A Transplant-Specific Quality Initiative-Introducing TransQIP: A Joint Effort of the ASTS and ACS.

In an attempt to improve surgical quality in the field of transplantation, the American College of Surgeons (ACS) and American Society of Transplant Surgeons have initiated a national quality improvement program in transplantation. This transplant-specific quality improvement program, called TransQIP, has been built from the ground up by transplant surgeons and captures detailed information on donor and recipient factors as well as transplant-specific outcomes. It is built upon the existing ACS/National Surgical Quality Improvement Program infrastructure and is designed to capture 100% of liver and kidney transplants performed at participating sites. TransQIP has completed its alpha pilot and will embark upon its beta phase at approximately 30 centers in the spring of 2017. Going forward, we anticipate TransQIP will help satisfy Centers for Medicare and Medicaid Services requirements for a quality improvement program, surgeon requirements for maintenance of certification, and qualify as a clinical practice improvement activity under the Merit-Based Incentive Payment System. Most importantly, we believe TransQIP will provide insight into surgical outcomes in transplantation that will allow the field to provide better care to our patients.

Automated identification of abnormal infant movements from smart phone videos.

Cerebral palsy (CP) is the most common cause of physical disability during childhood, occurring at a rate of 2.1 per 1000 live births. Early diagnosis is key to improving functional outcomes for children with CP. The General Movements (GMs) Assessment has high predictive validity for the detection of CP and is routinely used in high-risk infants but only 50% of infants with CP have overt risk factors when they are born. The implementation of CP screening programs represents an important endeavour, but feasibility is limited by access to trained GMs assessors. To facilitate progress towards this goal, we report a deep-learning framework for automating the GMs Assessment. We acquired 503 videos captured by parents and caregivers at home of infants aged between 12- and 18-weeks term-corrected age using a dedicated smartphone app. Using a deep learning algorithm, we automatically labelled and tracked 18 key body points in each video. We designed a custom pipeline to adjust for camera movement and infant size and trained a second machine learning algorithm to predict GMs classification from body point movement. Our automated body point labelling approach achieved human-level accuracy (mean ± SD error of 3.7 ± 5.2% of infant length) compared to gold-standard human annotation. Using body point tracking data, our prediction model achieved a cross-validated area under the curve (mean ± S.D.) of 0.80 ± 0.08 in unseen test data for predicting expert GMs classification with a sensitivity of 76% ± 15% for abnormal GMs and a negative predictive value of 94% ± 3%. This work highlights the potential for automated GMs screening programs to detect abnormal movements in infants as early as three months term-corrected age using digital technologies.

Juvenile cataract in association with tuberous sclerosis complex.

BACKGROUND: Tuberous sclerosis complex (TSC) is an autosomal dominant genetic disorder characterized by benign hamartomas occurring in multiple organ systems including the brain, kidneys, heart, lungs, liver, skin, and the eyes. Typical retinal findings associated with TSC include astrocytic hamartoma and achromic patch. While rare cases of cataract occurring in the setting of TSC have been reported, this is the first analysis of a large series of individuals with TSC that aims to quantify the frequency of this finding and to describe its clinical and genetic associations. MATERIALS AND METHODS: This is a retrospective chart review of 244 patients from the Herscot Center for Tuberous Sclerosis Complex at the Massachusetts General Hospital who underwent complete ophthalmic examination. We describe the clinical and genetic findings in five individuals with TSC and juvenile cataract. RESULTS: Four of five cases (80%) were unilateral. The cataract was described as having an anterior subcapsular component in 3 of 5 cases (60%). Three individuals (60%) underwent lensectomy with intraocular lens (IOL) implant and two individuals (40%) were observed. Genetic testing revealed a known disease-causing mutation in TSC2 in 100% of cases. CONCLUSIONS: Recent evidence suggests that mTOR signaling may play a role in cataract formation which could explain the relatively high incidence of juvenile cataract in this population. Juvenile cataract is a potentially under-recognized ocular manifestation of TSC.

Facilitation of recovery by -methyl-p-tyrosine after lateral hypothalamic damage.

Rats with bilateral lateral hypothalamic lesions die of starvation in approximately 7 days after surgery. Rats that were treated with alpha-methyl-p-tyrosine for 3 days prior to lateral hypothalamic surgery spontaneously eat, drink, and gain weight after surgery. These data suggest that recovery of function after lateral hypothalamic damage involves denervation supersensitivity.

Determinants of discard of expanded criteria donor kidneys: impact of biopsy and machine perfusion.

