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Georges Karam

Publications and source records attributed to Georges Karam.

At least 19 recordsLinked to original sources

Surgical care, morbidity, mortality and follow-up after nephrectomy for renal cancer with extension of tumor thrombus into the inferior vena cava: retrospective study since 1990s.

OBJECTIVES: The aim of our survey was to evaluate surgical care, morbidity, mortality and follow-up of patients who had undergone surgical exeresis of a renal cancer with extension of tumor thrombus into the inferior vena cava. PATIENTS AND METHODS: Between June 1991 and March 2003, 40 (5.4%) patients were operated on for an enlarged nephrectomy with thrombectomy. The upper limit of the tumor thrombus was below the sus-hepatic veins in 21 (52.5%) patients and above the sus-hepatic veins in 19 (47.5%) patients with six (15%) located in the right atrium. RESULTS: Cardiopulmonary bypass (CPB) was used for 12 patients (30%). A per-operative embolism was noted for three (7.5%) patients: two cases of cruoric embolism and one case of gaseous embolism, systematically occurring in patients operated on without CPB. Early mortality was 7.5% (three patients) attributable to hemorrhagic complications. Overall survival at 2 and 5 years was 45.2% and 38.7%, respectively. Disease-free survival at 2 and 5 years was 28.3% and 8.9% respectively. Only the pN stage had a statistically significant prognosis value for overall survival but not for disease-free survival. At the end of the study, only one (2.5%) patient could be considered free of the disease with sufficient follow-up after the surgery. CONCLUSION: Patients with renal cancer and tumor extension in the inferior vena cava need multidisciplinary cooperation to adapt a good surgical strategy, particularly with the use of CPB. However, the rate of patients free of disease after such surgery was low.

Adult↗

[Morbidity and mortality of renal cancer with inferior vena cava extention according to various types of surgical management].

OBJECTIVE: The objective of this study was to evaluate the mortality and morbidity of patients operated for renal cancer with inferior vena cava extension according to the surgical management and the upper limit of the tumour thrombus. underwent radical nephrectomy with resection of neoplastic venous thrombus extending into the inferior vena cava. The upper limit of the tumour thrombus was below the hepatic veins in 21 cases (52.5%) and above the hepatic veins in 19 cases (47.50%) with invasion of the right atrium in 6 cases (150). RESULTS: Cardiopulmonary bypass (CPB) was used in 12 patients (30%). The transfusion rate was 87.5%. In the group of 19 patients with thrombus extending above the hepatic veins, the transfusion rate was lower in patients operated by CPB (p=0.008). Intraoperative embolism occurred in 3 patients (7.5%): 2 cases of thrombotic embolism and 1 case of gas embolism, always in patients operated without CPB. The early mortality was 7.5% from haemorrhagic complications. The early morbidity was 47.5%. No significant difference was observed between groups of patients operated with or without CPB in terms of morbidity (p=0.836) or mortality (p=0.896). CONCLUSION: The management of patients with renal cancer and inferior vena cava extension is complicated and requires a multidisciplinary approach. Patients operated under CPB for tumours extending above the hepatic veins have a lower transfusion rate and a lower embolic complication rate with no increase of mortality and morbidity.

Adult↗

[Oncological results of renal cancer with inferior vena cava thrombosis after nephrectomy].

