Retrospective Study of 28 Cases of Cholecystoduodenostomy Performed Using Endoscopic Gastrointestinal Anastomosis Stapling Equipment
Medical records were reviewed of 24 dogs and four cats that underwent cholecystoduodenostomy to relieve extrahepatic biliary obstruction. These procedures had been performed using a 30-mm endoscopic gastrointestinal anastomosis stapler. At presentation, most animals had clinical signs of vomiting and anorexia, and total bilirubin was elevated in both dogs (n=21) and cats (n=4). Pancreatitis (n=13), cholangiohepatitis (n=7), and neoplasia (n=6) were the most common underlying conditions. Sixteen dogs and two cats survived to their 2-week reevaluation. The most common cause of death was euthanasia (n=9) secondary to neoplasia (n=4), peritonitis (n=3), or respiratory arrest (n=2).
Introduction
Surgical diversion of the biliary system is indicated when patency of the bile duct cannot be reestablished after obstruction has interrupted the normal flow of bile into the proximal duodenum.1–4 Causes of extrahepatic biliary obstruction can be extraluminal (e.g., neoplasia, pancreatitis, diaphragmatic hernia), intraluminal (e.g., cholelithiasis, inspissated bile, liver flukes, blood clots), or intramural (e.g., cholangitis, biliary neoplasia, cholecystitis, stricture).1,5–8
In people, choledochoenteric anastomosis is used to relieve obstruction of the extrahepatic biliary system caused by a malignant or benign disease process.9–12 In small animals, biliary diversion is usually limited to cholecystenteric techniques because of the small size of the bile duct (2 to 3 mm in dogs and 1 to 2 mm in cats).1,5 Cholecystoduodenostomy, cholecystojejunostomy, and cholecystojejunoduodenostomy are the cholecystenteric surgical procedures used for biliary bypass in small animals. 1 The method of choice for cholecystoduodenostomy is currently the mucosal apposition technique using a simple continuous, absorbable, monofilament suture.1,2 Cystoenteric anastomosis in the proximal duodenum allows the bile to enter the duodenum and maintains normal physiology of the proximal intestines.1,2,5
The stoma created during surgery must be large enough to allow intestinal reflux to exit the gallbladder.1,2,4 Contracture of the stoma during healing, which can be up to 50%, must be considered.1 In small animals, stoma stricture and cholangiohepatitis are less likely when the stoma is at least 2.5 cm in diameter before surgery. A stoma of this original size is generally still large enough after healing to allow intestinal contents to pass, which reduces the risk of entrapment of intestinal contents and secondary cholangitis.1,2,4,5 Mucosal apposition is important for maintaining adequate stoma size, allowing early reepithelialization, and preventing excessive granulation tissue that could lead to stricture.2,4
The use of surgical staples in intestinal anastomoses minimizes the trauma and inflammation caused by multiple manipulations of the bowel, providing a rapid increase in tensile strength compared with sutured anastomoses.13–15 The use of stapling equipment also reduces surgical time.16–18 Bile-duct and colonic anastomoses using titanium vascular staples result in better perfusion and less fibrosis in the anastomotic region than sutured anastomoses. 19,20 Titanium vascular staples are also associated with improved preservation of blood supply, which allows healing by primary intention and reduces the lag phase of healing.14
Surgical objectives in animals with biliary disease include establishing a diagnosis, stopping bile leakage, and reestablishing bile flow.21 Multiple procedures have been described for relief of biliary obstruction using two simple continuous layers of absorbable monofilament suture and stapling equipment.1,2,22,23 The purpose of this paper is to review the outcomes of 28 clinical cases in which biliary obstruction was relieved by cholecystoduodenostomy performed with an endoscopic gastrointestinal anastomosis (endo-GIA) stapler.a
Materials and Methods
Criteria for Inclusion
Medical records from January 1997 through May 2005 were reviewed to identify dogs and cats that had a biliary diversion surgery at Chesapeake Veterinary Referral Surgery in Annapolis, Maryland. Animals were included in the study if the cholecystoduodenostomy was performed with a 30-mm endo-GIA stapler,a the medical record was complete, and postoperative follow-up lasted for at least 2 weeks. Data extracted from the medical records included signalment, clinical signs, duration of signs, results of pre- and postoperative laboratory tests, placement of enteral feeding tube, primary histopathological diagnosis, length of anesthesia, results of bacteriological culture, cause of death, and outcome at 2-week reevaluation.
