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CHAPTER 19GastrectomyEMBRYOLOGY The anatomic relationships of the stomach in theadult can be easily understood by the embryologic development.The stomach is derived from the foregut. It is initially a fusiformdilatation present in the median plane that subsequently under-goes two rotations. A 90-degree rotation occurs along the longitu-dinal axis of the stomach such that the left side forms theanterior surface, and the right side the posterior surface. Theoriginal ventral border forms the lesser curvature, and the fastergrowing dorsal border develops into the greater curvature. Thisrotation results in the left vagus innervating the anterior sur-face and the right vagus innervating the posterior surface ofthe stomach. A further rotation occurs in the anteroposterioraxis, allowing the stomach to assume the transverse positionin relation to the long axis of the body. The primitive lessersac (omental bursa) is derived from resorption of the rightside of the thick dorsal mesogastrium. The lesser sac islocated behind the stomach in adults, and this positionresults from expansion of the bursa, lengthening of the dor-sal mesogastrium, and rotation of the stomach. The lessersac communicates with the general peritoneal cavitythrough the epiploic foramen (foramen of Winslow).ANATOMY The stomach is the dilated portion of theforegut between the esophagus and the duodenum. It isusually J shaped and located in the left upper quadrantand epigastrium, and its distal pa rt can extend to the levelof the umbilicus. The stomach is divided into a fundus,body, antrum, and pyloius. The fundus is th at par t of thestomach that lies above the level of the gastroesophageal

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114 Operative Surgery Manualjunction. The body extends from the fundus to the incisura angularis. Theincisura angularis is most clearly seen during gastroscopy. The pyloricportion of the stomach consists of the antrum, which extends from theincisura angularis to the proximal limit of the pylorus. The pyloric canalis surrounded by a thick muscular wall that forms the pyloric sphincter.The pyloric canal is approximately 2.5 cm long, and the pyloroduodenaljunction is identified by presence of the prepyloric vein (vein of Mayo),which crosses its anterior surface.

The stomach possesses a lesser and a greater curvature. The lessercurvature extends from the right side of the esophagus to the level of thepylorus, and to it is attached the lesser omentum (gastrohepatic ligament).Conversely, the greater curvature extends from the left of the esophagus,around the fundus, and to the right side of the pylorus. The upper part ofthe greater curvature gives attachment to the gastrosplenic ligamentcontaining the short gastric vessels, whereas the greater omentumextends from the lower portion of the greater curvature. The posteriorrelation of the stomach, also known as the bed of the stomach, is formedby the lesser sac. Posteriorly, the relations are the diaphragm above and,from right to left, the pancreas, the splenic artery, the spleen, the leftkidney, and the adjacent adrenal gland.

Because the stomach is derived from the foregut, its blood supply orig-inates from the branches of the foregut artery, the celiac axis. The left gas-tric artery that arises from the celiac axis and the right gastric artery thatarises from the hepatic artery supply the lesser curvature and the adjacentsurfaces. The greater curvature and the adjacent portion of the stomachare supplied by the left gastroepiploic artery, which arises from the splenicartery, and from the right gastroepiploic artery, which arises from the gas-troduodenal branch of the hepatic artery. The short gastric arteries arisefrom the splenic artery at the hilum, pass within the gastrosplenic liga-ment, and supply the fundus. The venous drainage of the stomach flowsthrough the portal vein. The right and the left gastric veins enter theportal vein directly, the right gastroepiploic vein drains into the superiormesenteric vein, and the left gastroepiploic vein and the short gastricveins join the splenic vein. The lymphatic drainage follows the arteries anddrains ultimately into the celiac lymph nodes.The nerve supply of the stomach is derived from both the right andthe left vagus nerve and the celiac plexus of sympathetic fibers that arisefrom the fifth, sixth, seventh, and eighth thoracic segments of the spinalcord. Because of the rotation of the stomach during embryonic develop-ment, the left vagus lies anterior to the esophagus, whereas the rightvagus lies posterior. The anterior vagus enters the abdomen anterior to theesophagus and gives off hepatic branches that travel in the lesser omentumto supply the liver and the gallbladder and a branch through the pyloricantrum. The anterior vagus nerve continues along the lesser omentum as


