Laparoscopic surgical technique for repair of rectal and colonic tears in horses: an experimental study.

OBJECTIVE: To determine the efficacy of laparoscopic surgical techniques for repair of rectal lacerations in horses. STUDY DESIGN: Experimental study. ANIMAL OR SAMPLE POPULATION: Thirty-two segments of equine bowel placed in an equine pelvitrainer, 8 equine cadavers, and 3 normal horses. METHODS: In experiment 1, 3 laparoscopic intestinal-repair techniques were evaluated in an equine pelvitrainer: suturing with needle holders, with an automatic suture device, and stapling with a hernia stapler. In experiment 2, descending colon lacerations were sutured laparoscopically using needle holders in a pelvitrainer and in equine cadavers. In experiment 3, iatrogenic rectal lacerations were sutured laparoscopically with needle holders in horses under general anesthesia. These horses were evaluated for 7 days' postoperatively by clinical examination and blood and peritoneal fluid analysis. The horses were euthanatized 7 days' postoperatively and necropsied. The repaired colonic segments were collected for determination of bursting pressures, degree of luminal narrowing, and microscopic examination of the suture line. RESULTS: For the 3 techniques, there was no significant difference in repair time or degree of luminal narrowing, but bursting pressure was higher in segments repaired by use of needle holders or with the suture device. Colonic and rectal lacerations were sutured successfully with laparoscopic needle holders. No major complications were recorded. At necropsy, adequate healing was confirmed by a high bursting strength (>140 mm Hg) and by histologic examination. CLINICAL RELEVANCE: A novel laparoscopic method can be used to repair iatrogenic rectal lacerations in horses. Whether this method may be used for clinical cases of rectal tears must be investigated.

Vascular injuries within the hepatoduodenal ligament: recognition by laparoscopic color Doppler ultrasound.

BACKGROUND: Lesions of vascular structures are rare but serious complications of laparoscopic cholecystectomy. The purpose of this blind randomized animal study was to investigate the possibility of detecting different vascular lesions within the hepatoduodenal ligament using laparoscopic color Doppler ultrasound (LCDU). METHODS: Twenty-four lesions of the hepatic artery and portal vein were created laparoscopically in six farmer pigs using titanium clips. The following injuries were studied: (a) partial occlusion of the hepatic artery (eight cases), (b) complete occlusion of the hepatic artery (eight cases), (c) partial occlusion of the portal vein (eight cases). There were also eight cases without lesions of the vascular vessels. The order in which the injuries were created was randomly assigned. The study was performed in a blind fashion. Recognition of the injuries was attempted with LCDU. RESULTS: All injuries were recognized correctly by LCDU. There were no false positive results. The clips were reliably located. Using color Doppler imaging, partial occlusions of the hepatic artery and portal vein were visualized by changes of the blood flow from laminar to turbulent behind the clip. Complete occlusion of the hepatic artery was recognized as a complete cessation of the colored blood flow. CONCLUSION: LCDU is a very efficient tool for visualizing vascular structures and evaluating the bloodstream. Partial or complete vascular occlusion by clips that may occur as a result of difficult dissection during laparoscopic cholecystectomy can be visualized reliably using this technique.

[Biliary endo-to-end anastomosis with extramucosal titanium clips. Initial results of a new technique]. / Die biliäre End-zu-End-Anastomosierung mit extramukösen Titan-Clips. Erste Ergebnisse einer neuen Technik.