Surgical Technique
A complete abdominal exploratory was performed in all cases. The biliary system was evaluated for obstruction, leakage, and disease. The gallbladder was compressed to evaluate patency of or leakage from the biliary outflow tract. If an obstruction or leakage was diagnosed, a cholecystotomy was performed at the fundus of the gallbladder. A bacterial culture was often taken at this time. A proximal duodenotomy was performed on the antimesenteric border at or near the level of the major duodenal papilla. The common bile duct was catheterized and flushed both normograde and retrograde with 0.9% saline. If the obstruction could not be relieved, a cholecystoduodenostomy was performed.
The gallbladder was teased away from the hepatic fossa through a combination of blunt and sharp dissection. Hemorrhage was controlled with electrocautery and/or gel foam.b To aid manipulation, a stay suture of 3-0 nylonc was placed aboral to the enterotomy and dorsal to the fundus of the gallbladder. The stapler was inserted into the duodenum, aligning the antimesenteric border of the duodenum over the center of the anvil. The other arm of the stapler was placed into the gallbladder, covering the distance from the apex to the neck. Traction was applied to the stay sutures to maintain the appropriate length and apposition of the tissues. The stapler arms were then compressed, and the stapler was fired.
After the stapler was removed, the remaining opening between the duodenum and gallbladder was closed with a simple continuous pattern of 3-0 or 4-0 absorbable, monofilament suture.d To reduce tension on the stapled portion of the anastomosis, a suture of 3-0 or 4-0 absorbable monofilament was also placed between the gallbladder and the duodenum oral to the staple line.
Outcome
Survival was defined as being alive at the 2-week evaluation, whereas nonsurvivors died or were euthanized within 2 weeks of surgery. The 2-week period was chosen, because complications resulting from failure of the cholecystoduodenostomy would likely result in clinical signs of chemical and/or septic peritonitis during this time.30
Results
Signalment
The 24 dogs included in the study consisted of various breeds of both sexes, with a mean age (± standard deviation [SD]) of 8.5 (± 2.8) years [Table 1]. Body weight at surgery ranged from 6 to 41 kg (mean 18.0±10.7 kg). The four cats that met inclusion criteria had a mean age of 9.0±5.9 years and a mean weight of 4.4±1.8 kg [Table 1].
Clinical Data
The dogs were presented with clinical signs of vomiting (n=20), anorexia (n=18), icterus (n=14), lethargy (n=11), weight loss (n=3), diarrhea (n=3), fever (n=2), and pain on abdominal palpation (n=1). Clinical signs among cats included lethargy (n=4), vomiting (n=3), anorexia (n=3), weight loss (n=2), and icterus (n=2). Duration of clinical signs ranged from 0 to 30 days (mean 9.0±6.6 days) in dogs and 14 to 120 days (mean 50.0±61.0 days) in cats.
Preoperative biochemical panels were available for 22 of 24 dogs and all four cats, but only alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, and total bilirubin were evaluated in detail [Table 2]. In dogs, mean (± SD) values were 4240.0±3002.0 U/L for alkaline phosphatase (n=22), 1088.2±864.7 U/L for alanine aminotransferase (n=21), 209.7±127.8 U/L for aspartate aminotransferase (n=10), and 9.4±6.2 mg/dL for total bilirubin (n=22). In cats, mean values for these four tests were 416.5±312.2 (n=3), 527.3±232.4 U/L (n=4), 182 U/L (n=1), and 13.7±9.6 mg/dL (n=4), respectively. All preoperative means were well above their respective reference ranges [Table 2].
Biochemical panels were repeated an average of 6.3±6.0 days (range 1 to 18 days) after surgery in 20 dogs and 10.3±12.1 days (range 1 to 24 days) after surgery in three cats. In dogs, mean postoperative values had improved, but they were still elevated for alkaline phosphatase (2225.1±2420.2 U/L, n=19), alanine aminotransferase (600.6±512.1 U/L, n=16), aspartate aminotransferase (129.9±54.0 U/L, n=6), and total bilirubin (1.9±2.4 mg/dL, n=20). Individual cases had normal postoperative values on some individual tests [Table 2]. A similar postoperative pattern was observed among cats, with mean values of 112.5±140.7 U/L (n=2), 138.0±59.4 U/L (n=3), 149 U/L (n=1), and 1.3±10.7 mg/dL (n=2), respectively.
