Kidney transplantation: the evolving challenges.

Kidney transplantation is the treatment of choice for patients with end stage renal disease. Kidney transplantation not only improves the quality of life but also prolongs life. Over the last decade, the short-term allograft survival rate has been improved dramatically. Chronic allograft nephropathy and death from cardiovascular diseases become predominant causes of later graft loss. Prevention and treatment of these disease processes require a comprehensive approach. The ever-increasing shortage of organ supply becomes the greatest challenge for the transplant community and modern medicine. More and more patients are waiting for organs; many of them are dying while waiting. Xenotransplantation and organ engineering and cloning are promising techniques and can potentially provide organs for transplantation in the future.

Duct-to-duct biliary anastomosis for patients with sclerosing cholangitis undergoing liver transplantation.

BACKGROUND: Due to the association of strictures within the biliary ductal system, Roux-en-Y choledochojejunostomy has been the preferred method of anastomosis for liver transplant recipients with primary sclerosing cholangitis (PSC). The aim of this study was to evaluate duct-to-duct anastomosis in patients with PSC who undergo liver transplantation. METHODS: Data were collected and evaluated based on demographics, type of anastomosis preformed, malignancies, outcomes comparisons, and survival. RESULTS: Of the 60 patients transplanted for PSC, 58 were diagnosed PSC prior to transplantation and 2 were diagnosed on explant. The Roux-en-Y group (n = 38) were similar in age, gender, and race when compared to the duct-to-duct (d-d) group (n = 22). There were similar rates of anastomotic revisions when comparing d-d anastomosis with Roux-en-Y (2 [9.1%] versus 2 [5.3%], P = NS) owing to bile leaks. Based on radiologic interventions of the bile ducts, seven (18.4%) in the Roux-en-Y group had interventions compared to two (9.1%) in the duct-to-duct group (P = NS). There was also no difference in recurrence of PSC: three (7.9%) in the Roux-en-Y group compared to two (5.3%) in the duct-to-duct group (P = NS). Survival at 4 years were similar between each group (76.5% [+/- 0.07] Roux-en-Y versus 84.9% [+/- 0.08] duct-to-duct, P = NS). CONCLUSION: Duct-to-duct anastomosis at the time of liver transplantation is both safe and efficacious when used in patients with PSC. Outcomes as described by surgical interventions, radiologic interventions, retransplantation, and survival were similar between groups.

Risk factors for slow graft function after kidney transplants: a multivariate analysis.

BACKGROUND: We previously defined an intermediate group of cadaver kidney transplant recipients who do not have immediate graft function (IGF), but do not have sufficient graft dysfunction to be classified as having delayed graft function (DGF). We showed that this group with slow graft function (SGF) had an increased risk of rejection and inferior long-term results vs. recipients with IGF. The aim of our current study was to determine risk factors for SGF, which have not been well defined (in contrast to risk factors for DGF). METHODS: Between January 1, 1984 and September 30, 1999, we performed 896 adult cadaver kidney transplants at the University of Minnesota. Recipients were analysed in three groups based on initial graft function: IGF [creatinine (Cr) < 3 mg/dL by post-operative day (POD) no. 5], SGF (Cr > 3 mg/dL on POD no. 5, but no need for dialysis), and DGF (need for dialysis in the first week post-transplant). A multivariate analysis looked specifically at risk factors for SGF, as compared with risk factors for DGF. Outcomes with regard to graft survival and acute rejection (AR) rates were determined for the three groups. RESULTS: Of the 896 recipients, 425 had IGF, 238 had SGF, and 233 had DGF. A multivariate analysis of risk factors for SGF showed donor age >50 yr (RR=3.3, p=0.0001) and kidney preservation time >24 h (RR=1.6, p=0.01) to be the most significant risk factors. A multivariate analysis of risk factors for DGF showed similar findings, although high panel-reactive antibodies (PRA) and donor Cr >1.7 mg/dL were also significant risk factors for DGF. Initial function of the graft significantly influenced the subsequent risk of AR: at 12 months post-transplant, the incidence of AR was 28% for those with IGF, 38% for those with SGF, and 44% for those with DGF (p=0.04 for SGF vs. DGF). Initial graft function also significantly influenced graft survival: the 5-yr death-censored graft survival rate was 89% for recipients with IGF, 72% for those with SGF, and 67% for those with DGF (p=0.01 for IGF vs. SGF; p=0.03 for SGF vs. DGF). CONCLUSIONS: SGF represents part of the spectrum of graft injury and post-transplant graft dysfunction. Risk factors for SGF are similar to those seen for DGF. Even mild to moderate graft dysfunction post-transplant can have a negative impact on long-term graft survival.

