Improved physiological properties of gravity-enforced reassembled rat and human pancreatic pseudo-islets.

Previously we demonstrated the superiority of small islets vs large islets in terms of function and survival after transplantation, and we generated reaggregated rat islets (pseudo-islets) of standardized small dimensions by the hanging-drop culture method (HDCM). The aim of this study was to generate human pseudo-islets by HDCM and to evaluate and compare the physiological properties of rat and human pseudo-islets. Isolated rat and human islets were dissociated into single cells and incubated for 6-14 days by HDCM. Newly formed pseudo-islets were analysed for dimensions, morphology, glucose-stimulated insulin secretion (GSIS) and total insulin content. The morphology of reaggregated human islets was similar to that of native islets, while rat pseudo-islets had a reduced content of α and δ cells. GSIS of small rat and human pseudo-islets (250 cells) was increased up to 4.0-fold (p < 0.01) and 2.5-fold (p < 0.001), respectively, when compared to their native counterparts. Human pseudo-islets showed a more pronounced first-phase insulin secretion as compared to intact islets. GSIS was inversely correlated to islet size, and small islets (250 cells) contained up to six-fold more insulin/cell than large islets (1500 cells). Tissue loss with this new technology could be reduced to 49.2 ± 1.5% in rat islets, as compared to the starting amount. With HDCM, pseudo-islets of standardized size with similar cellular composition and improved biological function can be generated, which compensates for tissue loss during production. Transplantation of small pseudo-islets may represent an attractive strategy to improve graft survival and function, due to better oxygen and nutrient supply during the phase of revascularization. Copyright © 2014 John Wiley & Sons, Ltd.

Liver Regeneration Induced By Extracorporeal Portal Vein Arterialization in a Swine Model of Carbon Tetrachloride Intoxication.

INTRODUCTION: This study aimed to determine whether a controlled portal blood arterialization by a liver extracorporeal device (L.E.O2 NARDO) is effective in treating acute hepatic failure (AHF) induced in swine by carbon tetrachloride (CCl4) administration. MATERIALS AND METHODS: Sixteen swine with AHF induced by intraperitoneal injection of CCl4 in oil solution were randomly divided into 2 groups: animals that received L.E.O2 NARDO treatment 48 hours after the intoxication (study group; n = 8); and animals that were sham operated 48 hours after the intoxication (control group; n = 8). Blood was withdrawn from the iliac artery and reversed in the portal venous system by an interposed extracorporeal device. Each treatment lasted 6 hours. The survival was assessed at 5 days after L.E.O2 NARDO treatment or sham operation. In both groups blood samples were collected for biochemical analysis at different study time and liver biopsies were performed 48 hours after intoxication and at humane killing. RESULTS: In the study group decreased transaminases levels and a more rapid international normalized ratio (INR) recover were detected as compared with the control group. Six animals of the study group (75%) versus 1 animal (12.5%) of the control group survived at 5 days after surgery with a statistically significant difference (P < .05). Liver biopsies performed at humane killing showed damaged areas of the livers reduced in the study group compared with biopsies of the control group. CONCLUSIONS: Arterial blood supply in the portal system through the L.E.O2 NARDO device is easily applicable, efficacious, and safe in a swine model of AHF induced by CCl4 intoxication.

Complications and graft survival in kidney transplants with vascular variants: our experience and literature review.