We examined factors associated with expanded criteria donor (ECD) kidney discard. Scientific Registry of Transplant Recipients (SRTR)/Organ Procurement and Transplantation Network (OPTN) data were examined for donor factors using logistic regression to determine the adjusted odds ratio (AOR) of discard of kidneys recovered between October 1999 and June 2005. Logistic and Cox regression models were used to determine associations with delayed graft function (DGF) and graft failure. Of the 12,536 recovered ECD kidneys, 5139 (41%) were discarded. Both the performance of a biopsy (AOR = 1.21, p = 0.02) and the degree of glomerulosclerosis (GS) on biopsy were significantly associated with increased odds of discard. GS was not consistently associated with DGF or graft failure. The discard rate of pumped ECD kidneys was 29.7% versus 43.6% for unpumped (AOR = 0.52, p < 0.0001). Among pumped kidneys, those with resistances of 0.26-0.38 and >0.38 mmHg/mL/min were discarded more than those with resistances of 0.18-0.25 mmHg/mL/min (AOR = 2.5 and 7.9, respectively). Among ECD kidneys, pumped kidneys were less likely to have DGF (AOR = 0.59, p < 0.0001) but not graft failure (RR = 0.9, p = 0.27). Biopsy findings and machine perfusion are important correlates of ECD kidney discard; corresponding associations with graft failure require further study.

Nailfold capillary morphology in exfoliation syndrome.

PurposeThe purpose of the study was to investigate nailfold microvascular morphology in exfoliation syndrome with or without glaucoma (XFS/XFG) compared with primary open-angle glaucoma (POAG) and control subjects using nailfold capillary videomicroscopy.Patients and methodsWe used a JH-1004 capillaroscope to perform nailfold capillary videomicroscopy on the fourth and fifth digit of the non-dominant hand. We enrolled 56 XFS/XFG patients, 87 POAG patients, and 75 control subjects. Masked observers graded the videos for hemorrhages, avascular zones ≥200 microns (µm), and degree of microvascular tortuosity on a four-point subjective scale. Multivariable odds ratios, 95% confidence intervals and P-for trends for assessing the relation between morphological changes and POAG or XFS/XFG were obtained from logistic regression analyses. We also assessed this relation with XFS/XFG compared with POAG in multivariable models.ResultsAfter adjusting for multiple covariates, nailfold hemorrhages, avascular zones ≥200 µm, and higher degree of vascular tortuosity were more common in XFS/XFG vs controls (P-for trend ≤0.0001) and in POAG vs controls (P-for trend ≤0.01). For each 100 capillaries, the number of hemorrhages was similar (P-for trend=0.91) between XFS/XFG and POAG patients; however, there were more avascular zones per 100 capillaries with borderline significance (P-for trend=0.04) in the XFS/XFG group. XFS/XFG patients had more tortuosity than POAG patients; specifically, having a tortuosity score ≥1.5 was associated with a 4.4-fold increased odds of XFS/XFG (95% confidence interval: 1.5-13.3) relative to a tortuosity score <1.0 (P-for trend=0.005).ConclusionA high degree of nailfold capillary tortuosity is a distinct non-ocular feature associated with XFS/XFG compared with either POAG or controls.

Selective use of expanded criteria donors for renal transplantation with good results.

Increasing demand for renal transplants has stimulated expanded criteria for the use of deceased donors. Recently an official category of "Expanded Criteria Donors" (ECD) was designated by UNOS. This category included any deceased donor (1) greater than age 60 years or (2) age 50 to 59 years with any two of: (a) creatinine greater than 1.5 mg/dL (b) cerebrovascular accident cause of death, or (c) hypertension history. It has been anticipated that at 3 years, 70% of ECD kidneys with serum creatinine greater than 1.5 would be lost. We reviewed our experience with the use of this type of kidney prior to the era of officially designated ECD. Survival rates and serum creatinines were compared to standard criteria donor recipients for the same time period whose donor was greater than 50 years of age and correlated with biopsies. From 1996 to 2003, 341 deceased donor kidneys were transplanted at our center. Of these, 37 were ECD kidneys and 46 were standard criteria donors kidneys. Four pretransplant biopsies had greater than 20% sclerosed glomeruli. Four donors had 0% to 25% arteriosclerosis pretransplant; on postperfusion biopsy, eight had 0% to 25% arteriosclerosis, while three had 25% to 50%. The mean donor age was 61 years; mean recipient age was 54 years; recipient sex was 57% male, and 54% of the recipients were African-American. At 1, 2, and 3 years posttransplant, there was no significant difference between the two groups in serum creatinine, graft survival, or patient survival. Despite using ECD donors, good long-term function can be obtained, particularly if selectivity is exercised.