Outcome of other organs recovered during in situ split-liver procurements.

Split-liver transplantation is becoming a useful technique to expand the donor pool. Whether the split should be performed in situ or ex situ is not clear. One potential disadvantage of in situ splits is that prolonged surgical time and increased blood loss may negatively affect the function of other solid organs (kidneys, pancreas, and heart) procured from the same donor. Therefore, we studied the function of other organs posttransplantation. Between September 1, 1999, and March 31, 2000, we performed six in situ splits at the University of Minnesota (Minneapolis, MN). These six splits yielded six right-lobe liver grafts and six left-lobe liver grafts, which were transplanted into 12 adult-size recipients. Other grafts obtained from these six donors were as follows: kidney (n = 11), heart (n = 4), lungs (n = 1), pancreas (n = 2), and kidney-pancreas (n = 1). We then analyzed posttransplantation function of these grafts and the postoperative course of transplant recipients. All six donors were hemodynamically stable at the time of procurement. Mean donor age was 19.7 years. Mean surgical time for the procurement was 7.4 hours, with an average blood loss of 490 mL during in situ splitting of the liver. The 12 liver grafts showed good initial function with no primary nonfunction. The other organs also showed good function. Of 11 kidney recipients, only 1 patient developed delayed graft function, which resolved within 4 days. In addition, 1 kidney was lost early because of severe acute rejection. For the 10 recipients with functioning kidneys, mean creatinine level at hospital discharge was 2.0 mg/dL, and mean creatinine level after an average 9-month follow-up was 1.3 mg/dL. Of the 4 heart transplant recipients, 3 patients had good graft function immediately posttransplantation, with an ejection fraction greater than 60%, minimal inotropic requirements, and no surgical complications. The fourth heart transplant recipient, a critically ill status 1 patient, had poor initial function and a prolonged intensive care unit stay. At hospital discharge, pancreas and pancreas-kidney transplant recipients were all insulin free, with good urine amylase levels, no surgical or infectious complications, and no evidence of significant pancreatitis posttransplantation. The kidney of the pancreas-kidney transplant recipient functioned immediately; creatinine level after 7 months of follow-up was 1.2 mg/dL. Despite increased surgical time and blood loss, in situ splitting of liver grafts can be accomplished in stable donors without significant negative effects on other organs.

Pancreas after kidney transplants.

BACKGROUND: For certain uremic diabetic patients, a sequential transplant of a kidney (usually from a living donor) followed by a cadaver pancreas has become an attractive alternative to a simultaneous transplant of both organs. The purpose of this study was to compare outcomes with simultaneous pancreas-kidney (SPK) versus pancreas after kidney (PAK) transplants to determine advantages and disadvantages of the two procedures. METHODS: Between January 1, 1994, and June 30, 2000, we performed 398 cadaver pancreas transplants at our center. Of these, 193 were SPK transplants and 205 were PAK transplants. We compared these two groups with regard to several endpoints, including patient and graft survival rates, surgical complications, acute rejection rates, waiting times, length of hospital stay, and quality of life. RESULTS: Overall, surgical complications were more common for SPK recipients. The total relaparotomy rate was 25.9% for SPK recipients versus 15.1% for PAK recipients (P = 0.006). Leaks, intraabdominal infections, and wound infections were all significantly more common in SPK recipients (P = 0.009, P = 0.05, and P = 0.01, respectively, versus PAK recipients). Short-term pancreas graft survival rates were similar between the two groups: at 1 year posttransplant, 78.0% for SPK recipients and 77.9% for PAK recipients (P = not significant). By 3 years, however, pancreas graft survival differed between the two groups (74.1% for SPK and 61.7% for PAK recipients), although this did not quite reach statistical significance (P = 0.15). This difference in graft survival seemed to be due to increased immunologic losses for PAK recipients: at 3 years posttransplant, the incidence of immunologic graft loss was 16.2% for PAK versus 5.2% for SPK recipients (P = 0.01). Kidney graft survival rates were, however, better for PAK recipients. At 3 years after their kidney transplant, kidney graft survival rates were 83.6% for SPK and 94.6% for PAK recipients (P = 0.001). The mean waiting time to receive the pancreas transplant was 244 days for SPK and 167 days for PAK recipients (P = 0.001). CONCLUSIONS: PAK transplants are a viable option for uremic diabetics. While long-term pancreas graft results are slightly inferior to SPK transplants, the advantages of PAK transplants include the possibility of a preemptive living donor kidney transplant, better long-term kidney graft survival, significantly decreased waiting times, and decreased surgical complication rates. Use of a living donor for the kidney transplant expands the donor pool. Improvements in immunosuppressive regimens will hopefully eliminate some of the difference in long-term pancreas graft survival between SPK and PAK transplants.

