An Internist’s Illustrated Guide to Gastrointestinal Surgery - part 6 ppsx

166 Kozol It is not uncommon to encounter patients taking anticoagulant medications for a variety of conditions. The most common example would be patients taking coumadin for atrial fibrillation or for deep venous thrombosis or pulmonary embolism. In such cases, the physicians who care for the patient must determine a perioperative plan for the patient’s anticoagulation. If the indication for the anticoagulation is questionable, the anticoagulant may be stopped indefinitely. If however, anticoagulation is a necessity, as in protection of a prosthetic heart valve; the following procedure is frequently followed. The patient is instructed to stop taking coumadin 1 or 2 d prior to admission. The patient is admitted the day prior to surgery and is given intravenous-iv-heparin. The purpose of this regimen is to convert from anticoagulation, which is slow to reverse (coumadin) to anticoagulation, which is rapidly reversible (heparin). The intravenous heparin is then stopped about 2 h prior to surgery. The heparin is restarted 4–8 h postoperatively depending on the magnitude of the operation. Finally, the patient resumes his/her coumadin prior to discharge. PROCEDURE Elective colon surgery requires bowel preparation. The goal of bowel preparation is to diminish the bacterial load logarithmically. The mechanical portion of the prep is accomplished by oral laxatives, which have replaced old-fashioned enema preps. The oral prep may be performed with a high volume solution of polyethylene glycol plus electrolytes, with Fleets phospho-soda solution, or with magnesium citrate. Addi- tional antimicrobial preparation is achieved via the oral intake of poorly absorbed antibiotics such as neomycin and erythromycin base. Preoperative bowel preparation has lowered infectious complications of colon surgery from double-digit rates to single- digit rates. As with many operations, a picture or a diagram may be worth a thousand words for understanding the operation. The following description will allow better understand- ing of the diagrams. Most colon surgery is performed via a vertical midline incision. The colon receives its blood supply from arteries, which originate from the anterior surface of the aorta. The arteries are the superior mesenteric and the inferior mesen- teric arteries. The SMA branches supply 80–90% of the colon with arterial blood and the IMA 10–20%. The anastomosis between SMA and IMA branches occurs along the left side of the colon. The ascending and descending colon are fixed by peritoneal attachments. The transverse colon and sigmoid colon are mobile. The blood supply and lymphatics to the colon are contained in a sheet of fibrofatty tissue known as the mesocolon. Any colon resection involves mobilization of the colon. To mobilize the ascending or the descending colon involves dividing peritoneal attachments laterally and lifting the colon into a midline position, with the colon still attached to the aorta by the mesocolon (3). The resection margins are selected. At this point, the surgeon may choose to divide the colon at the proximal and distal resection margin or to divide the mesocolon first. The division of the mesocolon involves clamping and tying off branches of the mesen- teric arteries and veins. The colon may be divided at resection margins by use of a linear stapler or using a scalpel between bowel clamps. Once these two steps are accomplished, intestinal continuity is reestablished by using suturing or stapling tech- This is trial version www.adultpdf.com Chapter 15 / Colonic Resection 167 niques. Regardless of technique chosen, there are three technical requirements for a successful colonic anastomosis: 1. An adequate lumen. 2. An adequate blood supply. 