Anastomotic stenosis

Recently, Bharat et al. [23] showed that their so-called piggyback straight-line onlay technique led to a significant reduction in juxta-anastomotic stenosis, which is the leading cause for fistula failure. In this technique, an anastomosis between the posterior (underside) aspect of the vein and the anterior (upper) aspect of the artery is created and the arterial blood is supposed to flow into a straight cylindrical lumen. 

Bharat A, Jaenicke M, Shenoy S A novel technique of vascular anastomosis to prevent jux-ta-anastomotic stenosis following arteriovenous fistula creation. J Vase Surg 2012 55 274-280. 

In Japanese, moyamoya means puff of smoke and describes the characteristic radiological appearance of the fine anastomotic collaterals that develop from the perforating and pial arteries at the base of the brain, the orbital and ethmoidal branches of the external carotid artery and the leptomeningeal and transdural vessels in response to severe stenosis or occlusion of one, or both, distal internal carotid arteries (Yonekawa and Khan 2003). The circle of Willis and the proximal cerebral and basilar arteries may also be involved. 

Fig. 22.8a,b. Stenosis of hepaticojejunostomy. Coronal oblique MIP 3D heavily T2-weighted MR cholangiogram (a) and MR VR enlargement (b) accurately depict an anastomotic stricture (arrow) with marked dilation of the pre-anastomotic extra and intrahepatic biliary systems... 

A well-functioning VA provides the prescribed blood flow (without recirculation) that ranges from 200 to 500 ml/min during dialysis treatment. Over 90% of VA dysfunction is a result of stenotic problems developing in the access circuit. Manifestation of dysfunction depends on the location of stenosis in the circuit, its diameter relative to volume of blood flow and the outflow pattern [11]. A stenosis located in the juxta-anastomotic artery or vein tends to reduce inflow. A stenosis located in the outflow vein beyond the needling segment tends to in-... 

Stenosis is a common problem for AVFs and AVGs and represents the main cause of dysfunction and thrombosis, and the choice of the best method for repair depends on the location of the lesion. Access stenosis has been classified based on its location as juxta-anastomotic (type I), in the cannulable segment (type II) and at the outflow into the deep venous system (type III) [4] (fig. 1). There are two additional categories of stenoses not involving the access itself, those of the central veins caused by longstanding catheters and those of the arterial inflow [5]. 

Breakdown of suture lines and leakage are a common complication of the early postoperative phase. Afferent loop syndrome is a specific problem of Billroth II procedures and is caused by mechanical obstruction usually from adhesions. Internal hernias, extrinsic compression, bowel stenosis may also occur. Bezoar formation in the gastric remnant, anastomotic ulcers, incisional hernia of the abdominal wall and hiatal hernia are all also potential complications. Stenosis of the gastrojejunostomy after Billroth II procedures leads to obstruction (Fig. 13.14). Fistula after Billroth II is rare (Fig. 13.15). Tumour of the gastric renmant can be due to recurrence or present as a primary carcinoma of the stump (Fig. 13.16). 

These observations led to the development of the bicaval anastomotic technique. Left atrial anastomosis is carried out as prescribed above (see Sect. 2.1.3.3.3). Then separately the SVC and IVC are anastomosed with the intact right donor atrium in an end-to-end fashion with continuous whip stitch using a 4-0 and 5-0 polypropylene suture respectively (Fig. 2.1.4). Care has to be taken to avoid an angulation or stenosis (Morgan and Edwards 2005) of the SVC, which can create a pressure gradient or increase the difficulty of passing a bioptome... 

Non-anastomotic biliary strictures occur secondary to hepatic artery thrombosis or stenosis, preservation injury, ABO blood group incompatibility, and chronic ductopenic rejection. They are frequently multiple. Isolated non-anastomotic strictures of the donor extra-hepatic or intra-hepatic biliary tree may... 

Fig. 4.2. 25. Bile duct anastomotic stricture. A 37-year-old female status post fulminant acute hepatitis A, followed by orthotopic cadaveric liver transplant presenting now with abnormal liver function tests. Coronal thick-slab T2-weighted single-shot fast spin echo (SSFSE) MRCP image shows a short-segment stenosis (arrow) at the biliary anastomosis with upstream dilatation of the common bile duct. The remnant of the cystic duct (arrowhead) and a small amount of hyperintense fluid in the duodenal lumen (asterisk) are also seen...

MRCP is helpful in the detection of biliary strictures, bile leaks, and biloma formation. Thick-slab MRCP images are particularly useful in the presence of biliary dilatation (Fig. 4.2.25). However, proximal biliary dilatation may be absent in the transplanted patient with stenosis at the anastomotic site (Laghi et al. 1999 Pandharipande et al. 2001). Careful analysis of thin-slice MR images can help to identify the stricture and/or leak (Fig. 4.2.26). False MR positive and negative results may occur in the presence of surgical clips due to susceptibility artifact obscuring the biliary ducts. 

The most common airway problems are anastomotic dehiscence and bronchial stenosis due to strictures. The reason is mostly a lack of perfusion of the bronchial tree, as the donor airways depend on a retrograde pulmonary-to-bronchial arterial circulation until revascularization of the bronchus wall occurs. Ischaemia is greater on the right main bronchus than on the left, therefore anastomotic healing is better on the left and early stenotic problems or dehiscence occur on the right anastomosis more frequently than on the left side. In the early years of transplantation the en bloc technique was mainly performed with a high incidence of tracheal dehiscence, which prompted the development of bilateral lung transplantation. 

Scheduled bronchoscopies are performed routinely during the first year after transplantation at most transplant centres. Inspection of the anastomotic sutures, control of anastomotic wound healing, BAL with microbiologic cultures and transbronchial biopsies are taken to document lung tissue quality and to diagnose acute or chronic lung rejection, invasive infections and eventually to perform interventional procedures such as dilatation or stenting of bronchial stenosis. 

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