anastomosis of the proximal to distal gastric remnants using a full-thickness single-layer suture (eg, Gambee suture (figure 13)).

Preservation of the vagus nerves — Traditional resection techniques for gastric adenocarcinoma have not emphasized preservation of the vagus nerves, but this practice is supported by Eastern surgeons who treat patients with early gastric cancer and can be performed in conjunction with a D1 or D2 lymphadenectomy. Preserving the hepatic branch of the anterior vagus nerve and celiac branch of the posterior vagus nerve decreases the incidence of postoperative diarrhea and postgastrectomy gallstone formation [50]. (See "Total gastrectomy and gastrointestinal reconstruction", section on 'Vagus nerve preservation'.)

Subtotal gastrectomy — For patients with non-early gastric cancer (cT2-4 or N+), the standard gastric resection is either a subtotal gastrectomy or a total gastrectomy, both with a D2 lymphadenectomy. The choice is dependent on whether an adequate proximal gastric margin is achievable with a subtotal gastrectomy; if not, total gastrectomy is performed. (See 'Optimal surgical margin' above.)

From an oncologic standpoint, a total gastrectomy has no advantage over subtotal gastrectomy for distal tumor when an adequate proximal margin can be achieved [51]. Whether subtotal gastrectomy reduces morbidities compared with total gastrectomy is uncertain. A meta-analysis of six trials found that subtotal gastrectomy reduced anastomotic leaks, but not overall morbidities compared with total gastrectomy [52]. A second meta-analysis of four trials and seven nonrandomized comparative studies associated subtotal gastrectomy with lower rate of overall postoperative complications, anastomosis leakage, wound complications, peritoneal abscesses, and mortality [53]. A long-term study found that subtotal gastrectomy improves quality of life in the first five years after surgery [54]. After that, any advantage over total gastrectomy diminishes.

GASTROINTESTINAL RECONSTRUCTION — Reconstructive procedures can be broadly thought of as those that preserve duodenal continuity, those that preserve jejunal continuity, those that preserve both, and those that incorporate some form of pouch reconstruction. Duodenal continuity is important for preventing loss of fat-soluble vitamins, while jejunal continuity is important for preventing retrograde flow of jejunal contents, which can occur because transection of the jejunum interrupts the electrical activity normally initiated by the duodenal pacemaker, thus impairing antegrade peristalsis.

Ideally, gastric reconstruction would avoid adverse consequences related to the loss of stomach tissue and function (ie, postgastrectomy syndromes), but each type of reconstruction is associated with, at a minimum, some degree of dumping (early or late) since the pylorus is typically removed (except for pylorus-preserving gastrectomy). The characteristics and postgastrectomy syndromes associated with each of these reconstructions are given in the table (table 4). (See "Postgastrectomy complications".)

The most common gastric reconstructive procedures following partial (typically distal) gastrectomy are the Billroth I, Billroth II, and Roux-en-Y reconstructions. Roux-en-Y reconstruction is most performed worldwide, with Billroth II being an alternative. Billroth I is primarily performed in Asia [33].

Billroth I — The Billroth I reconstruction (figure 14) preserves duodenal and jejunal continuity by anastomosing the remnant stomach to the duodenal stump in a primary end-to-end fashion. Billroth I reconstruction is the preferred method of reconstruction when the proximal gastric remnant and the duodenal stump can be approximated without tension, which is generally possible only after antrectomy.

The most common postgastrectomy syndrome (table 4) associated with Billroth I reconstruction is reflux of biliary contents retrograde into the stomach, causing alkaline gastritis. If the residual gastric remnant is small or nonfunctional, there will likely be some degree of dumping. (See "Postgastrectomy complications".)

Billroth II — The Billroth II reconstruction (figure 14) anastomoses the remnant stomach to the proximal jejunum in an end-to-side fashion. This reconstruction preserves jejunal but not duodenal continuity and is used when a Billroth I reconstruction is not possible, such as with more extended distal gastrectomy (ie, more than the antrum is resected). The Billroth II reconstruction has an afferent limb from the duodenum and an efferent limb extending distally. For a Billroth II reconstruction, the jejunal anastomosis can be performed in an antecolic or retrocolic, isoperistaltic, or antiperistaltic fashion (figure 15). Functional differences between these have not been documented. Modification to the original Billroth II reconstruction include adding a Braun enteroenterostomy (figure 16) to divert a significant amount of bile from the remnant stomach [55].