OBJECTIVE: The objective of this study was to evaluate survival and risk of recurrence in patients undergoing nephrectomy with resection of inferior vena cava tumour thrombus in our department. MATERIAL AND METHODS: From June 1991 to March 2003, 40 patients underwent radical nephrectomy with resection of inferior vena cava tumour thrombus. The upper limit of the tumour thrombus was below the hepatic veins in 21 cases (52.5%) and above the hepatic veins in 19 cases (47.5%), with thrombus in the right atrium in 6 cases (15%). Cardiopulmonary bypass (CPB) was used in 12 patients (30%) RESULTS: With a mean follow-up of 28.5 +/- 36.8 months (range: 0-150), 22 patients (55%) have died. The 2- and 5-year overall survival rates were 45.2% and 38. 7%, respectively. Local and/or metastatic recurrence was observed in 28 patients (70%) after a mean interval of 18 +/- 22.9 months (range: 1-104). Patients with tumour thrombus derived from the left kidney had a higher local recurrence rate than patients with thrombus derived from the right kidney (p = 0.0194). The 2- and 5-year recurrence-free survival rates were 28.3% and 8.9%, respectively. Only stage pN had a statistically significant prognostic value on overall survival, but not on recurrence-free survival. At the end of the study, only 1 patient (2.5%) can be considered to be cured with no disease progression with a sufficient follow-up (52 months) after nephrectomy. CONCLUSION: Nephrectomy with resection of tumour thrombus from the inferior vena cava provides a gain in terms of medium-term survival, but the majority of patients are not cured by this major surgery. Only lymph node status has a prognostic value.

Adult↗

[Study of urothelial bladder tumours in renal transplant recipients].

OBJECTIVE: To study the prevalence, treatment and outcome of urothelial bladder tumours (UBT) in renal transplant recipients. PATIENTS AND METHODS: Multicentre retrospective study performed in 2004 by questionnaire sent to members of the AFU Transplantation Committee. RESULT: Seven centres returned the questionnaire with a total of 32 UBTs in 21 males and 3 females with a mean age of 63.2 +/- 10.1 years, with no history of UBT. The incidence was 255 per 100,000. The median interval between transplantation and UBT was 60 months (range: 5 to 259 months). 72% of UBTs were stage pT > or = 1 and 63% were grade 3. CIS was present in 20% of cases. 25% of patients were N+. In addition to resection of the UBT, 3 patients were also treated with mitomycin C and 1 was treated with BCG. 7 patients underwent cystectomy, with a palliative objective in 42% of cases, associated with radiotherapy-chemotherapy (2/3) or chemotherapy alone (1/3). Immunosuppressive therapy was decreased in 50% of cases. Six patients (25%) died from bladder cancer, 25% relapsed with a tumour progression rate of 50%. 46% of patients were in remission of their UBT 4% died from an intercurrent cause. 76% of survivors have a Junctional graft with no alteration of serum creatinine. CONCLUSION: Renal transplant recipients have an increased incidence of UBT, which are more aggressive and associated with a higher mortality compared to the general population. Increased surveillance and aggressive treatment therefore appear to be justified.

Female↗

Frequency and clinical implications of development of donor-specific and non-donor-specific HLA antibodies after kidney transplantation.

The involvement of immunologic and nonimmunologic events in long-term kidney allograft failure is difficult to assess. The development of HLA antibodies after transplantation is the witness of ongoing reactivity against the transplant, and several studies have suggested that the presence of HLA antibodies correlates with poor graft survival. However, they have not discriminated between donor-specific (DS) and non-specific (NDS) antibodies. A total of 1229 recipients of a kidney graft, transplanted between 1972 and 2002, who had over a 5-yr period a prospective annual screening for HLA antibodies with a combination of ELISA, complement-dependent cytotoxicity, and flow cytometry tests were investigated; in 543 of them, the screening was complete from transplantation to the fifth year postgrafting. Correlations were established between the presence and the specificity of the antibodies and clinical parameters. A total of 5.5% of the patients had DS, 11.3% had NDS, and 83% had no HLA antibodies after transplantation. NDS antibodies appeared earlier (1 to 5 yr posttransplantation) than DS antibodies (5 to 10 yr). In multivariate analysis, HLA-DR matching, pretransplantation immunization, and acute rejection were significantly associated with the development of both DS and NDS antibodies and also of DS versus NDS antibodies. The presence of either DS or NDS antibodies significantly correlated with lower graft survival, poor transplant function, and proteinuria. Screening of HLA antibodies posttransplantation could be a good tool for the follow-up of patients who receive a kidney transplant and allow immunosuppression to be tailored.