The average anesthesia time was 138.2±36.1 minutes for the dogs (range 66 to 200 minutes) and 126.3±24.6 minutes (range 95 to 155 minutes) for the cats [Table 1]. A jejunostomy feeding tube was placed in 11 dogs and one cat, and a gastrostomy tube was placed in one cat [Table 1].
Histopathological findings revealed pancreatitis (n=13), cholangiohepatitis (n=6), neoplasia (n=4), and cholecystitis (n=1) in the dogs and neoplasia (n=3) and cholangiohepatitis (n=1) in the cats [Table 1]. Bacteriological cultures from the gallbladder in 11 dogs and three cats resulted in growth of Staphylococcus intermedius (case no. 20) and Pasteurella multocida (case no. 28). An additional bacteriological culture from a procedure to close an open abdomen on the third postoperative day (case no. 23) grew Escherichia coli, Acinetobacter baumannii, and Enterococcus faecium.
Clinical Outcome
Sixteen dogs and two cats survived to their 2-week reevaluation. Fourteen dogs were eating normally and had normal physical examinations at reevaluation. Two dogs (case nos. 7, 20) were febrile (39.8°C and 40.4°C, respectively) and had decreased appetite at reevaluation, but they responded to antibiotic therapy and were normal at subsequent recheck 4 days (case no. 20) or 10 days (case no. 7) later. One cat (case no. 28) was eating normally at 2 weeks, but the other surviving cat (case no. 26) was still being fed through a jejunostomy tube at that time.
Three animals died or were euthanized within 24 hours of surgery [Table 1]. Case no. 16 experienced respiratory arrest with bradycardia 30 minutes after extubation and was euthanized at the request of the owners. Two dogs (case nos. 1, 2) experienced postoperative hypotension and oliguric renal failure. Case no. 1 died 12 hours after surgery from cardiopulmonary arrest, and case no. 2 was euthanized 12 hours after surgery because of respiratory arrest.
Seven other cases were euthanized before their 2-week reevaluation. Details are presented below and in Table 1.
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Case no. 14 developed a fever (40.9°C), vomiting, and neutrophilia (20.7 × 103/μL, reference range 3.0 to 11.0 × 103/μL) 5 days after surgery; these signs were attributed to either dehiscence of the anastomosis or leakage from a jejunostomy tube site.
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Case no. 15 developed depression, fever (41.1°C), and tachycardia (heart rate 180 beats per minute) on day 3 after surgery. An abdominal exploratory revealed bile peritonitis from necrosis and leakage of the right lateral hepatic bile duct, which was ligated. Sump drains were placed because of the bile peritonitis. On day 6 after surgery, the abdomen was opened again because the drainage had increased and become darker in color. The cholecystoduodenostomy was intact on both reexplorations. This dog was euthanized 6 days after the original surgery for continued necrosis of the right lateral hepatic ducts, which may have resulted from disruption of the vasculature during dissection of the gallbladder in the initial surgery.
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After surgery on case no. 23, the abdomen was left open to drain bile peritonitis that had resulted from a traumatic (car accident) tear in the common bile duct 5 days before presentation. The abdomen was closed on day 3 after surgery, after it was determined that the cholecystoduodenostomy site was still intact. This dog remained in the hospital receiving intravenous (IV) fluids, IV antibiotics, and feeding through a jejunostomy tube. Ten days after surgery, the dog began vomiting and developed a fever (40.7°C) and an elevated white blood cell count (29.7 × 103/μL, reference range 5.7 to 15.0 × 103/μL) with neutrophilia and a regenerative left shift. The dog’s condition continued to deteriorate despite treatment with fresh-frozen plasma, packed red blood cells, continued IV fluids, and additional antibiotics to improve the spectrum of coverage. The owners opted for euthanasia 12 days after surgery, without a necropsy to identify the cause of the clinical signs.
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Case no. 11 was euthanized 7 days after surgery because of continued intermittent vomiting, anorexia, and the poor prognosis associated with pancreatic adenocarcinoma.
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Case no. 21 was euthanized several days after surgery by the referring veterinarian, but no further information was available.
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Two cats (case nos. 25, 27) were euthanized 3 and 5 days (respectively) after surgery, because histopathology revealed hepatic lymphosarcoma and cholangiocellular carcinoma, respectively.