Following Billroth II reconstruction, patients can expect to suffer from alkaline reflux gastritis and some dumping (table 4), but unlike Billroth I reconstruction, Billroth II also leads to some degree of malabsorption, particularly of fat-soluble vitamins, because of loss of duodenal continuity. (See "Postgastrectomy complications".)

Roux-en-Y gastrojejunostomy — The Roux-en-Y gastrojejunostomy anastomoses the remnant stomach to an isoperistaltic roux limb of jejunum (figure 8). The proximal jejunum is anastomosed to the distal Roux limb in an end-to-side fashion. The optimal length of the afferent limb appears to be approximately 40 cm [56,57]. A shorter limb would increase the risk of bile (alkaline) reflux gastritis, and longer limb may increase the risk of Roux stasis syndrome. An "uncut" version of the Roux-en-Y reconstruction may reduce the incidence of both bile reflux and Roux-stasis syndrome [58-60]. Another modification to the Roux-en-Y reconstruction is double-tract reconstruction described above. (See 'Proximal gastrectomy' above.)

Roux-en-Y gastrojejunostomy can be used in the same situations as a Billroth II, although it does not preserve duodenal or jejunal continuity. Roux-en-Y reconstruction diverts the bilious drainage away from the gastric remnant. Although patients suffer from lesser degrees of reflux than seen in Billroth reconstruction (I or II), patients report dumping to a greater or lesser extent [61]. However, Roux-en-Y reconstruction may lead to gastric atony, and this, together with the adverse effect of jejunal transection, contributes to a syndrome of abdominal pain and vomiting known as the "Roux syndrome" or "Roux stasis syndrome." Patients with severe Roux stasis syndrome may require completion gastrectomy. (See "Postgastrectomy complications".)

Choice of reconstruction — Many factors influence the choice of reconstruction after gastrectomy. For most partial gastrectomy patients, we suggest a primary Roux-en-Y reconstruction. Based upon randomized trials, Roux-en-Y reconstruction appears to be tolerated better overall and leads to a better quality of life compared with Billroth reconstruction (Billroth I or Billroth II).

Whether to preferentially perform a Roux-en-Y in patients whose anatomy supports a Billroth I or Billroth II, or convert to a Roux-en-Y only if complications occur, remains controversial.

●In a 2022 systematic review and meta-analysis of 10 randomized trials comparing at least two of the reconstruction techniques following distal gastrectomy for cancer, all five major techniques (Billroth I, Billroth II, Billroth II with Braun, Roux-en-Y reconstruction, and uncut Roux-en-Y) were considered safe, with comparable anastomotic leak, anastomotic stricture, and overall morbidity rates [62]. At 12 months, Roux-en-Y reconstruction is associated with a reduced risk of remnant gastritis and a trend toward a reduced risk of bile reflux and esophagitis [62]. Another meta-analysis of 12 randomized trials also concluded that Roux-en-Y reconstruction reduces remnant gastritis compared with either Billroth reconstruction, but it is also the most technically complex to perform [63].

●A Cochrane review of eight randomized trials comparing Billroth I with Roux-en-Y reconstruction after distal gastrectomy for cancer found a lower incidence of bile reflux with Roux-en-Y but lower morbidity and shorter hospital stay with Billroth I reconstruction. However, the overall quality-of-life scores did not differ between the two techniques [64]. All of the studies included in this review were from Asian countries. The applicability of these data to Western patients may be limited. Billroth I surgeries are limited to small, early, and quite distal lesions, which would be rare entities in the North American and European patient populations. Furthermore, Billroth I surgeries were done commonly in the ulcer surgery era but are rarely needed for benign gastric surgery currently. Thus, fewer Western surgeons may have real case experience with this procedure.

●In a retrospective comparative study of 1300 distal gastrectomies performed for cancer, Billroth I reconstruction was associated with the least amount of weight and nutritional loss at one-year follow-up [65]. Compared with Billroth I, Billroth II was associated with decreased body mass index and low protein and albumin, whereas Roux-en-Y was associated with decreased body mass index and low cholesterol. Other factors varied between the groups in this study, including use of open versus laparoscopic approach, extent of lymph node dissection, and final tumor stage. Thus, the results may not purely be a reflection of surgical choice but a composite of tumor, surgical, and patient factors.

●In a retrospective study that followed 459 patients for five years after distal gastrectomy for cancer, Roux-en-Y reconstruction was associated with lower incidence of bile reflux and gastritis, and higher incidence of gallstone formation than Billroth I reconstruction [66]. The incidence of gastric residue was more common after Roux-en-Y reconstruction at one and two years, but the difference became less significant at five years.

