《外科学》小肠切除术

1、小肠切除术 Resection of the Small IntestineAnatomyThe small intestine小肠 comprises: 1. Duodenum十二指肠: is an anatomically distinct structure; 2. Jejunum空肠: the proximal 2/5 of the remaining small intestine; 3. Ileum回肠: the distal 3/5 of that.No true anatomic distinction between them!Anatomy The jejunum and

2、ileum are suspended by a mesentery肠系膜, which travels obliquely from the left upper quadrant of the abdomen to right lower quadrant. The mesentery begins at the ligament韧带 of Treitz. From a base of about 15 cm ,this mesentery fans out to connect to the entire 2.5 m of the small intestine. In the mese

3、ntery resides the intestinal blood supply as well as fat and lymphatic tissue.AnatomyThe blood supply of the jejunum and ileum derives from the SMA肠系膜上动脉, which has extensive anastomotic network near the mesenteric border of the bowel called the marginal artery边缘动脉, which runs along the length of th

4、e small bowel.Venous drainage follows the course of the arteries.Anatomy Although there is no true anatomic distinction between the jejunum and ileum, some anatomic features progress in an orderly fashion over the course of the intestine and help to distinguish the two portions of the bowel: 1. marg

5、inal artery; 2. the amount of fat; 3. The thickness, color and diameter.HistologyHistologyThe intestine has four distinct functional layers: mucosa, submucosa, muscularis and serosa.IndicationsNecrosis of the wall of the small intestine with different etiologies: 各种原因引起的小肠肠管坏死：如绞窄性肠梗阻、肠扭转、绞窄性疝、急性肠系膜

6、血管栓塞等。Severe injury ：不能修补或修补困难。Complications of inflammatory bowel disease: 如穿孔、肠瘘、慢性梗阻等。 IndicationsTumorDevelopmental anomalies：e.g. Meckels diverticulum，duplications , etc.Extensive intestinal adhesions，分离困难；或虽经分离，但浆膜面损伤过大。Others: 各种胸、腹部及泌尿系手术需要用小肠移植或转流手术。Preoperative WorkupMechanical bowel prepa

7、ration,Oral antibiotics,A dose of prophylactic intravenous antibiotics (prevent wound infection, infused within 1 hour of the time of incision) : generally, a second-generation cephalosporin二代头孢 is appropriate.General Aspects of OperationAnesthesia：general or epidural硬膜外 Position：supine仰卧位Choice of

8、incisions：depends on the part of lesions, mostly right-sided exploratory incision. In Europe ,a midline incision is more preferred. Operative ProceduresThorough exploration of the entire abdomen: the liver ,pancreas, colon, stomach, and spleen should be palpated for masses, the gallbladder for stone

9、s, the omentum and peritoneal surfaces for mass lesions, the retroperitoneum for adenopathy.观查腹腔内液体的性质和量。要求：按顺序、轻柔。贯彻无菌、无瘤、微创三项基本原则。Exploration of the small intestine and its mesentery ExposureAfter exploration is complete, a retractor拉钩 should be placed in position. The small intestine may be moved

10、 to or packed to one side of abdominal cavity, and a specific section isolated for the planned procedure.Prolonged evisceration外置 of the intestine should be avoided desiccation干燥 of the serosa and tension placed on the mesenteric vessels).While entering the lumen of the small intestine, the area sho

11、uld be toweled off to prevent spillage of enteric contents and subsequent contamination of the peritoneal cavity.Operative ProceduresA, Because of the motility, many lesions can be exteriorized. The nondiseased portion of the small bowel should be placed within the intraperitoneal space and cover wi

12、th moist towels湿盐水垫 to prevent desiccation.B, The site of resection is selected, a small opening is created immediately adjacent to the bowel wall through the mesentery using a hemostat止血钳. Care is taken not to traumatize small bowel vessels entering the bowel wall.C, Small bowel vessels adjacent to

13、 the bowel wall are divided between clamps止血钳 and controlled with fine ligatures, enlarging the window.D, The area of resection is outlined by dividing the peritoneal surfaces on the mesentery. For benign lesions, the amount of mesentery that is resected may be minimal. For disease that is suspected

14、 or proved to be malignant, a wedge-shaped楔形 portion of the small intestinal mesentery, containing drainage of lymphatic vessels, should be included with the specimen.E, mesenteric vessels are individually controlled with hemostats and ligated with fine sutures.F, Completed mesenteric division.Opera

15、tive ProceduresG-1, The bowel wall is divided using a scalpel手术刀 after application of occluding bowel clamps肠钳. The clamps are applied to the bowel wall at an angle so that a spatulated anastomosis can be created,enalrging the luminal cross-section of the anostomosis.G-2, Alternatively, a GIA-type s

16、tapler can be used to divide the bowel. Spillage is prevented.H, Seromuscular sutures are placed as “corner stitches for retraction. A non-absorbable suture, 3-0 silk, may be used.I, Interrupted No. 3-0 silk seromuscular sutures are placed and tied for completion of the posterior row.J, A full-thick

17、ness inner layer of mucosal sutures is next placed. Absorbable suture is used.K, The mucosal suture is continued onto the anterior wall.Operative ProceduresL, Completion of the inner mucosal layer of interrupted sutures 间断缝合anteriorly.M, A continuous suture连续缝合 technique may also be used.N, a second

18、 layer of interrupted seromuscular No. 3-0 silk sutures is used to complete the anterior aspect of the anastomosis.O, If discrepancy in bowel size exists, a side-to-side enteroenterostomy may be preferable.P, A posterior layer of full-thickness mucosal suture is placed, using absorbable material.Q,

19、The mucosal suture is continued on the anterior aspect of the anastomosis.Operative ProceduresR, A layer of seromuscular interrupted No.3-0 silk sutures anteriorly completes the anstomosis.S, The mesenteric defect is reapproximated, through interrupted or continuous suture, to prevent internal herni

20、a formation. T, A bowel resection can be also performed laparoscopically in selected patients.U, The loop of bowel to be resected is brought through tne abdominal wall and exteriorized. The resection can be performed in the standard fashion.V, An anastomosis is performed extracorporeally and the bowel is then returned to the abdominal cavity and incision is closed.Operative ProceduresStapled side-to-sideanas