INTRODUCTION: In the literature several reconstructive techniques for vascular anastomoses in case of kidney graft vascular variants are reported. This article reports our experience in kidney transplants with vascular anomalies. MATERIALS AND METHODS: Between January 1996 and June 2012, 154 cadaveric kidney transplantations were performed at our center. In 35 case, vascular variants were found. Among the arterial variants we observed 27 double arteries, 2 cases with 3 arteries, and 1 case with 4 arteries. All cases of Venous variants were double veins. Based on the type of reconstructive technique used, we divided transplants into group A (n = 22) separate multiple arterial anastomoses; group B (n = 8) anastomosis on the aortic patch; group C (n = 4) single anastomosis in case of 2 arteries with a common ostium at the aortic origin. The venous variants were treated with ligation of the vein of smaller caliber. RESULTS: Kidney preparation to the back table lasted on average 50 minutes with no significant differences between the 3 groups and no significant timing increase compared to renal transplants without vascular anomalies (mean warm ischemia 40 minutes, range 30-60 minutes). The mean cold ischemia time was limited to 16 hours from the removal and the mean warm ischemia was 50 minutes (range 30-70 minutes). There were no differences in timing between group C and single anastomoses, whereas groups A and B showed mean warm ischemia time was slightly increased compared to group C (P < .05). There were no significant differences in terms of delayed upturn of graft function and graft survival between groups A, B, and C and compared to transplants without vascular anomalies. CONCLUSIONS: In our series we observed similar results performing the reimplantation on aortic patch and separate multiple arterial anastomoses. Considering our experience, we believe that vascular variants are not an indication to exclude a graft for transplantation.

Laparoscopic placement of "self-locating catheter": our experience and a review of literature.

Among the available devices for peritoneal dialysis, the Di Paolo self-locating catheter (SLC) represents a milestone using to its ability to ensure a permanent reliable means of access to the peritoneum. Our experience included 20 laparoscopic peritoneal catheter placements from 2008 to 2011. We performed the laparoscopic surgical technique using 3 trocars: 2 10 mm and 1 5 mm. The technique allows catheter introduction into the pouch of Douglas under direct vision. Among 20 treated patients, 1 died due to causes unrelated to peritoneal dialysis; 1 underwent transplantation, and 1 was switched to hemodialysis because of ultrafiltration failure. The complications included 2 catheter displacements, only 1 of them needing repositioning by open laparotomy, and 1 case of peritonitis. No infection in the subcutaneous tunnel or obstruction and malfunction occurred among our patients. The Di Paolo SLC is similar to Tenckhoff catheter but includes a small tungsten cylinder at the tip that engenders continuous gravity in the peritoneal cavity, producing a reduced risk of dislocation. In a large series of cases, Di Paolo et al. reported a 0.8% dislocation rate after SLC placement compared with 12% using Tenckhoff catheters. They also demonstrated a reduced risk of other complications, such as peritonitis, infection, obstruction, and failure. These data have been confirmed by other authors with smaller case series. Thus, introduction of the SLC and improved surgical techniques result in better efficiency of peritoneal dialysis.

Analysis of 80 dual-kidney transplantations: a multicenter experience.

INTRODUCTION: The use of kidneys from expanded criteria donors (ECD) is an attractive strategy to enlarge the pool of organs available for transplantation. Considering the fact that ECD organs have a reduced nephron mass, they are preferentially allocated for dual-kidney transplantation (DKT). Authors have reported excellent results of DKT when pretransplant ECD organs are evaluated for histological scores. The aim of this study was to evaluate DKT donor and recipient characteristics for comparison with DKT posttransplant outcomes versus those of recipients of single-kidney transplantations from expanded criteria (edSKT) and ideal donors (idSKT). We analyzed the potential prognostic factors involved in DKT among a population derived from three transplant centers. MATERIALS AND METHODS: Between 2001 and 2007, DKT (n = 80) were performed based upon the ECD kidney allocation assessed by biopsy. RESULTS: The average donor ages for the DKT, edSKT, and idSKT groups were 68.8 ± 7.8, 65.3 ± 7.2, and 40.1 ± 13.8 years, respectively (P < .001). The number of human leukocyte antigen mismatches was greater in the DKT group (3.1 ± 1.2, P < .05). Patient and graft 5-year survival rates were similar among DKT, edSKT, and idSKT recipients, namely, 97.5% versus 95.8% versus 96.9% and 93.7% versus 87.4% versus 86.9%, respectively. Mean serum creatinine values at discharge were lower in the DKT and idSKT recipients (1.5 ± 0.9 and 1.6 ± 0.7 mg/dL; P < .05) compared with the edSKT group (1.9 ± 0.7 mg/dL). Correlations between supposed prognostic factors and survival among the DKT group noted worse outcomes in reoperation cases (P < .05). CONCLUSION: We confirmed that DKT produced successful outcomes. An accurate surgical procedure is particularly important to try to avoid reoperations. In our experience, the use of a biopsy as an absolute criterion to allocate ECD kidneys may be too protective.