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CHAPTER 19:Gastrectomy 115the nerve of Latarjet and terminates approximately 5 to 7 cm proximalto the pylorus in several branches, described as the crows foot. The pos-terior (right) vagus nerve also lies between the leaves of the lesser omen-tum and follows a course along the lesser curvature posterior to theanterior vagus nerve as the nerve of Latarjet. In 90%of the cases, the pos-terior vagus nerve gives rise to t he nerve of Grassi, which originates at thelevel of the gastroesophageal junction and supplies the gastric fundus.

gastrectomy

Transectionof jejunum if a-- Roux-en-Y isto be created

FIGURE 19-1 The various levels of transection of the stomach needed to pelform atotal, subtotal, or distal gastrectomy. The level of jejunal transection needed to con-struct a Roux-en-Y ejunal limb isshown.


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116 Operative Surgery ManualHowever, in up to 20% of cases, the nerve of Grassi may actually originateabove the hiatus. When performing truncal vagotomy it is important toidentify and divide this branch to minimize the incidence of recurrentulceration.

A total, subtotal, or distal gastrectomy is performed, depending on thelocation of the tumor and whether an adequate en bloc lymphadenectomycan be performed (Fig. 19-1).PREOPERATIVE PREPARATION Tissue diagnosis must be obtained, and theextent of the malignant disease, particularly extension in the esophagus,is determined with preoperative upper gastrointestinal endoscopy. Basiclaboratory tests are obtained. Computed tomography of the abdomen,pelvis, and chest is performed to completely stage the disease. If there iscardiac history, a preoperative stress echo or Persantine thallium scan isobtained to assess the ejection fraction and cardiac wall motion. For aproximal tumor with extension into the esophagus, the thoracic cavitymay need to be accessed; therefore, pulmonary function tests are obtained.If a computed tomography scan of the abdomen suggests extension of thedisease to the transverse colon, a mechanical bowel preparation isperformed, because bowel resection may be necessary.

RADICAL TOTAL GASTRECTOMYThis procedure is most commonly performed for malignant diseases of thestomach.

Operative ProcedurePOSlTlON The patient is placed in the supine position. If there is likeli-hood of performing a thoracoabdominal incision, the patients left side iselevated with a wedge.A nasogastric tube and Foley catheter are inserted,and preoperative prophylactic antibiotics are administered.INCISION Adequate exposure can be obtained with a long midline incision.If necessary, an oblique extension into the left chest wall can be performedto improve exposure of the distal esophagus in the left thoracic cavity.EXPOSURE AND OPERATIVE TECHNIQUE After entering the abdominal cavity,the operators first step involves assessing whether the disease is curablesurgically by evaluating the presence of liver metastasis, peritoneal


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CHAPTER 19:Gastrectomy 117implants (particularly those that are outside th e confines of the resectionsuch as in the pelvis and diaphragm), and para-aortic lymph nodes. In thepresence of incurable disease, palliative gastrectomy should be consideredif the patient is symptomatic from the tumor.

The mobility of the spleen is assessed because subsequent medialdisplacement of the organ facilitates dissection of th e short gastric vessels.Any obvious adhesions are carefully divided to prevent traction injury tothe splenic capsule. The greater omentum is lifted and separated from thetransverse colon along the avascular plane and carefully dissected freefrom the transverse mesocolon up to the level of the pancreas. As thegreater omentum is retracted superiorly, th e right gastroepiploic branchof the gastroduodenal artery and the accompanying vein are encounteredadjacent to the head of the pancreas. These vessels are carefully dissected,divided, and ligated. The perigastric tissue in the region of the pylorus isdissected superiorly to include the subpyloric nodes within the specimen.Multiple small vessels are encountered adjacent to the duodenum. Thesevessels are serially clamped with fine hemostats, divided, and ligated with3-0 silk sutures. The proximal greater curvature of the stomach is mobilizedby dividing the left gastroepiploic artery. To facilitate the dissections of theshort gastric vessels, the gastrosplenic ligament can be brought into view bydisplacing the spleen medially and packing the splenic bed with moist lappads. This has the added benefit of avoiding traction on the spleen, thusavoiding inadvertent injury. The short gastric vessels are individually iso-lated, clamped, and ligated with 2-0 silk sutures. On the gastric side the ves-sels are further secured with 3-0 silk transfurion suture ligatures.