The breast cancer-associated MUC1 gene generates both a receptor and its cognate binding protein.

MUC1 proteins, some of which contain a mucin-like domain and others lacking this region, can be generated from the human breast cancer-associated MUC1 gene by alternative splicing. The MUC1/Y isoform is devoid of the mucin domain and is a cell membrane protein that undergoes transphosphorylation on both serine and tyrosine residues. We have identified cognate binding proteins that specifically interact with the extracellular domain of MUC1/Y. Coimmunoprecipitation analyses clearly revealed the presence of complexes composed of MUC1/Y and its cognate binding proteins in primary breast tumor tissue. MUC1/Y-expressing mammary tumor cells can be specifically targeted, in vivo, with the labeled cognate binding protein. The k(D) of MUC1/Y for its binding proteins was estimated as 1.2 nM. The MUC1/Y binding proteins are also derived from the MUC1 gene and represent the secreted mucin-like polymorphic MUC1 proteins MUC1/SEC and MUC1/REP, which contain a tandem repeat array. Whereas nonposttranslationally modified MUC1/Y bound efficiently to MUC1/SEC, the latter mucin-like protein had to be posttranslationally modified in a cell-type specific manner to bind MUC1/Y. The interaction of MUC1/Y with MUC1/SEC has important biological functional correlates: (a) it induces MUC1/Y phosphorylation; and (b) it has a pronounced effect on cell morphology. These findings suggest that MUC1/Y and MUC1/SEC form an active receptor/ cognate binding protein complex that can elicit cellular responses. The proteins comprising this complex are, thus, generated by alternative splicing from one and the same gene, namely the MUC1 gene.

Fas activation reduces neutrophil adhesion to endothelial cells.

Polymorphonuclear neutrophils (PMN) express apoptotic markers and lose effector functions including adhesion, chemotaxis, and phagocytosis when cultured overnight. Although the loss of function correlates with apoptosis, it is not clear if functions are lost before an early marker of apoptosis, the display of phosphatidylserine (PS), targets PMN for removal by phagocytic cells. To address this question, freshly isolated PMN were treated with Fas-activating antibodies to induce apoptosis rapidly. Early markers of apoptosis and PMA-stimulated adhesion to endothelial cells were measured. After 1 h of Fas exposure, only 16% PMN had externalized PS. In contrast, Fas activation reduced PMA-stimulated adhesion between 68 and 27% depending on PMA concentration. The loss of adhesion was accompanied by a reduction in beta2 integrin expression and receptor clustering. These results indicate that the Fas-induced loss of adhesion may precede PS externalization and could limit participation in the inflammatory response before PS externalization targets PMN for removal.

No-load sirolimus with tacrolimus and steroids is safe and effective in renal transplantation.

AIM: Basiliximab (BX) induction, tacrolimus (TAC), and steroids have sharply reduced acute cellular rejection at our institution. However, late graft loss has continued, for which sirolimus (SL) was introduced into the protocol. METHODS: From July 1, 2001 to December 31, 2003, 152 live donor (LD) renal transplant recipients received TAC (level 15 to 20 ng/mL) and steroids, with BX induction. One hundred twenty-two patients (Group 1) received SL (3 mg/d African-americans; 2 mg/d for others) starting on days 2 and 3. The SL level was adjusted to 8 to 10 ng/d, usually by weeks 3 to 4 posttransplant. The TAC doses were then progressively reduced. Records were reviewed for demographics, immunosuppressive drug levels, serum cholesterol and blood pressure, and complications. Graft and patient survival rates were calculated. Comparison was made to 53 LD recipients transplanted from July 1, 1998, to June 30, 2001 (Group 2) receiving BX, steroids and TAC, without SL. Recipients of deceased donor kidneys were excluded because of variability in kidney quality, ischemic time, and patient management. RESULTS: Demographics were similar between groups: African Americans, 25% to 35%; mean age 36 years; mean HLA mismatch 3.7. Wound problems and infection were minimal in both groups. Mean serum creatinine and cholesterol and systolic and diastolic blood pressure measured periodically up to 1 year were similar, as was the incidence of rejection. In 25% of patients, SL was discontinued. CONCLUSIONS: Gradual introduction of SL appears to be associated with minimal wound problems. With more aggressive reduction in TAC, better renal function, and better long-term graft survival may be attainable. We currently lower TAC levels to 5 ng/mL by 3 months.

Evaluation of a multivariate model predicting noncompliance with medication regimens among renal transplant patients.

