Pancreas transplantation is established therapy for the treatment of Type 1 diabetes. As of 1998, over 11,000 transplants had been performed worldwide. Indications include the development of secondary diabetic complications such as renal insufficiency/failure, cardiovascularinsufficiency, retinopathy, neuropathy, and life-threatening glucose unawareness. Over one third of type 1 diabetics develop ESRD. Ideally, the procedure is performed before the complications reach end stage. Pancreas transplant provides tight glucose control without insulin reactions and hypoglycemic episodes. However, it does this at a cost. Immuno-suppression renders the recipient at risk for the development of certain cancers and many types of infection. For this reason, pancreas transplantation is only performed when the quality of life has become seriously impaired.
The evaluation of candidates follows a similar pattern to that of the kidney patient, with emphasis in the diabetic complications that can threaten successful transplantation. Consequently, great emphasis is placed on the cardiac and peripheral vascular workup. Cardiologic workup and clearance usually entails a peripheral vascular evaluation, chest X-rays, an EKG, a dobutamine stress echocardio-gram, and frequently a coronary angiogram. Other common tests with other transplant recipients include serologic testing (i.e., CMV, HIV, HCV, etc.), HLA, blood group testing, complete blood count (CBC), and coagulation studies, to mention a few. Ophthalmologic, neurologic, and urologic workups are performed on a case-by-case basis (Table 4.2). Absolute contraindications include active infection, recent or current history of malignancy, positive crossmatch, and HIV infection. Relative contraindications include advanced age, obesity, and cardiovascular disease. Many centers consider that, in diabetics, severe end-stage reti-nopathy or limb amputations may contraindicate pancreas allografting.
4.2.2. Simultaneous Pancreas-Kidney Transplantation (SPK)
SPK has become an accepted therapy for the treatment of patients with insulin-dependent DM and renal failure or insufficiency (creatinine clearance < 70). The predialytic patient will benefit from the reduced costs, facilitated rehabilitation, and avoidance of complications associated with dialysis and uremia. Roughly 85% of pancreata are transplanted in this manner. Patient 1-year survival is over 90%, and graft 1-year survival is over 80%. The use of dual organs from scarce cadaver sources has caused some surgeons to perform live donor nephrec-
TABLE 4.2. Workup Testing of Kidney and Pancreas Transplant Recipients
System im ls
Cardiovascular KKG. stress echocardiogram, stress thallium imaging, coronary angiogram
Pulmonary Chest X-ray, pulmonary functions tests
G astro intestinal Upper and lower endoscopies, gallbladder ultrasound
Urologie Voiding cy s to urethrogram, urodynamic studies, renal ultrasound, cystoscopy
Peripheral vascular Carotid duplex, peripheral vascular studies
Other Pap smear, mammography, abdominal X-rays, CT of head, ophtalmologie evaluation, cerebral or other angiograms, dental clearance tomy (usually laparoscopically) in conjunction with cadaver donor pancreas transplantation. The benefits include shorter wait-list time and increased long-term survival with live donor kidneys.
4.2.3. Pancreas after Kidney Transplantation (PAK)
If a Type 1 diabetic has already received a kidney from a live or cadaveric donor, a PAK transplant can be performed. A full 5% of pancreata are transplanted in this manner. The timing of the follow-up transplant does not seem to affect outcome. Assuming an acceptable organ has been procured and the recipient is healthy enough to withstand major surgery, the pancreas can be transplanted anytime after the kidney has been engrafted. Advantages of this technique include shorter wait-list times and the use of live donor kidneys, which yield greater kidney survival. Unfortunately, pancreas graft survival for PAK is significantly less than with SPK. Since results for pancreas transplantation are continually improving, this disparity is likely to decrease.
4.2.4. Pancreas Transplant Alone (PTA)
This technique has been traditionally reserved for the patient with life-threatening glucose unawareness, without secondary renal failure (i.e., with a creatinine clearance > 70). Roughly 5% of all pancreata are transplanted in this manner. Nowadays, more centers are performing pancreas transplants alone in order to correct glucose imbalance before the onset of secondary complications. Recent data state that diabetic lesions in native kidneys may regress after PTA. Unfortunately, the results have been inferior to transplants with kidneys and to transplants performed after prior kidney transplantation. Current 1-year graft survival rates for this modality stand at 52%. Most graft loss in the PTA group stems from rejection resulting from an inability to use serum creatinine as a marker for dual organ rejection. However, with newer immunosuppressants and the liberal use of pancreatic biopsy, some centers are reporting improved patient and graft survival.
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