3. Lack of tension on the anastomosis. Attention to these technical requirements during the operation may prevent postop- erative complications such as leakage and stricture formation. If the colonic resection is an emergency procedure and the colon is not “prepped” as aformentioned, or there exist extraordinary intraoperative problems, a colostomy may need to be performed. A colostomy involves bringing the colon to the anterior abdominal wall. A hole is created in the anterior abdominal wall. There are two common ways to create the colostomy. One way is to divide the colon. With this technique, the proximal end is brought through the hole in the abdominal wall as an “end colostomy” (Fig. 2A). In these cases, the distal colon is either closed and dropped back in the abdomen “the Hartman procedure” (Fig. 3A and B), or, it also is brought through the abdominal wall as a mucous fistula (Fig. 2B). The second type of colostomy is a “loop colostomy.” With a loop colostomy, the colon is not divided. Instead, a loop of colon is brought through a hole in the anterior abdominal Fig. 2. (A) Schematic diagram of an end colostomy. (B) A mucus fistula. This is trial version www.adultpdf.com 168 Kozol Fig. 3. (A) The Hartman operation. Resection of tumor containing bowel. (B) Creation of a colostomy, and oversewn blind rectal stump (Adapted from Shackelford’s Surgery of the Ali- mentary Tract, Vol IV, 5th ed. WB Saunders, Philadelphia, PA, 2002). Fig. 4. Schematic diagram of a loop colostomy. This is trial version www.adultpdf.com Chapter 15 / Colonic Resection 169 Fig. 5. Anatomy after right hemicolectomy. The terminal ileum is then anastomosed to the transverse colon. Fig. 6. Anatomy after sigmoid colectomy. The descending colon is then anastomosed to the rectum. This is trial version www.adultpdf.com 170 Kozol wall (Fig. 4). The anterior surface of the loop is opened allowing egress of stool. With either type of colostomy, an appliance is placed over the ostomy for collection of stool. As with colectomy with primary anastomosis, colectomy with colostomy may be asso- ciated with complications (4). The normal configuration of the colon is seen below in Fig. 1. The anatomy after right hemicolectomy and sigmoid colectomy are seen in Fig. 5 and 6, respectively. The anatomy after left hemicolectomy is seen in Fig. 7. COMPLICATIONS Complications of colonic surgery may be considered in two groups, generic compli- cations and complications specific to intestinal surgery. Generic complications include atelectasis, pneumonia, deep venous thrombosis, urinary retention, wound infection, fascial dehiscence, and myocardial infarction. The incidence of any of these complica- tions varies according to risk factors such as age, cigarette smoking, obesity, and pres- ence of comorbid conditions such as diabetes mellitus. Some complications are preventable with proper perioperative care. Examples include proper bowel preparation and prophylactic antibiotic use to reduce the risk of wound infection. Another example is the use of mechanical compression stockings and/or mini-dose heparin to prevent deep venous thrombosis. A detailed discussion of generic complications is beyond the scope of this chapter. Complications specific to bowel surgery include anastomotic leak and anastomotic stricture. Anastomotic leak can be caused by a variety of factors, most commonly errors in technique (5). Leaks may also be caused by an inadequate blood supply or by undue tension on the anastomosis. Anastomotic leaks are generally serious complica- tions and usually present with signs of sepsis. These signs include oliguria, tachycar- dia, fever, and leukocytosis. The patient may also develop abdominal or pelvic pain beyond expected postoperative pain. If an anastomotic leak is suspected, it may be confirmed with a gastrografin enema or with a CT scan with rectal contrast. Minor leaks that have sealed may be treated with percutaneous drainage, a nasogastric tube, and iv antibiotics. However, most commonly the patient will require diversion of the fecal stream with a proximal colostomy or ileostomy plus drainage of any abscess cavity (6). The use of an ostomy under these circumstances is usually temporary. The patient may then have restoration of the GI tract with colostomy takedown 6 wk–3 mo postoperatively. Anastomotic leaks occur in approx 5% of colonic resections. The leak rate is higher with rectal (low-pelvic) anastomoses. Anastomotic stricture is a late complication, presenting 6 mo to years postoperatively. These strictures are usually caused by low-grade ischemia at the anastomosis or a sub- clinical leak. In