Renal Autotransplantation: 27-Year Experience at 2 Institutions.

PURPOSE: Renal autotransplantation is an infrequently performed procedure. It has been used to manage complex ureteral disease, vascular anomalies and chronic kidney pain. We reviewed our 27-year experience with this procedure. MATERIALS AND METHODS: This is a retrospective, observational study of 51 consecutive patients who underwent renal autotransplantation, including 29 at Oregon Health and Science University between 1986 and 2013, and 22 at Virginia Mason Medical Center between 2007 and 2012. Demographics, indications, operative details and followup data were collected. Early (30 days or less) and late (greater than 30 days) complications were graded according to the Clavien-Dindo system. Factors associated with complications and pain recurrence were evaluated using a logistic regression model. RESULTS: The 51 patients underwent a total of 54 renal autotransplants. Median followup was 21.5 months. The most common indications were loin pain hematuria syndrome/chronic kidney pain in 31.5% of cases, ureteral stricture in 20.4% and vascular anomalies in 18.5%. Autotransplantation of a solitary kidney was performed in 5 patients. Laparoscopic nephrectomy was performed in 23.5% of cases. Median operative time was 402 minutes and median length of stay was 6 days. No significant difference was found between preoperative and postoperative plasma creatinine (p = 0.74). Early, high grade complications (grade IIIa or greater) developed in 14.8% of patients and 12.9% experienced late complications of any grade. Two graft losses occurred. Longer cold ischemia time was associated with complications (p = 0.049). Of patients who underwent autotransplantation for chronic kidney pain 35% experienced recurrence and 2 underwent transplant nephrectomy. No predictors of pain recurrence were identified. CONCLUSIONS: The most common indications for renal autotransplantation were loin pain hematuria syndrome/chronic kidney pain, ureteral stricture and vascular anomalies in descending order. Kidney function was preserved postoperatively and 2 graft losses occurred. At a median followup of 13 months pain resolved in 65% of patients who underwent the procedure. Complication rates compared favorably with those of other major urological operations and cold ischemia time was the only predictor of postoperative complications.

Omental roll-up: a technique for islet engraftment in a large animal model.

BACKGROUND: Attrition of transplanted islets is significant after hepatic embolization. This study was designed to investigate a novel surgical technique for islet transplantation into the omentum. This site allows placement of the islets in a three-dimensional (3D) matrix, with growth factors, to temporarily culture the islets in vivo while revascularization progresses. MATERIALS AND METHODS: Five female dogs (three partial and two total pancreatectomies) received an autologous islet transplant in the omentum. Islets were suspended in 1 mL of PBS containing 10 ug of vascular endothelial growth factor (VEGF). Fresh autologous plasma (10 mL) was mixed with the islet/VEGF suspension. The coagulum containing the islets and VEGF was then placed on the greater omentum. The leading edge of omentum was rolled up to secure the islet/VEGF/coagulum in position and to present the thin islet layer with two omental surfaces for implantation. Omentum was recovered at 2, 13, 21, 42, and 180 d. RESULTS: Immunohistochemical staining for synaptophysin, glucagon, and insulin confirmed the presence of transplanted islets in all omenta. Insulin and C peptide production from the omental islets was confirmed in portal venous samples, and normalization of morning glucose levels beginning on day 7 was seen in the total pancreatectomy experiment. CONCLUSIONS: Autologous islets implant in rolled-up omentum when placed as a VEGF/autologous plasma coagulum. This technique has potential benefits, including the opportunity to accelerate revascularization and to investigate local strategies for modulating the immune response.

Reversal of diabetes in mice with a bioengineered islet implant incorporating a type I collagen hydrogel and sustained release of vascular endothelial growth factor.

We have developed a bioengineered implant (BI) to evaluate strategies to promote graft survival and function in models of islet transplantation in mice. The BI, sized for implantation within a fold of intestinal mesentery, consists of a disk-shaped, polyvinyl alcohol sponge infused with a type I collagen hydrogel that contains dispersed donor islets. To promote islet vascularization, the BI incorporates a spherical alginate hydrogel for sustained release of vascular endothelial growth factor (VEGF). BIs that contained 450-500 islets from syngeneic (C57Bl/6) donors and 20 ng of VEGF reversed streptozotocin (STZ)-induced diabetes in 100% of mice (8/8), whereas BIs that contained an equivalent number of islets, but which lacked VEGF, reversed STZ-induced diabetes in only 62.5% of mice (5/8). Between these "+VEGF" and "-VEGF" groups, the time to achieve normoglycemia (8-18 days after implantation) did not differ statistically; however, transitory, postoperative hypoglycemia was markedly reduced in the +VEGF group relative to the -VEGF group. Notably, none of the mice that achieved normoglycemia in these two groups required exogenous insulin therapy once the BIs began to fully regulate levels of blood glucose. Moreover, the transplanted mice responded to glucose challenge in a near-normal manner, as compared to the responses of healthy, nondiabetic (control) mice that had not received STZ. In future studies, the BIs described here will serve as platforms to evaluate the capability of immunomodulatory compounds, delivered locally within the BI, to prevent or reverse diabetes in the setting of autoimmune (type 1) diabetes.

Aortic extension for en bloc transplantation of horseshoe kidneys.

INTRODUCTION: We report a technique for extending the distal aorta to facilitate the transplantation of en bloc horseshoe kidneys. TECHNICAL CONSIDERATIONS: En bloc horseshoe kidneys can be transplanted by a technique that is analogous to the en bloc transplantation of small pediatric kidneys. However, the horseshoe kidney's isthmus prevents ascent of the kidney, and the fused lower poles stay below the level of the inferior mesenteric artery. Therefore, the distal aorta is behind the isthmus. Extending the distal aorta produces adequate vessel length to simplify en bloc transplantation of horseshoe kidneys. The extra aortic length is obtained by spatulating the distal common iliac arteries on their medial surfaces and bringing them together as a "pair of pants" for about 1.5 cm. This produces an arterial conduit that branches into the left and right common iliac arteries and then rejoins at the distal aorta. The aortic extension produces a useable vascular conduit that can be anastomosed to the recipient's external iliac artery. The distal inferior vena cava is anastomosed to the external iliac vein. We used this technique in 1 patient. The transplanted kidney made urine promptly and was providing normal function with a serum creatinine of 1.1 mg/dL. CONCLUSIONS: It is preferable to transplant some horseshoe kidneys en bloc using the distal aorta and inferior vena cava for vascular anastomoses. This technique extends the distal aorta and provides adequate vessel length to facilitate en bloc transplantation.

The kidney bridge procedure for bilateral ureteral loss.

Bilateral ureteral loss is an uncommon occurrence that challenges the usual reconstructive approaches. We developed a novel procedure, using autotransplantation of one kidney to bridge the ureteral deficit of the contralateral kidney. A 61-year-old woman developed long bilateral mid and distal ureteral strictures from idiopathic retroperitoneal fibrosis. The left kidney was autotransplanted to the right iliac fossa and the right ureter was anastomosed to the autotransplanted kidney's pelvis, followed by ureteroneocystostomy, all over a stent. This provided an intestine-free, physiologically normal system for draining both kidneys into the bladder. She had a stable creatinine of 1.7 mg/dL at 18 months postoperatively.