BACKGROUND: Because noncompliance with medication regimens is a major cause of renal allograft failure, we evaluated the stability over time of two logistic regression models (sets of variables) that predict noncompliance with immunosuppressive regimens. METHODS: Models were based on questionnaire data from 1402 patients (all over 18, receiving cyclosporine or a cyclosporine-like replacement drug, and with a functioning renal graft). The same questionnaire was completed by a subset of 548 (39.1%) patients approximately 18 months later. The goodness of fit of each model to the new data set was tested. RESULTS: The noncompliance logistic regression model including patient beliefs as well as patient and transplant characteristics was an excellent fit to the second data set. A noncompliance model composed of only patient and transplant characteristics fit the new data set less well. CONCLUSIONS: Clinicians and educators need to take explicit account of renal transplant patients' attitudes when evaluating risks of noncompliance and when developing interventions and educational programs to minimize noncompliance.

Compliance and noncompliance in patients with a functioning renal transplant: a multicenter study.

BACKGROUND: Noncompliance with medication is a major cause of renal allograft failure among adult renal transplant patients. We summarize previous studies of noncompliance and report results of a large, multicenter survey designed to identify variables that (1) affect the likelihood of compliance with immunosuppressive medication regimens and (2) distinguish among noncompliant patients. METHODS: Questionnaires were distributed to 2500 patients at 56 U.S. transplant centers. Compliance was determined by patient responses to questions concerning whether, within the previous 4 weeks, one or more doses of immunosuppressive medications had been missed. Independent variables included patient and transplant characteristics, memories of dialysis, posttransplant symptoms and beliefs, and beliefs concerning the efficacy and importance of immunosuppressants. RESULTS: The incidence of noncompliance reported by the 1402 respondents was 22.4%. A logistic regression model that included age, occupation, time since transplant, and three medication-related beliefs was most predictive of the likelihood of compliance. Donor type and histories of diabetes and of infection entered the multivariate model when belief-related variables were excluded. Cluster analyses identified three distinct profiles of noncompliers: accidental noncompliers, invulnerables, and decisive noncompliers. CONCLUSIONS: Results of this study, which included nearly three times more patients than the largest previously reported study, can be used by clinicians to identify patients likely to become noncompliant, by researchers to develop randomized, prospective clinical trials of interventions designed to increase compliance, and by educators to tailor patient education programs.

Transitional epithelial lesions of the ureter in renal transplant rejection.

The spectrum of ureteric lesions of human renal allografts, long attributed exclusively to postsurgical complications such as ischemia, has recently been shown to include the types of rejection seen in the kidney. Since the rejected ureter also exhibits transitional epithelial lesions that may impact on renal and ureteral function, we studied, by light, immunohistochemical, immunofluorescent, and electron microscopic techniques, ureters of 65 irreversibly rejected kidneys. Seven unused cadaver kidneys served as controls. Urothelial lesions, noticed in 57 of 65 ureters (88%), ranged from minimal basal vacuolization to complete sloughing with or without necrosis of the epithelial lining. Epithelial exfoliation was noticed in 31 cases (54.4%), and basal vacuolization, severe enough to produce cleavage of the epithelial junctions and thus create bullae, was noticed in 21 cases (36.8%). Immunofluorescent and immunoperoxidase stains, performed in 16 cases, were all positive for immunoglobulins but yielded varied results ranging from granular to linear staining, particularly in the region of the basal cells and the basement membrane. Electron microscopic findings confirmed the light microscopic alterations. By contrast, control ureters showed no lesions. Urothelial ureteric lesions might impede ureteral functions and result in obstruction or infection, thus compounding the consequences of renal allograft rejection. Moreover, elucidation of the pathophysiology of the process will advance the understanding of various cutaneous and transitional epithelial autoimmune conditions.

Primary intestinal posttransplant T-cell lymphoma.

There have been only five reported cases of primary posttransplant T-cell lymphoma. We report the first case associated with the use of sirolimus (Rapamycin, Wyeth-Ayerst, Philadelphia, PA). The patient, receiving prednisone, cyclosporine, and sirolimus treatment, developed ascites, diarrhea, and weight loss 7 months after his second renal transplant. Tissue obtained at laparotomy established the diagnosis of primary T-cell lymphoma. Latent membrane protein-1 for Epstein-Barr virus was negative, but in-site hybridization test for Epstein-Barr-encoded RNA was positive. Despite aggressive chemotherapy, the patient died 8 months posttransplant. This is the sixth reported case of primary intestinal posttransplant T-cell lymphoma, but it is the first case associated with the use of sirolimus. The incidence of posttransplant lymphoproliferative disease in patients receiving sirolimus should be studied.

Prevalence of asymptomatic cholelithiasis and risk of acute cholecystitis after kidney transplantation.