Adult↗

Switching from cyclosporine to tacrolimus in patients with chronic transplant dysfunction or cyclosporine-induced adverse events.

BACKGROUND: Progressive renal-function decline caused by chronic allograft nephropathy is the main cause of long-term failure after kidney transplantation. Moreover, chronic cyclosporine (CsA)-induced nephrotoxicity is an important nonimmunologic factor contributing to graft dysfunction and loss, and adverse events may require CsA withdrawal. METHODS: Tacrolimus (Tac) replaced CsA-based immunosuppression in 133 transplant patients (114 kidney, 15 kidney-pancreas, 4 pancreas after kidney) with progressive loss of renal function (71% of patients) or CsA intolerance (29% of patients) not responding to CsA dose-lowering. The primary end-points of this prospective study focusing on renal function were the safety and efficacy of Tac immunosuppression. RESULTS: Tac was generally well tolerated but definitively withdrawn for 23 (17%) patients (21 graft failures, 1 case of diabetes, and 1 case of clinical intolerance). Differential creatinemia (creatinemia-nadir creatinemia after transplantation) decreased significantly from 85.4+/-9.8 to 39.0+/-7.5 mumol/L (P<0.001; mean+/-SEM) after 1 year and 3.6+/-18.1 mumol/L (P<0.01) after 4 years. For patients with CsA intolerance, switch to Tac improved intolerance symptoms in all cases. Blood urea, creatinine clearance, blood total cholesterol, and triglycerides improved significantly, and the percentage of hypertensive patients remained stable with no de novo hypertension. During follow-up, one patient experienced an acute rejection episode (not histologically proven), and four died. Twenty-one (16%) transplants failed, significantly more frequently in patients with advanced renal impairment before Tac (P<0.0001). CONCLUSION: Switching from CsA to Tac can be an alternative strategy in kidney-transplant patients suffering from chronic allograft dysfunction or CsA toxicity. The persistently improved renal function over several months of evaluation suggests that in these patients, Tac might be less nephrotoxic than CsA and could prolong transplant function despite CsA failure.

Adolescent↗

A single solution for multiple organ procurement and preservation.

Two or three different solutions may be used to preserve thoracic and abdominal organs during a single procurement. The aim of this prospective, multi-center, noncomparative study was to evaluate the safety and efficacy of Celsior (study solution, solution S) as a flushing and cold storage solution for both thoracic and abdominal organs. Between August 1999 and July 2000, 72 consecutive multiple-organ procurements were performed using solution S as the sole solution for flushing out and cold-storing thoracic and abdominal grafts. Two hundred and sixty-four grafts were implanted into 245 recipients (131 kidneys, 9 kidney-pancreases, 69 livers, 34 hearts and 6 heart-lungs). The mean cold ischemia time was 21 h for kidneys (26%>24 h); 11 h 26 min for pancreases, 9 h 16 min for livers (23%>12 h), and 2 h 58 min for hearts and lungs. No cardiac failure or arrhythmia occurred on graft reperfusion. Fourteen percent of kidney recipients had delayed graft function. The mean serum creatinine level at 3 months was 123 +/- 41 micromol/l. All pancreas recipients were insulin-free at 3 months. Primary graft nonfunction occurred in one liver recipient. Complete hepatic artery thrombosis occurred in six liver recipients during the first month; four of these patients had a risk factor for thrombosis. All but three of the heart recipients were in sinus rhythm on day 1, and 65% were extubated on day 1. Inotropic drugs were necessary during the first 72 h in 25% of heart recipients. Twelve-month patient and graft survival rates were, respectively, 100% and 96% (kidney), 100% and 89% (pancreas), 88% and 83% (liver), 77.5% (heart) and 67% (heart-lung). These results suggest that Celsior, a ready-to-use solution, is safe and effective for multiple organ procurement and preservation.