Urologic complications in kidney transplantation: a single-center experience.

INTRODUCTION: Urologic complications are an important cause of morbidity in kidney transplantation. To prevent this occurrence, several studies have reported the benefit of stenting. The aim of this study was to compare the efficacy of two different types of stents to protect the urinary anastomosis in kidney transplantation. METHODS: We performed a retrospective analysis of 139 kidney transplant recipients who underwent ureteralneocystostomy by the Lich-Gregoire technique between January 1995 and July 2010. On the basis of the type of stent we divided transplant patients into two groups: group A (n=90), the internal-external Bracci catheter and group B (n=49), the double-J stent. The urologic complications evaluated in both groups were: urinary tract leakage, obstruction, and infections. We also recorded the duration of the postoperative hospitalization. RESULTS: The incidences of urinary fistulae and ureteral strictures between the two groups were similar (around 3%). A higher incidence of urinary infections, however, was registered among group A compared with group B (46% vs 10%; P<.05). The postoperative hospitalization period was consequently longer in group A then group B (35 ± 3 vs 24 ± 2 days; P<.05). CONCLUSION: In our series of kidney transplantations, the occurrence of urinary fistulae and ureteral strictures was not influenced by the type of stent. The use of a double-J stent, however, appeared to be associated with a significantly decreased incidence of urinary tract infections leading to shorter postoperative hospitalizations.

Extracorporeal portal vein arterialization in man after extended hepatectomy to prevent acute liver failure: a case report.

Experimental studies have shown that increasing the oxygen supply to the liver through portal vein arterialization (PVA) enhances liver regeneration after partial hepatectomy. Moreover, our previous study demonstrated a beneficial effect of an extracorporeal device to increase the oxygenated blood to the liver and to improve the survival rate of animals subjected to subtotal hepatectomy. Herein we have reported a case of PVA through an extracorporeal device to treat a man after extended hepatectomy leading to acute liver failure (ALF). An obese 69-year-old man (body mass index > 35) affected by multiple metastases from colorectal cancer underwent 80% liver resection; at laparotomy, a steatotic liver was evident due to adjuvant chemotherapy. Moreover, the liver experienced 20 minutes of hepatic ischemia during the resection. At the end of resection he underwent extracorporeal PVA treatment. Blood was withdrawn from the femoral artery and returned into the portal venous system through the umbilical vein. An extracorporeal device was interposed between the outflow and inflow to monitor hemodynamic parameters. Starting from operating room each of six treatments lasted 6 hours per day. Serum and liver samples were collected daily. The extracorporeal device was dismounted at the seventh postoperative day. The postoperative course was assessed at 1 month. The PVA-extracorporeal treatment yielded beneficial effects for subtotal hepatectomy by decreasing serum ammonia, transaminases, and total bilirubin concentration. The international normalized ratio recovered rapidly, remaining significantly lower during the entire postoperative period. The ten-day postoperative period was uneventful. The patient was discharged in good health. He is alive and well at the moment. The arterial blood supply in the portal system through the umbilical vein using an extracorporeal device was easily applicable, efficacious, safe, and cost-effective. It may represent a novel approach to treat patients with potential ALF after subtotal liver resection.

Hand-assisted laparoscopic donor nephrectomy: analysis of the learning curve in a training model in vivo.