the latter case, the inflammatory response results in fibrosis over time strictures present with constipation, cramping discomfort, bloating, or narrow caliber stools. Strictures occur in less than 10% of colonic resections. They may be treated with endoscopic dilatation in some cases. Significant strictures often require surgical revision of the anastomosis. The complication rates for colectomy are very well established and are reflected in Table 2. All other complications such as myocardial infarction, deep venous thrombosis and pulmonary embolism occur in only 1–3% of cases. The 30-d postoperative mortality for colonic resection is 1–6% depending on the series reviewed. This is trial version www.adultpdf.com Chapter 15 / Colonic Resection 171 There are two complications specific to colostomy, parastomal hernia and colos- tomy prolapse. Parastomal hernias occur in about 10% of cases. Colostomy prolapse is slightly less common. Both of these complications may require reoperation for correction of the problem (4). Changes in Physiology and Potential Side Effects Caused by the Procedure Patients vary greatly in what they consider normal bowel function. Some patients regularly have one bowel movement per day. Others go 3–4 d without a movement. As expected then, the physiologic outcome from patient to patient after colectomy is vari- able (7). Table 3 provides a rough outline of expectations based on experience with hundreds of patients. Patients will undergo physiologic accommodation to the resection for weeks to months. Patients with long-standing diarrhea may get relief with the use of bulking agents, adjustments in diet, or antidiarrheal medications. ALTERNATIVE PROCEDURES Colonic resections have been performed laparoscopically since the early 1990s. The technical limitations of the procedure have largely been overcome. The procedure is performed with four or five trocars placed through the abdominal wall. Some resections can be preformed completely laparoscopically. Others can be performed “hand-assisted.” Table 2 Common Complications After Colon Resection Generic Complications in a Large Series of Colonic Resections Prolonged ileus 7.5% Pneumonia 6.2% Respiratory failure 5.7% Urinary tract infection 5.0% From Ref. 5. Table 3 Bowel Function After Coletomy Extent of Resection Early (1–3 mo) Bowel Changes Long-Term Bowel Changes Segmental Colectomy 2–4 BMs/d may be “loose” No discernible change (1–2 ft) Hemicolectomy 2–4 BMs/d may be liquid. 1–3 BMs/d (1/2 of colon) Subtotal Colectomy Diarrhea in form & frequency. 2–4 BMs/d (only rectum left) Total Colectomy with Diarrhea with potential incontinence. 4–8 BMs/d ileo-anal anastomosis This is trial version www.adultpdf.com 172 Kozol With the hand-assisted approach, a 5–8-cm incision is made that allows the surgeon to introduce one hand into peritoneal cavity. The procedure is still viewed entirely via the intraperitoneal camera. Surgical authorities accept laparoscopic colectomy for benign indications. There have been two major concerns voiced regarding laparoscopic colectomy for cancer. First are the many reports of trocar site recurrences of cancer in the abdominal wall. As larger volumes of data have been examined, this concern has waned. The second concern is focused on the question of lymph node dissection. Specifically, can a surgeon safely and routinely resect as much mesocolon (containing lymph nodes) using laparoscopic tech- niques compared to standard open resection. There is at least one study showing equiva- lence of lymph nodal resection between open and laparoscopic colectomy. Ongoing prospective trials will answer the most important question. That is, are survival rates ultimately different using laparoscopic compared to open techniques? Preliminary reports suggest equal survival rates. It is the author’s opinion that laparo- scopic colectomy will supplant the standard operation by 2005. COSTS The upfront costs for laparoscopic colectomy are greater than for the standard open operations. This is because of the many disposable instruments used in laparoscopic surgery. Disposable instruments may range in cost from a $50 trocar to a $500 intestinal stapler. Total disposable costs could