Adolescent↗

The effect of a first kidney transplant on a subsequent transplant outcome: an experimental and clinical study.

BACKGROUND: Second kidney transplantations have a roughly similar clinical outcome to first transplantations. Nevertheless, the effect of the presence of the first, nonfunctional transplant at the time of the second transplantation may also influence its outcome and has not yet been specifically studied. METHODS: We analyzed the effect of the presence of a first graft on the outcome of a second graft in a rodent allograft model and in a cohort of 240 human second kidney allograft recipients. RESULTS: In rodents, 100 days subsequent to the rejection of the first graft, we observed an increase in blood but not spleen CD4(+)CD25(+) T cells, whereas no differences were observed in transcriptional patterns. Adoptive transfer of day 100 splenocytes did not prolong graft survival. Moreover, the presence of a first rejected graft does not prolong the survival of a second graft performed at a later date. In the human context, a higher incidence of patients with anti-HLA immunization and a higher % of PRA were observed in retransplant recipients with primary allograft nephrectomy. Despite a relatively low statistical power, our data do not suggest significant differences in graft outcome between recipients of second transplants with primary allograft nephrectomy and those without. CONCLUSION: Collectively, the data from both an experimental model and a large cohort of human recipients of a second graft do not suggest a beneficial effect of the presence of a first rejected graft at the time of a second transplantation.

Adolescent↗

Steroid avoidance versus steroid withdrawal after simultaneous pancreas-kidney transplantation.

Two steroid-sparing immunosuppressive regimens were prospectively compared in recipients of simultaneous pancreas-kidney transplants, one did not include steroids at all and the other included steroids for the first 3 months following transplantation. All patients received rabbit anti-thymocyte globulin, mycophenolate mofetil (MMF) and cyclosporine. Fifty patients were randomised in an open-label, single center and prospective study. The incidence of biopsy-proven acute rejection during the first 12 months after transplantation was the primary endpoint of the study. The incidence of biopsy-proven acute rejection was 4% in both groups. No statistically significant difference in patient (96 and 100%), kidney (96 and 100%) or pancreas (84 and 92%) survival was observed 1 year after transplantation in the steroid avoidance and steroid withdrawal groups, respectively. The total number of adverse events (including severe ones), length of hospitalization and infectious episodes did not differ between groups. Blood glucose and insulin levels, lipid profile and hemoglobin A1C levels did not differ statistically between the two groups. However, the 1-year serum creatinine level was significantly higher in the steroid avoidance group (132 vs. 114 micromol/L; p = 0.02). Steroid avoidance and steroid withdrawal 3 months after transplantation are safe and effective regimens for diabetic patients with pancreas-kidney transplants.

Adolescent↗

[Retrospective study of laparoscopic retroperitoneal radical nephrectomy].

OBJECTIVE: To analyse the results of laparoscopic retroperitoneal radical nephrectomy in terms of feasibility, morbidity and disease control. PATIENTS AND METHODS: Between October 1997 and May 2004, 42 laparoscopic retroperitoneal radical nephrectomies were performed in 33 men and 9 women for renal tumour. Three or four trocars were used depending on the operative findings in order to achieve oncological imperatives: primary control of the renal pedicle before mobilization of the kidney (the artery was clipped and the vein was sectioned by Endo-GIA), passage in the plane of radical nephrectomy and absence of direct contact with the tumour The operative specimen was extracted whole in an impermeable endoscopic bag by enlarging a trocar orifice to avoid any parietal contact. RESULTS: 21 right radical nephrectomies and 21 left radical nephrectomies were performed in patients with a mean age of 61.8 years (range: 36 to 83 years). The mean size of the kidney was 120 mm (range: 60 to 170 mm), for a mean weight of 430 g (range: 55 to 870 g). The mean tumour size was 46.4 mm (range: 15 to 90 mm). The mean operating time was 132 min (range: 70 to 240 mm) for an estimated mean blood loss of 120 cc (range: 0 to 1000 cc). The mean hospital stay was 8.3 days (range: 4 to 26 days). Conversion was necessary for technical difficulties in 7 cases (16.7%), venous injuries in 5 cases, arterial injury in 1 case, and difficult dissection of the perirenal fat due to a history of high-grade diffuse lymphoma in remission. The final histological stage showed 31 pT1 tumours, one pT2 tumour and 10 pT3 tumours. Four patients died in a context of metastatic diseases with a mean follow-up for our series of 15 months (range: 1 to 64 months). CONCLUSION: Laparoscopic retroperitoneal radical nephrectomy is a feasible technique, which strictly complies with the principles of cancer surgery. The main complication observed in our series was bleeding, which appears to depend on the surgeon's experience.