INTRODUCTION: Hand-assisted laparoscopic donor nephrectomy (HALDN) outcomes are impaired mainly by the risks associated with the learning curve. Considering that practice by in vivo training may reduced this risk, we recently assessed a swine model of HALDN. The aim of this study was to analyze the learning curve of HALDN using an in vivo training model. MATERIALS AND METHODS: Ten female white pigs underwent a left and then a right HALDN in the same session for a total of 20 procedures by the same first operator. The HALDN were divided into 2 groups: group A, the first 10 nephrectomies and group B, the latter 10. For each group, we assessed operative times, intraoperative complications, estimated blood loss (EBL), warm ischemia time (WIT), and graft quality. RESULTS: We observed a significant decrease in operative times among group B. Two right HALDN of group A were converted to open procedures owing to bleeding. The EBL was consequently lower in group B (P < .05); the mean WIT was not significantly different between the 2 study groups. The graft quality was good in 5/8 kidneys evaluated in group A and 9/10 in group B. DISCUSSION: Standardization of analyzed parameters after a number of procedures, which were comparable to the clinical settings, confirmed the validity of this in vivo training model and its potential utility to allow many transplantation centers to adopt this technique by reducing the risk of the learning curve.

Urological complications after kidney transplantation: experience of more than 1,000 transplantations.

OBJECTIVE: Urinary fistulas and stenoses are the most common complications that may require surgical revision after kidney transplantation. The aim of this study was to retrospectively assess the incidence of and risk factors for early (within 30 days) or late major urological complications (stenoses and fistulas) after kidney transplantation. PATIENTS AND METHODS: The study population comprised 1142 consecutive patients who underwent kidney transplantation between January 1990 and September 2007. Endpoints were early and late urological complications (stenoses and fistulas). The variables considered upon multivariate and univariate analyses were: recipient age, sex, etiology of renal failure, number (first/second) and type (single/double/combined with other organs) of kidney transplantations, cold ischemia time, type of urinary reconstruction, stent positioning, as well as donor cause of death, sex, age, and serum creatinine and clearance. We also examined the presence of graft polar arteries, acute rejection episodes, and postoperative graft function. RESULTS: Among 1142 transplantation performed at our center, 100 patients (8.7%) experienced 107 urological complications: 85 (79.4%) were early (56 fistulas, 29 stenoses) and 22 (20.5%) late (7 fistulas and 15 stenoses). Multivariate analysis for all complications revealed significant associations with male recipient sex (P = .00, HR = 2), while first kidney transplantation was protective (P = .00, HR = .4). Male gender both of the recipient and of the donor was significantly associated with early fistulas (P = .01, HR = 2.5 and P = .02, HR = 2, respectively). First (versus second) kidney transplantation had a protective effect on early stenoses (P = .01, HR = .27). Late fistulas were associated with anastomotic stenting (P = .03) in univariate but not multivariate analysis. Multivariate analysis for late stenoses did not demonstrate any significant association with the considered variables; however, the late stenosis cases showed significantly higher recipient and donor ages (P < .05) and a lower donor creatinine clearance (P < .05). The type of urinary anastomosis, stenting, cold ischemia time, presence of polar arterial branches, and type of transplantation did not influence the incidence of urinary fistulas or stenoses. CONCLUSIONS: Our data confirmed that older recipients and organs from older donors, especially of male gender, and retransplantations are to be considered risk factors for urological complications. The present analysis cannot suggest any modification of the actual surgical strategy that would prevent urological complications in kidney transplantation.

Kidney transplantation combined with other organs in Bologna: an update.

