Biliary tract reconstruction using an autologous vein graft in rats

Reconstruction of parotid duct defect with autologous vein graft and vascular coupler after buccal mucosa cancer resection

The distal end of parotid duct is often inevitably resected en-block with the buccal mucosa cancer to obtain safety margin and prevent local recurrence. Ligation of duct frequently causes complications like cheek swelling, fistula and gland function loss. The authors describe a novel procedure of combined use of autologous vein graft and vascular coupler to reconstruct the parotid duct defect for buccal mucosa cancer patients who undergo radical neck dissection and free-flap reconstruction, no lumen-stent or cannula is needed. Case examples are shown to illustrate the operative details and different outcomes for two kinds of orifice site choices. Key factors for success include the proper use of Coupler device, right choice of new orifice location and maintenance of lumen patency. For buccal mucosa cancer patients, this novel method for parotid duct reconstruction could effectively reduce postoperative complications and preserve the parotid gland function.

Feasibility of bile duct as venous graft for venous reconstruction in pancreatic surgery: An animal experimental study

OBJECTIVE

Pancreatic cancer is a kind of high malignant tumor with a poor prognosis. The aim is to determine whether the dilated bile duct can be used to reconstruct the vessels.

METHODS

An animal model of jugular vein and portal vein reconstruction was established using the bile duct. A total of 20 landrace pigs were selected to undergo jugular vein reconstruction or portal vein reconstruction using the bile duct as a patch or bridge. The patency was evaluated by color Doppler, the reconstructed segments were removed and examined macroscopically and histologically at specified intervals, and the results were compared with synthetic vessels (IMPRA straight, 10s03-19).

RESULTS

The lumen was patent, although a low level thrombosis was observed when jugular or portal vein patching was used. For bridging, stenosis of the lumen was observed, and necrosis appeared when the bile duct was used for bridging, indicating that it is feasible to reconstruct the jugular vein and portal vein with a bile duct patch. However, the bridge was not feasible possibly due to loss of blood supply, and consequent necrosis and fibrosis.

CONCLUSION

The bile duct is technically feasible, but the outcomes are unsatisfactory.

Morphological changes during creation of a neo-bile duct using a vein and a biodegradable endoluminal stent

Major bile duct lesions are usually treated by a hepaticojejunostomy which is often complicated by cholangitis and liver fibrosis. The aim of this study was to investigate the morphologic features of a neo-bile duct created from a vein and a biodegradable endoluminal stent. The neo-bile duct was created using a segment of the external jugular vein which was endoluminally stented by a biodegradable poly-lactate-acid stent. In 18 pigs, the common bile duct was resected and replaced by the vein with (n = 12) or without endoluminal stent (n = 6). Six animals served as controls. Survival, liver function and morphological changes of the neo-bile duct and the liver were observed for six months. After six months, the neo-bile duct morphologically resembled the native bile duct showing Ck7-positive columnar epithelium and newly formed capillaries in the bile duct wall. The biodegradable stent disappeared after four months. All animals survived and showed normal liver function and no cholestasis. In contrast, after sole vein reconstruction of the bile duct, four animals died due to biliary peritonitis and cholangitis. Creation of a neo-bile duct which morphologically resembles the native bile duct is feasible by using a body's own vein and a biodegradable endoluminal stent.

Bile duct replacement using an autologous femoral vein graft: an experimental study. Preliminary results

The repair of common bile duct injuries is a complex procedure with a significant rate of postoperative morbidity and mortality. The aim of this study was to demonstrate the usefulness of the autologous vein graft in replacement of the bile duct. Twelve male Sprague-Dawley rats weighing 350+/-550 g were used in the study and were divided at random into two groups: the control group (60) and the experimental group in which a 3-mm segment of the bile duct was resected and the biliary tract was replaced by a segment of vein aided by stent (G1). Both groups were subdivided into pairs of rats to study at 30, 60, and 120 days. All of the animals underwent radioisotope cholangiography, a repeat laparotomy, and blood tests for further pathologic study. The clinical evaluation and biochemical nuclear medicine and pathologic studies showed no evidence of cholestasis. The histologic study of the graft showed replacement of the endothelium by biliary-appearing epithelium. The use of an autologous vein graft with a supporting stent proves to be a feasible and alternative procedure for bile duct reconstruction. Further experimental studies should be carried out to validate these findings so they can be implemented in clinical cases.

Reconstruction of Traumatic Stensen Duct Defect Using a Vein Graft as a Conduit: Two Case Reports

Treatment of Stensen duct defect is still controversial. The authors describe the successful use of a retrograde vein graft as a conduit for traumatic segmental Stensen duct defect reconstruction. One patient sustained facial trauma with severe duct crushing and severance, the other had multiple cutting injuries with segmental duct defect. However, primary repair was impossible. A retrograde vein graft harvested from forearm for Stensen duct defect reconstruction was performed using microsurgical technique. A silicon stent was retained for 8 weeks. The sialographic examination showed good functional results without stricture postoperatively. This could be an option for treating such a complicated defect.