Adult↗

[Complications of Bricker ileal conduit urinary diversion: analysis of a series of 246 patients].

OBJECTIVE: The objective of this retrospective study was to evaluate the mortality and early and late morbidities of Bricker ileal conduit urinary diversion. PATIENTS AND METHODS: Between January 1990 and December 2002, 246 Bricker ileal conduit urinary diversion was performed in our centre in 164 males (67%) and 82 females (33%) with a mean age of 64 years (range: 9 to 90 years). Bricker diversion was performed in 73.6% of cases for underlying tumour (prostate, bladder, cervical, colon cancer), and in 26.4% of cases for benign disease (neurogenic bladder radiation bladder bladder exstrophy, incrusting cystitis). Cystectomy was associated with Bricker diversion in 62.2% of cases. The mean follow-up was 24 months (range: 1 to 151 months). The following parameters were studied: mortality and early and late medical or surgical, urological and gastrointestinal complications. RESULTS: The postoperative mortality was 6.9% (17 deaths, 16 in patients in whom Bricker diversion was performed for cancer). The early morbidity was marked by gastrointestinal complications (ileus, fistula, evisceration) in 46 cases (1.7%), 25 of which required re-operation. A medical complication was observed in 41 patients (16.7% of the series), responsible for 60% of the postoperative mortality (10 of the 17 deaths). A urinary fistula was observed in 7 patients (2.8%). The late morbidity consisted of parietal complications (incisional hernia, peristomal hernia, stricture of the stoma) in 18.3% of cases. Urological complications consisted of acute pyelonephritis (11%), ureteroileal stricture (4.9%) and urinary stones (4.9%). CONCLUSION: Bricker ileal conduit urinary diversion is associated with considerable mortality, especially in cancer patients. Early complications are essentially gastrointestinal, while late complications tend to be parietal or urological.

Adolescent↗

[Predisposing factors for ureteric strictures in renal transplantation].

OBJECTIVE: Renal transplantation is a well defined surgical procedure, but it nevertheless remains associated with a risk of medical and surgical complications. Ureteric strictures, with an incidence ranging from 2% to 7.5% according to the series, are the most frequent urological complication. The objective of this study was to determine the incidence of ureteric strictures and the existence of risk factors predisposing to the development of ureteric strictures and to evaluate their consequences on patient and graft survival, based on a single-centre retrospective series of renal transplantations. PATIENTS AND METHODS: From January 1990 to December 2002, 1787 renal transplantations were performed consecutively in our centre. Graft, donor and recipient characteristics were extracted from a computerized database and validated by an independent observer. The parameters studied included donor's age and recipient's age, donor's haemodynamic status and serum creatinine at the time of harvesting, cause of death, graft weight and number of graft arteries, cold ischaemia and reperfusion times, number of HLA incompatibilities and percentage anti-HLA immunization, time to return of graft function, acute rejection, presence or absence of a double J stent, episodes of acute pyelonephritis, CMV infection and patient and graft survival according to the Kaplan-Meier method. RESULTS: Ureteric stricture was observed in 74 patients (4.1% of cases) and a donor age greater than 65 years (p < 0.0001), the presence of more than 2 arteries on the graft (p = 0.03) and recipients with an anti-HLA immunization less than 25% (p = 0.037) were identified as independent risk factors. Furthermore, grafts complicated by ureteric stricture resumed function later (p = 0.001). The development of ureteric stricture did not have an unfavourable impact on the 10-year recipient and graft survival rates.