Peri-operative cardiac morbidity in kidney transplant recipients: incidence and risk factors.

BACKGROUND: Renal transplant recipients are known to be at increased risk for developing cardiac disease. In both general and peripheral vascular surgery, pre-operative risk stratification (and intervention when indicated) has decreased the incidence of peri-operative cardiac complications. In this study, we set out to identify subsets of patients at high risk for peri-operative cardiac complications after a renal transplant. METHODS: We retrospectively reviewed the records of 2694 adult renal transplants performed at the University of Minnesota between January 1, 1985 and December 31, 1998. We determined the incidence of peri-operative (within 30 d post-transplant) cardiac complications, including myocardial infarction (MI). Risk factors for the development of these complications were determined by multivariate analysis. RESULTS: We found 163 peri-operative cardiac complications, for an overall incidence of 6.1%. Specific cardiac complications included MI (n=43, 1.6%), arrhythmia (n=74, 2.7%), angina (n=31, 1.2%), cardiac arrest (n=13, 0.5%), and congestive heart failure (n= 2, 0.1%). By multivariate analysis, significant risk factors for any cardiac complication were age> or =50 yr (relative risk (RR)=3.0, p=0.0001) and pre-transplant cardiac disease (RR=3.3, p=0.0001). Not significant were diabetes mellitus (DM), cadaver donor source, pre-transplant dialysis, a history of smoking, and hypertension. Significant risk factors for peri-operative MI were age> or =50 yr, pre-existing cardiac disease, and DM. Diabetic patients with pre-existing cardiac disease were at especially high risk for peri-operative cardiac events. CONCLUSIONS: Patients>50 yr and those with pre-existing cardiac disease, especially if diabetic, are at significantly increased risk for developing peri-operative cardiac complications after a renal transplant. Such patients require aggressive pre-operative investigations, which may include coronary angiography, to decrease the risk of post-transplant complications.

Kidney retransplants after initial graft loss to vascular thrombosis.

BACKGROUND: Vascular thrombosis early after a kidney transplant is an infrequent but devastating complication. Often, no cause is found. These recipients are generally felt to be good candidates for a retransplant. However, their ideal care at the time of the retransplant and their outcomes have not been well documented. We studied outcomes in 16 retransplant recipients who had lost their first graft early posttransplant (< 1 month) to vascular thrombosis. METHODS: Of 2,003 kidney transplants between I January 1984 and 30 September 1998, we identified 32 recipients who had lost their first graft early posttransplant to vascular thrombosis. Of these 32 recipients, 16 were subsequently retransplanted and detailed chart reviews were done. RESULTS: Of the 16 retransplant recipients, 12 lost their first graft to renal vein thrombosis and 4 to renal artery thrombosis. Thrombosis generally occurred early (mean, 3.6 d). Five recipients underwent a complete hematologic workup to rule out a thrombophilic disorder before their retransplant: 4 had a positive result (presence of antiphospholipid antibodies, n = 3; increased homocysteine levels, n = 1). These 4 recipients, along with 1 other recipient who had a strong family history of thrombosis, underwent thrombosis prophylaxis at the time of their retransplant. Prophylaxis consisted of low-dose heparin for the first 3-5 d posttransplant, followed by acetylsalicylic acid or Coumadin. Of the 16 retransplant recipients, none developed thrombosis. Of the 5 who underwent thrombosis prophylaxis, none had significant bleeding complications. At a mean follow-up of 5.4 yr, 10 (63%) recipients have functioning grafts. Causes of graft loss in the remaining 6 recipients were death with function (n = 5, 31%) and acute rejection (n = 1.6%). Graft and patient survival rates after these 16 retransplants were equivalent to results after primary transplants. The incidence of acute and chronic rejection was also no different (p = ns). CONCLUSION: Vascular thrombosis in the absence of obvious technical factors should prompt a workup for a thrombophilic disorder before a retransplant. Recipients with an identified disorder should undergo prophylaxis at the time of the retransplant. Results in these retransplant recipients are equivalent to those seen in primary transplant recipients.