BACKGROUND: We retrospectively reviewed our experience in combined liver-kidney (L-KT) and heart-kidney (H-KT) transplantations. PATIENTS AND METHODS: Between January 1997 and April 2007, we performed 25 L-KT and 5 H-KT. Patient mean age was 51+/-8 years in L-KT and 43+/-11 years in H-KT. The main cause of liver failure was chronic viral hepatitis (14 cases). Etiology of heart failure was dilated cardiomyopathy and hypertrophic cardiomyopathy (4 and 1 patients, respectively). The main causes of renal failure in L-KT were chronic glomerulonephritis (n=8) and polycystic disease (n=7). Etiology of renal failure in H-KT was interstitial nephropathy (n=2), vascular nephropathy (n=2), and chronic glomerulonephritis (n=1). RESULTS: Mean follow-up was 32+/-26 months in L-KT and 24+/-17 months in H-KT. Immunosuppression was cyclosporine-based (n=4) or tacrolimus-based (n=21) in L-KT and cyclosporine-based in H-KT. Acute rejection rate was 8% for both liver and kidney in L-KT; 80% (mild) for heart and 40% for kidney in H-KT. In the L-KT group, there was no primary graft nonfunction (PGNF). Two patients experienced liver delayed graft function (DGF); 1 patient required postoperative dialysis. One-year graft and patient survivals were both 84% and overall graft and patient survival was 76%. In the H-KT group, 3 patients needed postoperative dialysis and 1 required a cardiac assistance device for 48 hours; overall graft and patient survival was 100% with good cardiac and renal functions. CONCLUSION: Our experience confirmed that H-KT and L-KT are safe procedures, offering good long-term results.

Multicenter study on double kidney transplantation.

BACKGROUND: Marginal organs not suitable for single kidney transplantation are considered for double kidney transplantation (DKT). Herein we have reviewed short and long-term outcomes of DKT over a 7-year experience. PATIENTS AND METHODS: Between 2001 and 2007, 80 DKT were performed in the transplant centers of Bologna, Parma, and Modena, Italy. Recipient mean age was 61+/-5 years. The main indications were glomerular nephropathy (n=33) and hypertensive nephroangiosclerosis (n=14). Mean HLA A, B, and DR mismatches were 3.1+/-1.2. Donor mean age was 69+/-8 years and mean creatinine clearance was 75+/-27 mL/min. Almost all kidneys were perfused with Celsior solution. Mean cold ischemia time was 17+/-4 hours and mean warm ischemia time was 41+/-17 minutes. Mean biopsy score was 4.4. Immunosuppression was based on tacrolimus (n=52) or cyclosporine (n=26). RESULTS: Fifty (62.5%) patients displayed good postoperative renal function. Thirty (37.5%) experienced acute tubular necrosis and required postoperative dialysis treatment; 8 acute rejections occurred. Urinary complications were 13.7% with 8/11 requiring surgical revision. There were 6 surgical reexplorations: intestinal perforation (n=2), bleeding (n=3), and lymphocele (n=1). Two patients lost both grafts due to vascular and infectious complications at 7 or 58 days after transplantation. Two patients underwent intraoperative transplantectomy due to massive vascular thrombosis. Four (5%) patients underwent transplantectomy of a single graft due to vascular complications (n=2), bleeding (n=1), or infectious complications (n=1). Graft and patient survivals were 95% and 100% versus 93% and 97% at 3 versus 36 months, respectively. CONCLUSIONS: DKT is a safe approach for organ shortage. The score used in this study is useful to determine whether a kidney should be refused or accepted.

Endolymphatic immunotherapy in inoperable hepatocellular carcinoma.