Attention is now directed toward mobilizing the esophagus. First, theleft triangular ligament of the liver is divided with electrocautery, thusallowing the left lateral lobe to be retracted. This maneuver exposes theesophageal hiatus. The peritoneal reflection over the hiatus is opened toexpose the two diaphragmatic crura. With careful blunt digital dissection,the esophagus is encircled and a Penrose drain is placed for traction. Theleft hand is passed behind the esophagus and the esophagophrenic ligamentis divided, thus completing the mobilization of the fundus and greater cur-vature of the stomach. The distal esophagus within the posterior medi-astinum is carefully mobilized. The two vagi are identified and dividedbetween hemoclips. The lesser omentum is divided to expose the celiac axisand its major branches. The left gastric artery is identified near its originand divided after ensuring that the left hepatic artery does not originatefrom the left gastric artery. The peritoneum over the porta hepatis is dis-sected to identlfy the right gastric artery, which is clamped, divided, and lig-ated. After the duodenum is mobilized with a Kocher maneuver, the firstpart of the duodenum is dissected from the head of the pancreas and tran-sected with the GIA-60 linear stapler. This allows the stomach to be ele-vated and any posterior congenital adhesions to be divided.


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118 Operative Surgery ManualNormally it is not necessary to resect the spleen during the total gas-

trectomy unless bulky lymph nodes are encountered in the splenic hilum,in which case the spleen is removed en bloc. If the spleen is to be removed,it is drawn medially, and the splenocolic, splenorenal, and phrenosplenicligaments are divided sharply with electrocautery. This has the addedbenefit of allowing assessment of the tail of the pancreas. If the tail of thepancreas is grossly involved with tumor, it is mobilized by dissecting in theretropancreatic space and is transected proximal to the area of involve-ment with the use of a TA-55 tapler. At this point the specimen should beleft attached solely at the esophageal end. A right-angle bowel clamp isplaced over the distal esophagus. Two stay sutures are placed in theesophageal wall just proximal to the clamp using 0-0 silk. The esophagusis divided, and the specimen is sent to the pathologist to perform frozensection analysis of both the distal and proximal margins.Lymphadenectomy is performed by skeletonizing the celiac, splenic,and hepatic arteries. About 15 to 20 cm from the duodenojejunal flexure,the jejunum is divided with a GIA-60 linear stapler. The mesentery isdivided to allow the distal aspect of jejunum to reach the esophagus with-out tension. If further length of jejunum is required, the peritoneal liningof the mesentery is incised in several directions. A 2- o 4-cm opening ismade in the avascular segment of the transverse mesocolon, and the dis-tal jejunal loop is passed through the defect toward the esophagus. Theesophagojejunal anastomosis can be either hand sewn or constructed withthe EEA stapling device.

For a hand-sewn end-to-side anastomosis, the outer posterior layer ofinterrupted Lembert sutures using 3-0 silk is placed between the esopha-gus and the jejunum. The adjacent antimesenteric border of the jejunumis opened with electrocautery. An inner full-thickness layer of interrupted3-0 silk sutures is placed. Finally, the outer anterior layer of interruptedseromuscular Lembert sutures using 2-0 silk is placed to complete theanastomosis.