Are wound complications after a kidney transplant more common with modern immunosuppression?

BACKGROUND: The most common surgical complication after a kidney transplant is likely related to the wound. The purpose of this analysis was to determine the incidence of, and risk factors for, wound complications (e.g., infections, hernias) in kidney recipients and to assess whether newer immunosuppressive drugs increase the risk for such complications. METHODS: Between January 1, 1984 and September 30, 1998, we performed 2013 adult kidney transplants. Of these 2013 recipients, 97 (4.8%) developed either a superficial or a deep wound infection. Additionally, 73 (3.6%) recipients developed either a fascial dehiscence or a hernia of the wound. We used univariate and multivariate techniques to determine significant risk factors and outcomes. RESULTS: Mean time to development of a superficial infection (defined as located above the fascia) was 11.9 days posttransplant; to development of a deep infection (defined as located below the fascia), 39.2 days; and to development of a hernia or fascial dehiscence, 12.8 months. By multivariate analysis, the most significant risk factor for a superficial or deep wound infection was obesity (defined as body mass index>30 kg/m2) (RR=4.4, P=0.0001). Other significant risk factors were a urine leak posttransplant, any reoperation through the transplant incision, diabetes, and the use of mycophenolate mofetil (MMF) (vs. azathioprine) for maintenance immunosuppression (RR=2.43, P=0.0001). Significant risk factors for a hernia or fascial dehiscence were any reoperation through the transplant incision, increased recipient age, obesity, and the use of MMF (vs. azathioprine) for maintenance immunosuppression (RR=3.54, P=0.0004). Use of antibody induction and treatment for acute rejection were not significant risk factors for either infections or hernias. Death-censored graft survival was lower in recipients who developed a wound infection (vs. those who did not); it was not lower in recipients who developed an incisional hernia or facial dehiscence (vs. those who did not). CONCLUSIONS: Despite immunosuppression including chronic steroids, the incidence of wound infections, incisional hernias, and fascial dehiscence is low in kidney recipients. As with other types of surgery, the main risk factors for postoperative complications are obesity, reoperation, and increased age. However, in kidney recipients, use of MMF (vs. azathioprine) is an additional risk factor -one that potentially could be altered, especially in high-risk recipients.

Split liver transplantation for two adult recipients: an initial experience.

The shortage of cadaver donor livers has been most severe for adult patients. Split liver transplantation is one method to expand the donor pool, but to have a significant impact on the waiting list, it needs to be applied for 2 adult recipients. We split livers from 6 cadaver donors, and transplanted 12 adult recipients. All splits were performed in situ with transection through the midplane of the liver, resulting in a right lobe and a left lobe graft. Mean donor age was 19.7 years; mean donor weight was 79.1 kg. Mean recipient age was 41.5 years. Mean weight of right lobe recipients was 89 kg; left lobe recipients, 60 kg. All donors were hemodynamically stable and had normal liver function tests. Mean operative time for the procurement was 7.4 h. Average blood loss during the transection of the liver was 490 mL. Mean GW/ RW ratio for all recipients was 0.87%; right lobe recipients, 0.86%; and left lobe recipients, 0.88%. With mean follow-up of 9.3 months, patient and graft survival rates were both 83.3%. There were 2 deaths: 1 after hepatic artery thrombosis (HAT) and subsequent multiorgan failure; the other after HAT, a liver retransplant, and subsequent gram-negative sepsis. The remaining 10 recipients are doing well. We observed no cases of primary nonfunction. Other complications included bile leak and/or stenosis (n = 3), bleeding from the Roux loop (n = 1), bleeding after percutaneous biopsy (n = 1), and incisional hernia (n = 1). In conclusion, split liver transplantation, using 1 cadaver liver for 2 adult recipients, can be performed successfully. Crucial to success is proper donor and recipient selection.