reach $2000–$3000 for a major procedure. This increase in upfront costs may be overcome by a diminished hospital length of stay in patients undergoing laparoscopic surgery. If an 8-d stay is converted to a 4-d stay, the Fig. 7. Schematic diagram of anatomy after a sigmoid colectomy. The left or descending colon is then anastomosed to the rectum. This is trial version www.adultpdf.com Chapter 15 / Colonic Resection 173 entire disposable instrument cost could be overcome. Analysis of cost to society would have to include consideration of time out of work. In theory, minimally invasive proce- dures will allow for an earlier return to work. SUMMARY 1. The majority of colonic resections are performed for adenocarcinoma of the colon. 2. Colon resections are major operations, which require general anesthesia. Patients require bowel preparation preoperatively. The hospital stay ranges from 4–10 d based on a number of variables. 3. Because the colon is involved primarily in water absorption and waste storage, patients adapt well to resections of portions of the colon. 4. As a trend, laparoscopic colectomy will probably replace open colonic surgery during the current decade. REFERENCES 1. Zuckerman GR, Prakash C. Acute lower intestinal bleeding. Gastrointest Endosc 1999;49:228–238. 2. Allan A, Andrews H, Hilton CJ, et al. Segmental colonic resection is an appropriate operation for short skip lesions due to Crohn’s disease in the colon. World J Surg 1989;13:611–614. 3. Zollinger RM. Atlas of Surgical Operations. McGraw-Hill, New York, NY, 1993. 4. Allen-Mersh TG, Thompson JP. Surgical treatment of colostomy complications. Br J Surg 1988;75: 416–418. 5. LongoWE, Virgo KS, Johnson FE, et al. Risk factors for morbidity and mortality after colectomy for colon cancer. Dis Colon Rectum 2000;43:83–91. 6. Mileski WJ, Joehl RJ, Rege RV, et al. Treatment of anastomotic leakage following low anterior colon resection. Arch Surg 1988;123:968–971. 7. Desai TK, Kinzie JL, Silverman AL, et al. (1988) Life after colectomy. Gastro Clin North Am 1988;17: 905–915. This is trial version www.adultpdf.com 174 Kozol This is trial version www.adultpdf.com Chapter 16 / Surgery of the Rectum 175 INTRODUCTION Surgery of the rectum and anus has evolved significantly and is quite commonly performed. The following procedures are representative of the more commonly per- formed operations in this area. LOW ANTERIOR RESECTION Low anterior resection (LAR) is generally performed for carcinoma of the mid-and proximal rectum. With the training of more surgeons specializing in operations on the colon and rectum, the extent of resection has been extended to some lesions in the lower third of the rectum, less than 6 cm from the anal verge. The operation does not require a special center per se, but Rosen (1) has shown that better outcomes are obtained when it is performed by a surgeon trained in colon and rectal surgery. Indications Apart from rectal carcinoma, complicated diverticular disease or high rectovaginal fistula secondary to radiation may occasionally require LAR. 16 Surgery of the Rectum and Anus Mark Maddox, MD and David Walters, MD CONTENTS INTRODUCTION LOW ANTERIOR RESECTION ABDOMINO-PERINEAL RESECTION TOTAL PROCTOCOLECTOMY WITH END-ILEOSTOMY TOTAL PROCTOCOLECTOMY WITH ILEO-ANAL ANASTOMOSIS SURGERY FOR RECTAL PROLAPSE ANORECTAL PROCEDURES LATERAL INTERNAL SPHINCTEROTOMY HEMORRHOIDECTOMY/BANDING RUBBER BAND LIGATION OPERATIVE HEMORRHOIDECTOMY REFERENCES 175 From: Clinical Gastroenterology: An Internist's Illustrated Guide to Gastrointestinal Surgery Edited by: George Y. Wu, Khalid Aziz, and Giles F. Whalen © Humana Press Inc., Totowa, NJ This is trial version www.adultpdf.com [...]