INTRODUCTION: We report the preliminary results of endolymphatic immunotherapy in patients with inoperable hepatocellular carcinoma (HCC). METHODS: From 2003 to 2005 we enrolled 31 patients with inoperable HCC. The patients underwent monthly endolymphatic injections of 15-30 x 10(6) interleukin-2 (IL-2)-activated peripheral autologous lymphocytes (LAK) and 250 IU of IL-2. Follow-up included blood biochemistry every 3 months and imaging studies every 6 months. To assess therapy efficacy we considered 12 biochemical parameters, vascular invasion or thrombosis, Child-Pugh scoring system, histological grading, lymphadenopathy, viral state, and alpha-fetoprotein. RESULTS: Sixteen patients completed at least 3 cycles, and 10 patients completed more than 6. No clinically significant adverse reactions occurred. Imaging studies showed no significant decrease in tumor mass. However, the survival of patients who completed 12 therapy cycles was significantly higher than survival of patients with fewer than 12 cycles. Both are significantly higher than that of untreated patients. All patients with 12 completed cycles showed an improvement of 9 parameters or more. DISCUSSION: Endolymphatic immunotherapy is safe, easily performed, inexpensive, and effective in terms of survival. This study should encourage future large-scale investigations so as to reach a firmer conclusion and define uniform inclusion criteria.

Extracorporeal portal vein oxygenation improves outcome of acute liver failure in swine.

BACKGROUND: Portal vein arterialization (PVA) has shown efficacy to treat acute liver failure (ALF) in preclinical studies. The next step is to perform large animal studies that propose a clinically acceptable method of PVA. In this study, we assessed the efficacy of PVA using an extracorporeal device to treat 2 ALF models in swine. MATERIALS AND METHODS: The 2 ALF swine models were carbon tetrachloride toxic ALF and subtotal hepatectomy using 8 animals per group. PVA was performed with an extracorporeal device that may be suitable for future clinical studies. Arterial blood was drawn from the iliac artery and delivered into the portal vein for a 6-hour treatment. We analyzed biochemical, blood gas, and histological parameters as well as 1-week survival rates. RESULTS: In both models, ALF was successfully achieved. Control group animals deteriorated biochemically, dropping their prothrombin times and increasing the liver enzymes. In contrast, treated animals improved with a survival rate of 75% at 7 days compared with 0% for the former group. CONCLUSIONS: PVA using an extracorporeal device was feasible and effective to treat both toxic and resective ALF in swine.

A new swine training model of hand-assisted donor nephrectomy.

INTRODUCTION: Despite the described advantages of hand-assisted laparoscopic donor nephrectomy (HALDN), the learning curve risks discourage many transplant centers to switch from the traditional technique to the laparoscopic approach. Considering that the learning curve risk may be softened with practice on a training model the aim of this study was examine a low-cost, high-fidelity model of HALDN in pigs. METHODS: Ten female white pigs underwent a left and then a right HALDN in the same session for a total of 20 procedures. For each nephrectomy, we assessed operative times and intraoperative complications. All nephrectomies were performed by a single senior transplantation surgeon. RESULTS: All animals that survived bilateral nephrectomy were sacrificed. Two right HALDNs were converted to open procedures due to bleeding. One spleen lesion and one lumbar vein injury were treated laparoscopically. Considering only the 18 HALDN completed, we registered a mean total operative time of 75.4 min (range=52 to 120). DISCUSSION: The in vivo training model described herein made it possible to reproduce the positions and operative difficulties similar to those encountered in clinical practice. Moreover, the costs can be considerably reduced by performing two procedures in each animal employing reusable instruments. Our model represented a valid high-fidelity training procedure that was useful and convenient to achieve skills for HALDN that may help transplantation centers adopt this technique to reduce the learning curve risk.

Protective effect of an inhibitor of interleukin-8 (meraxin) from ischemia and reperfusion injury in a rat model of kidney transplantation.