BACKGROUND: Bile duct anastomoses are still associated with a high failure rate. Although following iatrogenic bile duct transection only a positive selected group of patients get a primary end-to-end reconstruction, long-term results demonstrate an incidence of postoperative strictures up to 78%. Also in orthotopic liver transplantation biliary tract complications remain a significant cause of morbidity with an incidence of up to 49%. Since these complications can also be seen under optimal circumstances, the methodically based disadvantages of the conventional hand suturing like perforating needle injury of the choledochal wall with intraluminal suture material, the suboptimal approximation of the mucosal edges and an inhibited blood flow in the choledochal stumps caused by a suture related tissue strangulation may also responsible. Thus there is a search for alternative anastomosis techniques. METHOD: To test extramucous placed titanium clips for biliary reconstruction after complete division of the bile duct we performed an end-to-end-anastomosis in 9 pigs. Therefore we used the VCS (Vascular Closure Staples)-instruments (Auto Suture). RESULTS: The application of the VCS-clips (medium size) permitted the technical realization of a tension free, everted anastomosis with an exact approximation of the mucosal edges. One of the animals died from aero embolism intraoperatively. All the others showed a complication-free postoperative period without any signs of anastomotic leakage or stenosis (follow-up: 6 months). At histological examination there were smooth and intact mucosal surfaces in all pigs and--especially important for the development of strictures--only a very mild fibrosis and inflammation. CONCLUSIONS: The potential advantage of the VCS-clip-technique is the non-penetrating tissue approximation with optimal contact of the mucosal layers that does not compromise the blood flow in the choledochal stumps. Before clinical use can be recommended further studies are required.

Laparoscopic ultrasonography reliably visualizes bile-duct injuries - a blind randomized porcine study.

INTRODUCTION: Despite use of intraoperative cholangiography (IOC), only one-third or less of bile duct injuries that occur during laparoscopic cholecystectomy are detected at the primary operation. Therefore, there is a need to investigate other intraoperative diagnostic methods, especially laparoscopic ultrasound, for detecting bile-duct injuries. MATERIALS AND METHODS: Detection of different bile-duct injuries by laparoscopic intraoperative ultrasonography was evaluated in a blind, randomized animal study. Fifty bile-duct injuries were created using laparoscopic techniques in 23 pigs. The number of single lesions and the order in which the injuries were created was randomly assigned. The lesions created were: (1) partial occlusion by a clip, (2) complete occlusion by a clip, (3) partial laceration, (4) transection without clips, (5) transection between clips and (6) excision between clips. In addition, there were cases without lesions. Different types of clips were used. A screening of the injuries by laparoscopic ultrasound using a flexible probe was attempted. The study was performed in a blind fashion. RESULTS: Complete ultrasonographical imaging of the hepatic and common bile duct between its bifurcation and its insertion into the duodenum was accomplished in all 23 animals before surgery was performed. Eight cases without lesions were correctly recognized. In 48 of 49 cases, the injuries were detected (sensitivity 98%). In one instance, the injury was obvious without the use of ultrasound. Forty-four cases were correctly diagnosed and, in 12 cases, the injuries were equivocally differentiated (specificity of 100%, overall accuracy of 98.3%). There was only one false diagnosis. The different types of clips were also reliably differentiated. CONCLUSIONS: We conclude that laparoscopic ultrasonography can reliably visualize most relevant bile-duct injuries. A standard for doing the ultrasound examination is proposed. Direct and indirect ultrasound signs of bile-duct injuries are explained.

[Determination of fibrinogen levels in the horse with the heat-precipitation methods of Schalm and Millar]. / Messung der Fibrinogenkonzentration beim Pferd mit den Hitze-Präzipitationsmethoden nach SCHALM und MILLAR.

The purpose of this study was to investigate the usefulness of two heat-precipitation techniques (Schalm- and Millar-method) as screening tests to measure plasma fibrinogen concentration in horses. Based on the measurement of samples from 108 different horses, the coefficient of correlation (CC) for the relationship between the results with the Schalm- and with the reference-method (Jacobsson) were much lower (r = 0.78) than between the Millar- and Jacobsson-method (r = 0.94). Furthermore the Schalm-method was less precise as reflected by the greater coefficient of variation (CV, within-run precision) with a sample of low-limit fibrinogen concentration (CV = 47.4 %) and with a sample of high fibrinogen concentration (CV = 35.6 %) than the Millar-method (CV = 11.1 resp. 2.9 %). In 40 healthy horses, aged 3 to 19 years, fibrinogen values ranged from 1.82 to 4.94 g/l (2.5-97.5 %-quantil). The Millar-Method is recommended as a simple and suitable heat-precipitation assay for fibrinogen determination in the horse.