Discussion
The survival rate (64%) in this study is within the range reported in the literature for small animals undergoing surgery for extrahepatic biliary obstruction (41% to 72%).5,24–27 The most common underlying cause for biliary diversion in this study was pancreatitis (n=13), which is consistent with other studies in which pancreatitis was reported in 20% to 72% of affected animals.4,5,24,26 Inflammation of the pancreas can result in extraluminal occlusion of the common bile because of its close proximity to the pancreas.27,28
The anastomotic opening created when performing a cholecystoduodenostomy should be 2.5 to 4.0 cm in diameter to reduce the likelihood of stomal stricture.1,2 The stapler used in this study created a stoma that was at least 3 cm in diameter, which should allow for adequate outflow and a reduced likelihood of postoperative stricture.2,4
Postoperative improvements in selected biochemical values were seen in 18 surviving animals, which suggests that the stoma was patent and allowed adequate bile outflow during the 2 weeks after surgery. Long-term follow-up with a complete blood count, biochemical profile, and abdominal ultrasound at 6 to 8 weeks would be necessary to explore the possibility of subclinical cholangiohepatitis or stricture of the cholecystenteric stoma. However, such long-term evaluations were not available in the current retrospective study.
Stapling is more expensive than hand-suturing of a cholecystoduodenostomy anastomosis. However, this added expense may be justified, because stapling allows shorter surgical times16 that may improve survival of animals that are debilitated by biliary obstruction. This may account for the reported 64% survival in this study, which is near the top of the range previously reported for hand-sewn procedures (41% to 72%).5,24–27 A controlled study comparing surgical time and outcome between stapling and hand-suturing is needed to further evaluate this point.
The complication rates of cholecystoduodenostomies performed with 30-mm endo-GIA stapling equipment appear to be similar to rates previously reported for hand-sewn cholecystoduodenostomies. Ten (36%) animals in the current study did not survive to the time of their 2-week reevaluation, which is comparable to mortality rates of 31% to 54% reported in the veterinary literature.5,24,26,27 Three dogs (case nos. 14, 15, 23) had postoperative clinical signs of peritonitis, but the cholecystoduodenostomy site was found to be intact in two of these animals (case nos. 15, 23) during subsequent abdominal reexploration on days 6 and 3 after surgery, respectively.
Two animals in the current study died from complications related to unresponsive postoperative hypotension. Animals with obstructive jaundice possibly have impaired myocardial contractility and decreased peripheral vascular resistance that increase their susceptibility to hypotension.29 This possibility is consistent with results of another retrospective study, in which postoperative hypotension was significantly associated with mortality.24 The absence of bile salts in the small intestine can also lead to absorption of endotoxins and subsequent endotoxemia, which can cause peripheral vasoconstriction, decreased renal blood flow, and eventual tubular necrosis from degeneration of the renal tubular epithelium.24,29 This may account for the unresponsive hypotension and anuric renal failure seen in case nos. 1 and 2 of the current study.
The types of postoperative complications in the current study were similar to complications reported in other studies. 5,24,27 Cholangiohepatitis was suspected in two dogs (case nos. 7, 20) at their 2-week reevaluations, but both improved with antibiotic therapy and were normal at subsequent rechecks.
Conclusion
A 30-mm endo-GIA stapler was used to relieve extrahepatic biliary obstructions in 28 animals. Twelve animals developed complications in the immediate postoperative period; three died or were euthanized within the first 12 hours. Nine animals were euthanized, and one died before the 2-week reevaluation. Eighteen animals survived the 2 weeks after surgery, although two of these were febrile with poor appetite at their 2-week rechecks.
Endo-GIA stapling appears to be at least as effective as traditional suturing techniques. However, prospective studies are needed to definitively compare stapling to traditional suturing for factors such as integrity of the blood supply to the anastomosis, strength of the anastomosis, and surgical duration. Long-term follow-up is also needed to investigate the occurrence rates of cholangiohepatitis in animals undergoing this type of biliary diversion surgery.
Endo GIA 30; United States Surgical, a Tyco Healthcare Group LP, Norwalk, CT 06856
Gel Foam; Pharmacia & Upjohn Company, Pharmacia Corporation, Kalamazoo, MI 49001
Ethilon; Johnson & Johnson Health Care Systems, Piscataway, NJ 08855
PDS; Johnson & Johnson Health Care Systems, Piscataway, NJ 08855