INTRODUCTION: Since the ischemia and reperfusion injury is one of the main causes of delayed graft function after transplantation, research efforts have focused on studying the molecules involved in this inflammatory process. The chemokine interleukin-8 (IL-8) seems to be the main one responsible through a chemoattractive action toward neutropils. Therefore, one of the strategies adopted to prevent this process is blocking the binding between IL-8 and its receptors. The aim of our study was to test the effect of meraxin, a new derivative from repertaxin, to protect the renal graft from ischemia and reperfusion injury. MATERIALS AND METHODS: Eighty male syngenic rats were divided into four groups. The control group underwent only kidney transplantation, while the other groups were treated with meraxin at various dosages 2 hours before graft reperfusion. Blood and histological samples were taken at sacrifice 24 hours after transplantation. RESULTS: Creatinine was significantly lower in the group treated with the high dosage of meraxin. Histological observation of the grafted tissue showed instead only a mild and not significant neutrophilic infiltration, equal in each group. CONCLUSIONS: Graft function was improved by the administration of meraxin at high dosage, but this effect did not seem to be connected to a reduction in inflammatory infiltration in the parechymal tissue. Maybe the cause is in the mechanisms of clotting activation, due to alteration of adhesion molecules and endothelial cells.

Bologna transplant center results in double kidney transplantation: update.

INTRODUCTION: Double-kidney transplantation is performed using organs from marginal donors with a histological score not suitable for single kidney transplantation. The aim of this study was to verify the results obtained with double-kidney transplantation in terms of graft/patient survivals and complications. PATIENTS AND METHODS: Between September 2001 and September 2006. 26 double-kidney transplantations were performed in our center. Indications for surgery were: chronic glomerulonephritis (n = 17), polycystic disease (n = 4), reflux nephropathy (n = 1), hypertensive nephroangiosclerosis (n = 4). The kidneys were all perfused with Celsior solution and mean cold ischemia time was 16.7 +/- 2.5 hours. In all cases, a pretransplant kidney biopsy was performed to evaluate the damage (mean score: 4.3). Immunosuppression was tacrolimus-based for all patients. RESULTS: Eighteen patients had good renal postoperative function, while the other eight displayed acute tubular necrosis. Two of the patients who had severe acute tubular necrosis never recovered renal function. There was only one episode of acute rejection, while the incidence of urinary complications was 31%. There were two surgical reoperations for intestinal perforation. Graft and recipient survivals were 82.7% and 100%, and 78.9% and 94% at 3 and 36 months, respectively. CONCLUSIONS: Double-kidney transplantation is a safe strategy to face the organ shortage. The score used in this study is useful to determine whether a kidney should be refused or suitable for single- or dual-kidney transplantation. The results of our experience are encouraging, but the series is too small to allow a conclusion.

Portal vein arterialization in hepatobiliary surgery and liver transplantation.

We reviewed the literature reports and our personal experience on partial portal vein arterialization (PPVA) to prevent and treat acute liver failure (ALF) following major hepatobiliary surgery or another etiology. Experimental studies in rats have assessed the efficacy of PPVA in treatment of ALF induced by extended resections in normal or fatty livers or in toxic carbon-tetrachloride damage. The treated groups showed greater survival and faster recovery of liver function. Among 11 clinical cases reported in the literature, PPVA was performed in four cases to prevent and in seven cases to treat ALF. Eight patients survived, showing rapid recovery of liver function and resolution of the clinical condition. This relatively simple procedure has shown itself able to promote liver regeneration. The PPVA procedure has shown itself to be safe and simple as well as to offer a promising approach to the failing liver.

Rat pancreatic islet size standardization by the "hanging drop" technique.

INTRODUCTION: Rejection and hypoxia are the main factors that limit islet engraftment in the recipient liver in the immediate posttransplant period. Recently authors have reported a negative relationship of graft function and islet size, concluding that small islets are superior to large islets. Islets can be dissociated into single cells and reaggregated into so called "pseudoislets," which are functionally equivalent to intact islets but exhibit reduced immunogenicity. The aim of our study was develop a technique that enabled one to obtain pseudoislets of defined, preferably small, dimensions. MATERIALS AND METHODS: Islets were harvested from Lewis rats by the collagenase digestion procedure. After purification, the isolated islets were dissociated into single cells by trypsin digestion. Fractions with different cell numbers were seeded into single drops onto cell culture dishes, which were inverted and incubated for 5 to 8 days under cell culture conditions. Newly formed pseudoislets were analyzed for dimension, morphology, and cellular composition. RESULTS: The volume of reaggregated pseudoislets strongly correlated with the cell number (r(2) = .995). The average diameter of a 250-cell aggregate was 95 +/- 8 microm (mean +/- SD) compared with 122 +/- 46 microm of freshly isolated islets. Islet cell loss may be minimized by performing reaggregation in the presence of medium glucose (11 mmol/L) and the GLP-1 analogue Exendin-4. Morphology, cellular composition, and architecture of reaggregated islets were comparable to intact islets. CONCLUSION: The "hanging drop" culture method allowed us to obtain pseudoislets of standardized size and regular shape, which did not differ from intact islets in terms of cellular composition or architecture. Further investigations are required to minimize cell loss and test in vivo function of transplanted pseudoislets.

