Transplant Year

Fig. 7.9. Proportion of exocrine drained pancreas allografts according to year and transplant category.

state of the pancreas graft. To minimize graft thrombosis, prudent selection of donor pancreas grafts, short cold ischemia times, and meticulous surgical technique are necessary. Regarding the latter, it may be helpful to utilize the distal cava/proximal common iliac vein or the common iliac vein after ligation and division of the hypogastrics. Patients are often given anti-platelet agents and/or he-parin during the perioperative period to minimize the occurrence of vascular thrombosis. The quality of the pancreas graft, the age of the donor, and the cold ischemia time also influence graft thrombosis rates. Approximately 3-5% of pancreas grafts will need to be removed because of portal venous thrombosis. Arterial thrombosis is less common and is usually associated with anastomosis to atherosclerotic vessels.

2. Transplant Pancreatitis

Pancreatitis of the allograft occurs to some degree in all patients postopera-tively. It is common to see a temporary elevation in serum amylase levels for 48-96 hours posttransplant. These episodes are transient and mild without significant clinical consequence. Interestingly, it is common for patients receiving a simultaneous kidney-pancreas transplant to have a greater degree of fluid retention for several days posttransplant, compared to a kidney transplant alone recipient. Though not proven, this may be related to the graft pancreatitis that ensues during the perioperative period. The retained fluid is mobilized early post-opera-tively. It is important to minimize the risk of delayed kidney graft function by shortening cold ischemia time such that the retained third-spaced fluid may be rapidly eliminated to avoid an episode of heart failure or pulmonary edema.

3. Complications of the Bladder-Drained Pancreas Transplant

Bladder-drained pancreas transplantation is a safer procedure than enteric-drained pancreas transplantation with respect to avoiding the possibility of an intra-abdominal abscess. However, it is hampered by numerous less morbid complications. The pancreas transplant will eliminate approximately 500 cc of richly bicarbonate fluid with pancreatic enzymes into the bladder each day. Change in pH of the bladder accounts, in part, for a greater increase in urinary tract infections. In some cases, a foreign body such as an exposed suture from the duodenocystotomy acts as a nidus for urinary tract infections or stone formation.

Acute postoperative hematuria of the bladder-drained pancreas is usually due to ischemia/reperfusion injury to the duodenal mucosa or to a bleeding vessel on the suture line that is aggravated by the anti-platelet or anticoagulation protocols to minimize vascular thrombosis. These cases are self-limited but may require change in bladder irrigations and, if severe, cystoscopy to evacuate the clots. Occasionally it is necessary to perform a formal open cystotomy and suture ligation of the bleeding vessel intraoperatively. If relatively late chronic hematuria occurs, transcystoscopic or formal operative techniques may be necessary treatment.

Sterile cystitis, urethritis and balanitis may occur after bladder-drained pancreas transplantation. This is due to the effect of the pancreatic enzymes on the urinary tract mucosa. This is more commonly experienced in male recipients. Urethritis can progress to urethral perforation and perineal pain. Conservative treatment with Foley catheterization or operative enteric conversion are the extremes of the continuum of treatment. Figure 7.10 illustrates the surgical procedure of enteric conversion.

Metabolic acidosis routinely develops as a consequence of bladder excretion of large quantities of alkaline pancreatic secretions. It is necessary that patients receive oral bicarbonate supplements to minimize the degree of acidosis. Because of the relatively large volume losses, patients are also at risk of episodes of dehydration exacerbated by significant orthostatic hypotension.

Reflux pancreatitis can result in acute inflammation of the pancreas graft, mimicking acute rejection. It is associated with pain and hyperamylasemia. It is believed to be secondary to reflux of urine through the ampulla and into the pancreatic ducts. Often, the urine is found to be infected with bacteria. This frequently occurs in a patient with neurogenic bladder dysfunction. This complication is managed by Foley catheterization. Reflux pancreatitis will quickly resolve. The patient may require a complete workup of the cause of bladder dysfunction including a pressure flow study and voiding cystourethrogram. Interestingly, in older male patients, even mild hypertrophy of the prostate has been described as a cause of reflux pancreatitis. If recurrent graft pancreatitis occurs, enteric conversion may be indicated.

Urine leak from breakdown of the duodenal segment can occur and is usually encountered within the first 2-3 months posttransplant but can occur years posttransplant. This is the most serious postoperative complication of the bladder-drained pancreas. The onset of abdominal pain with elevated serum amylase, which can mimic reflux pancreatitis or acute rejection, is a typical presentation. A

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