POSTOPERATIVE CARE AND FOLLOW-UP — Enhanced recovery after surgery (ERAS), also known as fast-track protocols, has been used for selected patients undergoing gastric surgery [67,68]. Patients with American Society of Anesthesiology (ASA) grade >2 malnutrition are not candidates. The elements of a fast-track protocol are reviewed elsewhere. (See "Anesthetic management for enhanced recovery after major noncardiac surgery (ERAS)".)

Nasogastric tube decompression — Routine nasogastric decompression is not necessary, even for patients undergoing esophageal or gastric surgery. For most patients with a nasogastric tube, it can be discontinued in the recovery room or on the first day postoperatively [16]. If a nasogastric tube becomes dislodged or has fallen out, it should not be replaced unless that patient has symptoms.

Some patients may have prolonged spasm or edema of the gastrojejunal or jejunojejunal anastomoses leading to nausea and emesis. If the gastrointestinal decompression has been discontinued, a nasogastric tube may need to be replaced.

When nasogastric replacement is needed following proximal subtotal gastrectomy, we prefer placement under fluoroscopy to avoid any risk of disrupting the proximal anastomosis; for distal gastrectomy, fluoroscopic imaging may not be necessary.

Perioperative nutritional support — Prior to gastric resection, patients can have poor oral intake due to nausea, vomiting, or early satiety and may be malnourished, increasing the risk for surgical complications. After gastric surgery, some patients may not be able to resume oral intake due to spasm or edema of the gastrojejunal or jejunojejunal anastomoses. In the setting of preoperative malnutrition, perioperative nutritional support should be provided, which can be initiated via total parenteral nutrition (TPN) or a feeding jejunostomy placed at the time of the gastric resection [69].

If a feeding jejunostomy tube is to be used, it should be placed into the jejunum approximately 30 to 40 cm beyond the most distal anastomosis. The tube should be flushed twice daily for the first 24 hours, and thereafter, it can be used to provide enteral support. Enteral feedings can be initiated as a dilute solution at approximately 10 mL per hour and increased to the target rate.

There may be a role for preoperative nutritional support if the patient's nutritional indices are severely depressed. (See "Overview of perioperative nutrition support", section on 'Preoperative nutrition support'.)

Postgastrectomy diet — The extent of alteration of oral intake will be determined by the size of the gastric remnant and the need to conservatively manage postgastrectomy syndromes. Small frequent meals, high in protein and inclusive of fat, should be consumed approximately six times per day. Liquids may need to be taken separately from solids. Meals high in simple carbohydrates can contribute to dumping syndrome and may need to be avoided. The patient should be followed closely, at least initially, by a dietician experienced with managing patients who have undergone this procedure.

Vitamin and mineral supplementation may also be necessary (see "Bariatric surgery: Postoperative nutritional management"):

●Patients who have undergone subtotal gastrectomy will need vitamin B12 supplementation. (See "Clinical manifestations and diagnosis of vitamin B12 and folate deficiency".)

●Patients who have undergone reconstructive procedures that bypass the duodenum (eg, Billroth II, Roux-en-Y) may require supplementation of fat-soluble vitamins (A, D, E, K). (See "Overview of vitamin A" and "Overview of vitamin D" and "Overview of vitamin E" and "Overview of vitamin K".)

●Calcium and iron should also be supplemented. (See "Treatment of iron deficiency anemia in adults" and "Treatment of hypocalcemia".)

Follow-up — Following partial gastric resection, the patient should follow up to evaluate the incision(s) and overall recovery and periodically thereafter to monitor weight, nutritional status, and the presence of any symptoms that may indicate the development of complications related to the gastric resection or reconstruction.

Symptoms may include weight loss, fever, abdominal pain, early satiety, persistent vomiting, reflux symptoms, hematemesis, and/or unexplained anemia. Further abdominal imaging or endoscopic evaluation may be needed. (See "Postgastrectomy complications" and "Endoscopic retrograde cholangiopancreatography (ERCP) after Billroth II reconstruction" and "ERCP in patients with Roux-en-Y anatomy".)

Following gastric resection for malignancy, scheduled follow-up is suggested to detect clinical symptoms of recurrence, which occurs most commonly in the first two to three years. However, it is important to note that most patients undergoing partial gastrectomy for adenocarcinoma do not fail surgical treatment due to gastric mucosal recurrence but rather develop nodal disease or distant metastases [70]. These issues are discussed in detail elsewhere. (See "Surgical management of invasive gastric cancer", section on 'Post-treatment surveillance'.)