... colitis and Crohn’s disease with rectal involvement 2 The use of the intersphincteric technique for proctectomy is important and the availability of an enterostomal therapy nurse is advisable TOTAL PROCTOCOLECTOMY WITH ILEO-ANAL ANASTOMOSIS Total proctocolectomy with ileal pouch-anal anastomosis (TPC-IPAA) was initially popularized in the late 1970s as a sphincter-saving alternative to total proctocolectomy... will continue to decrease TOTAL PROCTOCOLECTOMY WITH END-ILEOSTOMY Total proctocolectomy with end-ileostomy (TPC) refers to the removal of the entire colon and rectum with permanent ileostomy Though it does not require a specialized center, it does require a surgical team skilled particularly in rectal resection The availability of an enterostomal therapy specialty nurse for both pre- and postoperative... advantage of avoiding a permanent ileostomy but generally requires at least two stages and has an increased rate of complications Cost Payments to the hospital and surgeon for this operation generally total approx $12,700 The cost of stoma appliances on a permanent basis is difficult to estimate and is not always reimbursed by insurance companies Summary 1 Total proctocolectomy with end ileostomy can... proctocolectomy with permanent ileostomy The major advantage of TPC-IPAA is its avoidance of the permanent ileostomy The disadvantages are the need for a second-stage operation (ileostomy closure) and the higher complication rate This is trial version www.adultpdf.com Chapter 16 / Surgery of the Rectum 183 Fig 2 Ileo J-pouch and anal anastomosis (A) The rectum is divided and a reservoir/pouch is then constructed... RJ, Belliveau P Proctocolectomy with ileal reservoir and anal anastomosis Br J Surg 1980 ;67 :533–538 14 DeLaurier GA and Nelson J Ileal pouch-anal anastomosis In: Hicks T, Beck D, Opelka F, Timmke A, eds Complications of Colon and Rectal Surgery Williams and Wilkins, Baltimore, MD, 19 96, p 339 15 Goldberg SM, Gordon PH, Nivatvongs S Rectal Prolapse In: Essentials of Anorectal Surgery, JB Lippincott, Philadelphia,... reported in the range of 10% (6) , though more recently rates less than 3% are seen (7) Many factors have been implicated in increased leakage rates Chief among them being anemia, diabetes, local atherosclerotic disease, and prior pelvic irradiation Anastomotic leakage leads to pelvic abscess and possibly sepsis, and requires drainage (in either an opened or closed CT-guided fashion) and usually temporary... Chapter 16 / Surgery of the Rectum 185 Fig 4 Perineal rectopexy The prolapse is reproduced, and a full-thickness circumferential incision is created through the rectal wall Once the colon has been maximally delivered, it is divided along with its mesentery, and a one-layer anastomosis is created to the distal rectal cuff Prior to anastomosis, plication of the levator ani muscles is performed and posterior... its mesentery and a one-layer anastomosis is created to the distal rectal cuff Prior to anastomosis, plication of the levator ani muscles is performed and posterior suture of the mesentery to the presacral fascia are accomplished for further fixation (Fig 4) Postoperatively, patients resume a diet immediately and are discharged within 1–2 d Complications Complications, including anastomotic stricture... after total mesorectal excision for rectal cancer Lancet 19 86; 1:1479–1482 5 Manson PN, Corman ML, Coller JA, et al Anterior resection for adenocarcinoma Lahey Clinic experience from 1 963 through 1 969 Am J Surg 19 76; 131:434–441 6 Max E, Sweeney WB, Bailey HR, et al Results of 1000 single-layer continuous polypropylene intestinal anastomoses Am J Surg 1991; 162 : 461 – 467 7 Griffen FD, Knight CD, Whitaker JM,... proctocolectomy Ann Surg 19 86; 204 :62 4 62 7 11 Corman ML, Veidenheimer MC, Coller JA, Ross VH Perineal wound healing after proctectomy for inflammatory bowel disease Dis Colon Rectum 1978;21:155–159 12 Martin LW, LeCoultre C, Schubert WK Total colectomy and mucosal proctectomy with preservation of continence in ulcerative colitis Ann Surg 1977;1 86: 477–480 13 Parks AG, Nicholls RJ, Belliveau P Proctocolectomy . and the availabil- ity of an enterostomal therapy nurse is advisable. TOTAL PROCTOCOLECTOMY WITH ILEO-ANAL ANASTOMOSIS Total proctocolectomy with ileal pouch-anal anastomosis (TPC-IPAA) was initially popularized. to TPC-IPAA for both ulcerative coli- tis and familial adenomatous polyposis is total proctocolectomy with permanent ileo- stomy. The major advantage of TPC-IPAA is its avoidance of the permanent. Rectum and Anus Mark Maddox, MD and David Walters, MD CONTENTS INTRODUCTION LOW ANTERIOR RESECTION ABDOMINO-PERINEAL RESECTION TOTAL PROCTOCOLECTOMY WITH END-ILEOSTOMY TOTAL PROCTOCOLECTOMY WITH