Adolescent↗

[Therapeutic management of ureteric strictures in renal transplantation].

OBJECTIVE: Ureteric strictures, with a reported incidence ranging from 2% to 7.5%, are the most frequent urological complication of renal transplantation. This article reports the results of open surgery and percutaneous or endoscopic techniques used to treat these strictures, based on a single-centre retrospective series of renal transplantations. PATIENTS AND METHODS: From January 1990 to December 2002, in a series of 1787 consecutive renal transplantations performed in our centre, 74 were complicated by ureteric stricture (4.1% of cases). Strictures occurred at the ureterovesical implantation in 82.4% of cases and during the first year in 88% of cases. The mean time to management of the stricture after transplantation was 9 months (range: 6 days-120 months). Criteria of success were defined by regression or even resolution of ultrasound signs of dilatation associated with stabilization of serum creatinine obtained by the external urinary diversion. Surgical or percutaneous revisions (particularly repeated changes of double J stents) were considered to be treatment failures. RESULTS: 44 strictures (59.5% of cases) were treated by open surgery and 30 (40.5%) were treated by a first-line endoscopic or percutaneous technique. In our hands, open surgical techniques (ureteropelvic anastomosis: 80% of success (n=5), ureterovesical reimplantation: 82% of success (n=11), ureteroureteric anastomosis: 100% of success (n=4)) gave better results than endourological techniques (endoscopic electrical incision: 61.5% of success (n=13), double J stent: 61.5% of success (n=13), balloon catheter dilatation: no success (n=4)). CONCLUSION: Classical open surgical revision remains the reference treatment for ureteric strictures in renal transplantation for our team.

Adolescent↗

[Unusual metastatic spread after converted laparoscopic radical nephrectomy: natural history of the tumour or role of laparoscopy?].

Retroperitoneal or transperitoneal laparoscopic radical nephrectomy is currently proposed by an increasing number of urologists as an alternative to conventional open surgery to treat renal tumours. The authors report a case of metastasis to unusual sites (sigmoid colon, small intestine, root of the nose) after converted retroperitoneal laparoscopic radical nephrectomy for a T3 renal tumour, which raises the problem of the possible role of the laparoscopic approach in this unusual metastatic progression of the disease.

Adenocarcinoma↗

Impact of graft mass on the clinical outcome of kidney transplants.

The effect of nephronic mass reduction of kidney transplants has not been analyzed specifically in a large cohort. Transplant injuries in cadaver kidney graft may have led to an underestimation of the magnitude of this factor. The aim of this study was to analyze the consequences of kidney mass reduction on transplantation outcome. The weights of 1142 kidney grafts were collected prospectively immediately before grafting. Donors and recipients <15 yr of age, simultaneous kidney/pancreas grafts, and technical failures before day 7 were excluded from the analysis. The analysis was performed on Cockroft-calculated creatinine clearance and proteinuria in 964 patients for whom all of the necessary information was available. This study reports that the smallest kidneys transplanted into the largest recipients (donor kidney weight/recipient body weight [DKW/RBW] <2 g/kg, n = 88) increased their clearance by 2.38 ml/min every month for 6 mo (P < 0.0001) and by 0.27 ml/min thereafter (P < 0.0001). Conversely, creatinine clearance did not change for the largest kidneys transplanted into the smallest recipients (DKW/RBW ratios >/=4 g/kg). Next, using a Cox model analysis, it was shown that the risk of having a proteinuria >0.5 g/kg was significantly increased for the low DKW/RBW ratios <2 g/kg with 50% of patients having a proteinuria, compared with DKW/RBW ratios >/=4 g/kg (P < 0.001). In cadaver transplant recipients, graft mass has a rapid impact on graft filtration rate and proteinuria. Avoiding major kidney/recipient inadequacy should have a significant influence on long-term transplant function.