If a stapled anastomosis is being constructed, the transected esopha-gus is gently dilated either digitally or with the 25 Fr sizer provided withthe stapling device.A purse-string suture is placed around the esophagususing a 3-0 polypropylene monofilament suture. The anvil of the EEAstapler is placed in the esophagus, and the purse-string suture is tied downsnugly. Next, the staple line at the end of the distal jejunal limb is excisedto allow insertion of the EEA stapler. The EEA stapling instrumentis opened to advance the central rod through an antimesenteric stabwound located approximately 3 to 4 m from the end of the jejunal limb(Fig. 19-2A). The anvil is engaged to the central rod; the EEA s closed andthen fired. The EEA s again opened and gently removed. The two tissuedoughnuts are inspected to ensure that they are complete. The anastomo-sis is inspected for hemostasis, and the jejunum is closed with a TA-55


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CHAPTER 19:Gastrectomy 119

FIGURE 19-2 Construction of a stapled end-to-side esophagojejunal anastomosis.A, The anvil is passed into the esophagus and the purse-string suture is tied. B, Thecompleted end-to-side esophagojejunal anastomosis.


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120 Operative Surgery Manualstapler (Fig. 19-2B).The anastomosis is tested by having the anesthesiol-ogist inject methylene blue through the nasogastric tube while gentlyoccluding the small bowel. The areas of leaks are reinforced with inter-rupted 3-0 silk sutures. The anastomosis is secured anteriorly with a sec-ond layer of seromuscular suture using 3-0 silk sutures. The nasogastrictube is passed beyond the anastomosis.

A side-to-side jejunojejunostomy is constructed approximately 50 cmdistal to the esophagojejunostomy.To prevent internal herniation, defectsin the transverse mesocolon are closed. At a convenient place distal to thisjejunojejunostomy, a feeding jejunostomy catheter is placed. A drain isplaced in the region of the transected duodenum and close to the pancreasif it has been transected.CLOSURE The midline incision is closed in a standard fashion by approx-imating the linea alba with continuous 1-0 polypropylene monofilamentsutures. The skin is approximated with staples after the subcutaneous tis-sue has been irrigated and hemostasis achieved.

RADICAL SUBTOTAL GASTRECTOMYFor small cancers limited to the distal antrum, the patient can be offeredradical distal or subtotal gastrectomy. At initial exploration, determina-tion of resectability is similar to t hat described for total gastrectomy.

Operative ProcedureEXPOSURE AND OPERATIVE TECHNIQUE The omentum is separated from thetransverse colon along the avascular plane and carefully lifted from thetransverse mesocolon to the level of the pancreas. The right gastroepiploicbranch of the gastroduodenal artery and the right gastroepiploic vein areencountered adjacent to the head of the pancreas. These are carefully iso-lated, divided, and ligated. The perigastric tissue that contains the subpy-loric nodes in the region of the pylorus is included with the specimen.Multiple small vessels encountered adjacent to the duodenum are clampedwith fine hemostats, divided, and ligated with 3-0 silk sutures. The firstpart of duodenum is carefully freed and then transected with a linear GIA-60 stapler. The gastrohepatic ligament is incised close to the liver to beincluded with the specimen. For a distal gastrectomy, at least a 5-cm prox-imal margin from the tumor is achieved. However, if the tumor extendsinto the body of the stomach or up the lesser curvature, a total gastrec-tomy is needed.


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CHAPTER 19:Gastrectomy 121

FIGURE 19-3 BillrothIIgastrojejunostorny after either a distal or subtotal gastrectorny.

After the site of transection of the stomach is determined, thedescending branch of the left gastric vessels along the lesser curvature andthe left gastroepiploic vessels along the greater curvature are carefully iso-lated, ligated in continuity with 2-0 silk, and divided. The stomach is tran-sected with either a GIA-90 linear or a TA-90 stapler. The specimen is sentt o pathology for frozen section analysis of the proximal and distal margins.Once margins have been determined to be clear of tumor, a standardBillroth I1 gastrojejunostomy is constructed as outlined for benign condi-tion (Fig. 19-31, except that it should be antecolic.CLOSURE The midline incision is closed in a standard fashion by approx-imating the linea alba with continuous 1-0 polypropylene monofilamentsutures. The skin is approximated with staples after the subcutaneoustissue has been irrigated and hemostasis achieved.

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