The first case of ureteral duplication in a combined liver-kidney transplantation.

AIM: Kidney transplantation with ureteral duplication may represent a doubled risk factor in terms of ureteral stenosis or necrosis with urinary leakage usually from the site of ureteroneocystostomy. The incidence of complete duplication is very low at 0.19%. We report a kidney with ureteral duplication in the specific setting of multiorgan transplantation since it could be considered an adjunctive risk factor for urological complications. METHODS: The recipient was a 67-year old man, suffering from terminal renal insufficiency. He was also affected by HCV-related cirrhosis. The patient had been waiting for the combined transplantation for 27 months and in the last two months his hepatic function dramatically worsened. The donor was a 53-year old man who died of non-traumatic subarachnoid hemorrhage. Good HLA compatibility was observed between donor and recipient. During harvest both kidneys presented a complete ureteral duplication. So the ureters were freed together with a wide cuff of periureteral tissue and dissected distally. No vascular abnormalities were noted during the removal of either kidney. The grafts were flushed with University of Wisconsin solution and stored in the same solution. RESULTS: The liver was reperfused after 9 hours of cold ischemia. Subsequently the kidney was vascularized after 15 hours of cold ischemia. Urine production occurred immediately after revascularization. Two separated ureteroneocystostomies with a single antireflux technique were performed. Cyclosporine and steroids were given. Post-operative course was uneventful and liver and kidney function were normal. The 7-day cystography was normal. The 6, 12, 24 month ultrasonographies showed no signs of hydronephrosis or hydroureter. After 28 months renal cancer was diagnosed and the patient underwent a right nephrectomy. The liver-kidney recipient had excellent hepatic and renal function for 84.7 months. He died of malignancy from de novo tumor. CONCLUSIONS: On the basis of this experience, a kidney with an ureteral duplication, while rare, can be satisfactorily used also in combined liver-kidney transplantation.

Portal vein arterialization for the treatment of post resection acute liver failure in the rat.

INTRODUCTION: Hyperoxygenation of the liver has been suggested to improve its regenerative capacity. Thus, this study sought to determine whether an additional supply of oxygenated blood delivered by portal vein arterialization (PVA) was protective against acute liver failure induced by hepatectomy. METHODS: Sprague-Dawley rats (six per each group) were divided to either undergo PVA or be untreated after extended hepatectomy. Liver injury was evaluated by the serum alanine aminotransferase (ALT) levels. Hepatocyte regeneration was assessed by calculating the mitotic index and bromodeoxyuridine staining. The 10-day survival was assessed in separate experimental groups. RESULTS: The pO(2) in portal blood increased significantly following PVA. Serum ALT levels were significantly reduced in arterialized versus nonarterialized rats. PVA promotes liver regeneration. Finally, PVA significantly improved host survival compared to the controls: 90% versus 30%, respectively. CONCLUSION: These data suggested that an additional supply of arterial oxygenated blood through PVA promoted a rapid regeneration, leading to a faster restoration of liver mass after partial hepatectomy in rats. Thus, PVA may represent a novel tool to optimize hepatocyte regeneration.