Adolescent↗

Ureteral necrosis after kidney transplantation: risk factors and impact on graft and patient survival.

BACKGROUND: Ischemia, the main cause of ureteral necrosis in renal transplantation, cannot alone explain the late occurrence of some fistulas beyond the first postoperative month. The aim of this study, performed on a cohort of 1,629 consecutive kidney transplantations, was to analyze the risk factors implicated in the occurrence of ureteral necrosis and its impact on graft and patient survival. METHODS: Between January 1990 and December 2001, 1,629 renal transplantations were performed in the authors' center. All biologic and clinical data were computerized in a cross-audited and validated data bank (Données Informatisées et Validées en Transplantation). The parameters studied were donor age, gender, cause of death and serum creatinine before procurement; and recipient age, gender, initial disease, panel reactive antibody, retransplantation, cold ischemia time, delayed graft function, human leukocyte antigen incompatibilities, induction and maintenance immunosuppression, right or left kidney, number of arteries, site of transplantation and the presence or not of a double-J stent. The follow-up parameters were the number and timing of acute rejection episodes, cytomegalovirus (CMV) infection (viremia, polymerase chain reaction), and acute pyelonephritis. Ureteral histologic analysis was performed in 25 cases (necrosis, leukocyte infiltration, and CMV or BK virus inclusions). Uni- and multivariate statistical tests were used (alpha risk at 5%). All of the patients with ureteral necrosis had undergone neoureterocystostomy or ureteral anastomosis with the native ureter but with a systematic double-J stent. RESULTS: Ureteral necrosis occurred in 52 of the 1,629 patients (3.2%) and was significantly and independently correlated with donor age (P=0.041) and delayed graft function (P=0.016). CMV infections were also higher in the necrosis group (P=0.001), but donor CMV status was not statistically different between the two groups (36.2% vs. 36.7%). Ureteral histologic studies showed CMV and BK virus inclusions in 4 and 2 cases, respectively, and arterial and venous thrombosis in 4 and 16 cases, respectively. No pattern of ureteral rejection was observed. Ureteral necrosis did not affect the 10-year patient and graft survival, which were 87% and 66%, respectively, for the necrosis group and 86% and 58%, respectively, for the control group (P=not significant). CONCLUSIONS: The authors' data provide new information concerning a classic surgical complication after kidney transplantation. The link they have identified between the occurrence of ureteral necrosis, donor age, and delayed graft function reemphasizes the interdependence between surgical and medical complications in kidney transplantation.

Adult↗

Characterization of human CD55 and CD59 transgenic pigs and kidney xenotransplantation in the pig-to-baboon combination.

New transgenic pigs expressing combinations of regulators of complement activation and other molecules are needed to resist xenograft hyperacute rejection (HAR) and to further analyze and treat xenograft rejection. Double transgenic pigs for human CD55 (hCD55) and human CD59 (hCD59) using the promoter of the human elongation factor 1 alpha gene were generated, and their kidneys were transplanted into nonimmunosuppressed baboons. hCD55 and hCD59 were mainly expressed by the endothelial cells, and these cells showed increased resistance to complement-mediated lysis. Baboons receiving kidneys from hCD55hCD59 pigs survived for 5 and 6 days, and displayed alterations in coagulation. Thrombocytopenia and platelet microthrombi were present within the kidneys. Nontransgenic kidneys showed HAR in less than 2 days. Kidneys from pigs expressing hCD55hCD59 displayed protection against HAR in the absence of immunosuppression. Rejection was associated with coagulopathy leukocyte infiltration and a rebound of anti-alpha Gal antibodies.

Animals↗