Rapid discontinuation of steroids in living donor kidney transplantation: a pilot study.

UNLABELLED: Steroids are associated with significant postoperative complications (hypertension, cosmetic changes, bone loss, hyperlipidemia, diabetes, and cataracts). Most develop early; in addition, late post-transplant steroid withdrawal in kidney transplant recipients has been associated with increased acute rejection (AR). To obviate these problems, we studied outcome of a protocol of rapid discontinuation of prednisone (RDS) (steroids stopped on POD6). Between November 1, 1999 and October 31, 2000, 51 adult living donor (LD) first transplant recipients (2 HLA-id, 28 non-id relative, 21 LURD) were immunosuppressed with thymoglobulin (1.25 mg/kg intraoperatively and then qdx4); prednisone (P) (500 mg methylprednisolone intraoperatively, 1 mg/kg x 1 day, 0.5 mg/kg x 2 days, 0.25 mg/kg x 2 days, then d/c); MMF, 1 g b.i.d.; and CSA, 4 mg/kg b.i.d. adjusted to achieve levels of 150-200 ng/mL (by HPLC). Exclusion criteria were delayed graft function or primary disease requiring P. Minimum follow-up was 5.5 months (range 5.5 to 17.5 months). Outcome was compared vs. previous cohorts of LD recipients immunosuppressed with P/AZA/CSA (n = 171) or P/MMF/CSA (n = 43) (both without antibody induction). RESULTS: For the RDS group, average CSA level (+/- S.E.) at 3 and 6 months was 190 +/- 12 and 180 +/- 9; avg. MMF dose, 1.7 +/- 0.1 g and 1.7 +/- 0.1 g. There was no significant difference in 6- and 12-month actuarial patient survival, graft survival and rejection-free graft survival between recipients on the RDS protocol vs. historical controls. For RDS recipients, actuarial 6- and 12-month rejection-free graft survival was 87%. Of the 51 RDS recipients, five (10%) have had AR (at 20 days, 1 month, 3 months, 3 months, and 3.5 months post-transplant). After treatment, all five were maintained on 5 mg P; there have been no second AR episodes. Two additional recipients were started on 5 mg P due to low white blood count (WBC) and low/no MMF. Of the 51 grafts, one has failed (death with function). Average serum Cr level (+/- S.E.) at 3 and 6 months for RDS recipients was 1.7 +/- 0.5 (NS vs. historical controls). CONCLUSION: For low-risk LD recipients, a kidney transplant with an RDS protocol does not increase risk of AR or graft loss. Future studies will need to be done to assess AR rates with an RDS protocol in cadaver transplant recipients and in recipients with delayed graft function.

Optimal timing for a pancreas transplant after a successful kidney transplant.

BACKGROUND: For certain uremic, diabetic patients, a sequential transplant of a kidney (usually from a living donor) followed by a cadaver pancreas has become an attractive option. But how long to wait after the kidney transplant before proceeding with a pancreas transplant is unclear. We studied outcomes in recipients of a pancreas at varying times after a kidney to determine the optimal timing for the second transplant. METHODS: We compared pancreas after kidney (PAK) transplants performed early (< or =4 months) and late (>4 months) after the kidney transplant to determine any significant differences in surgical complications or outcomes between the two groups. RESULTS: Between January 1, 1994, and September 30, 1998, we performed 123 cadaver PAK transplants. Of these, 25 (20%) were early and 98 (80%) were late. Characteristics of the two recipient groups were similar. We found no significant differences in outcome between the two groups. The incidence of surgical complications (bleeding, leaks, thrombosis, infections) and of opportunistic infections (such as cytomegalovirus) did not significantly differ between the two groups. Graft and patient survival rates were also equivalent (P=NS). The incidence of acute rejection by 3 months posttransplant was 20% in both groups. CONCLUSION: The timing of the pancreas transplant for PAK recipients does not seem to influence outcome. As long as an acceptable organ is available and the recipient is clinically stable, a PAK transplant can be performed relatively soon after the kidney transplant.