PERIOPERATIVE MORTALITY AND MORBIDITIES

Mortality — Perioperative mortality following partial gastric resection is low, even among appropriately selected candidates with malignant tumor. In series comparing open with laparoscopic gastric resection, no significant differences have been found, and reported perioperative mortality rates in contemporary series are 1 to 2 percent [71,72].

Morbidities — In similar contemporary series, the morbidity rate varies from 18 to 26 percent, depending on the inclusion criteria and length of follow-up [71,72]. Complications following partial gastrectomy can be anatomic, related to the extent of gastric resection and the type of reconstruction, or physiologic, related to the loss of function in the section of stomach removed (table 4). Postgastrectomy complications are discussed in detail separately. (See "Postgastrectomy complications".)

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: Gastric surgery for cancer".)

SUMMARY AND RECOMMENDATIONS

●Indications – Partial gastric resection is used to treat most cases of benign gastric disease for which resection is indicated (eg, ulcer disease, benign tumor, traumatic injury); malignant gastric tumors, such as adenocarcinoma, where sufficient margins can be achieved; in select cases of gastrointestinal stromal tumor (GIST); some neuroendocrine tumors; and complications related to treatment of lymphoma. (See 'Indications' above.)

●Surgical techniques – Partial gastrectomy procedures include wedge resection, sleeve resection, antrectomy/distal gastrectomy, subtotal gastrectomy, proximal gastrectomy, and pylorus-preserving gastrectomy. The extent of gastric resection and type of reconstruction chosen is determined by the location, nature, and extent of disease and impacts the nature of perioperative and later complications, particularly the development of postgastrectomy syndromes (algorithm 1). (See 'Resection techniques' above.)

•Margins – For patients undergoing partial gastrectomy for non-early gastric adenocarcinoma, we obtain a margin of at least 3 cm for tumors with an expansive growth pattern and at least 5 cm for tumors with an infiltrative growth pattern. A proximal margin of 2 cm is sufficient for early gastric cancer. Intraoperative frozen sections of the proximal and distal margins should be obtained to determine if a wider excision is necessary. (See 'Optimal surgical margin' above.)

•Reconstruction – Several reconstructions are used to restore gastrointestinal continuity following partial gastrectomy. The most common are the Billroth I, Billroth II, and Roux-en-Y reconstructions, with the choice between these depending upon the remnant anatomy available for reconstruction. For patients who have undergone partial gastrectomy, we suggest Roux-en-Y reconstruction over Billroth reconstruction (Billroth I or Billroth II) (Grade 2C). (See 'Gastrointestinal reconstruction' above.)

•Function-preserving alternatives – Function-preserving techniques for partial gastrectomy have been introduced by Japanese surgeons to limit or avoid postgastrectomy syndromes in patients. These include proximal gastrectomy for early gastric cancers in the upper stomach and pylorus-preserving gastrectomy for early gastric cancers in the middle third of the stomach. However, these operations should only be performed by experienced surgeons in select patients with early gastric cancer. (See 'Function-preserving partial gastrectomy' above.)

•Open versus minimally invasive surgery – A laparoscopic approach may be most feasible for limited gastric resections that require minimal dissection, such as wedge or sleeve resection for benign indications or gastrointestinal stromal tumor. At high-volume centers in Asia and Europe, the feasibility and oncologic safety of laparoscopic partial gastrectomy for both early and locally advanced gastric cancer has been demonstrated by many randomized trials. (See 'Open versus laparoscopic partial gastrectomy' above and "Laparoscopic gastrectomy for cancer".)

●Postoperative care – Nasogastric tube, if placed, can be removed on the day of or after the surgery. Patients should be started on a postgastrectomy diet (small, frequent meals) and vitamin supplements. Those who are malnourished preoperatively may require nutritional supplement with parenteral or jejunostomy feeding. Following partial gastrectomy for malignancy, scheduled follow-up is suggested to evaluate for recurrence. (See 'Follow-up' above and "Surgical management of invasive gastric cancer", section on 'Post-treatment surveillance'.)

●Outcomes – In contemporary series, partial gastrectomy carries a mortality rate of 1 to 2 percent and a morbidity rate of 18 to 26 percent. Complications following partial gastrectomy can be related to anatomic or physiologic alterations. The most concerning postoperative complication is anastomotic leak. The nature and severity of postgastrectomy syndromes depend upon the extent of gastric resection and the type of gastric reconstruction (table 4). (See 'Morbidities' above and "Postgastrectomy complications".)

ACKNOWLEDGMENT — The UpToDate editorial staff acknowledges Debrah Wirtzfeld, MD, MSc, FRCSC, FACS, who contributed to an earlier version of this topic review.