Prophylactic cholecystectomy for asymptomatic cholelithiasis is sometimes required before transplantation. However, there is little indication in the literature that transplant recipients are at any greater risk than individuals in the general population. Between January 1990 and December 1993, 211 renal transplant recipients underwent duplex sonography. All were asymptomatic. Twenty-one had positive findings: gallstones were found in 15 patients (7.11%) and sludge was found in 6 (2.84%). Of gallstone patients, seven (3%) were men and eight (4%) were women. One gallstone patient also had diabetes mellitus. The mean age by gender of the patients with calculi was 54 years for men and 38 years for women. Thirteen of the 15 patients with calculi (87%) have remained asymptomatic. Two patients (one diabetic) developed acute cholecystitis and underwent uncomplicated laparoscopic cholecystectomy. Patients with sludge were similar in gender and age to patients with gallstones; one patient had diabetes. No sludge patients became symptomatic. The incidence and morbidity of gallstones after kidney transplantation are low. Prophylactic cholecystectomy in asymptomatic patients before transplantation is not justified.

Effect of tacrolimus on hemodynamics and absorption of experimental small intestinal transplants.

We have previously reported the adverse effects of cyclosporine on small intestine transplant physiology. In this study, we report for the first time the effect of tacrolimus (FK) on graft intestinal blood flow and intramural distribution, vascular resistance, and absorptive function. Isogeneic small intestine transplantation was performed in Lewis rats. Animals were grouped based upon the following treatment schedules: no treatment for 1 week in group 1; 0.6 ml/kg/day i.m. polyethylene glycol (PEG) for 1 week in group 2; 2 mg/kg/day i.m. FK for 1 week in group 3; 0.6 ml/kg/day PEG for 1 week and then 0.3 ml/kg/day for 5 weeks in group 4; 2 mg/kg/day FK for 1 week and then 1 mg/kg/day for 5 weeks in group 5. Group 6 was the same as in group 5 but FK was withdrawn for 1 week prior to assessment. Maltose absorption was measured to evaluate graft absorptive function. Blood flow and its intramural distribution to mucosal and serosal/muscularis layers were determined using the radioactive microsphere technique. Perfusion pressure was measured to calculate vascular resistance. One week of FK administration in group 3 did not change graft hemodynamics and absorption significantly. Prolonged FK treatment up to 6 weeks in group 5 resulted in a significant increase in mucosal vascular resistance (71.0 +/- 9.6 versus 47.7 +/- 6.7 U/g, P<0.01) and significant decreases in mucosal blood flow (1.14 +/- O.15 versus 1.69 +/- 0.24 ml/g/min, P<0.01) and maltose absorption (30 min after loading. 155.4 +/- 26.9 versus 216.4 +/- 29.6, P<0.01; 60 min after loading: 172.9 +/- 24.5 versus 229.1 +/- 32.6 glucose mg/dl P<0.01). The serosal/muscularis layer remained relatively unaffected. Withdrawal of FK for 1 week after prolonged treatment in group 6 resulted in restorations of all parameters measured to normal ranges. We conclude that a short course of FK is safe, but prolonged FK administration has harmful effects on the hemodynamics and function of small intestinal transplants. Complete recovery is achieved when FK is discontinued.

Chronic renal allograft rejection: no response to mycophenolate mofetil.

BACKGROUND: Mycophenolate mofetil (MMF) has been previously shown to prevent functional deterioration in an experimental model of chronic renal allograft rejection. METHODS: In this retrospective case-control study, patients with chronic rejection who were receiving cyclosporine or tacrolimus and who had MMF added to their immunosuppressive regimen were compared with patients with chronic rejection who were not receiving MMF. Patients were matched for serum creatinine levels and transplant duration at the time MMF was begun. RESULTS: In the MMF group, the average dose of MMF was 1482 mg/day with an average duration of 19.3 months. Over 36 months, including 12 months before MMF and up to 24 months on MMF, there was no difference in serum creatinine levels between the two groups. Cyclosporine levels and dose were no different. CONCLUSIONS: In this small, retrospective, preliminary study, adding MMF to maintenance immunosuppression provided no clear benefit to renal allograft recipients with established chronic rejection. Larger prospective randomized studies are needed.

Evidence that zero antigen-matched cyclosporine-treated renal transplant recipients have graft survival equal to that of matched recipients. Reevaluation of points.

The value of HLA matching in cadaver renal transplantation (CRT) continues to be debated. It has recently been suggested that increased importance be given to HLA matching for the distribution of cadaver kidneys. Such a policy would add both delay and expense to CRT, which could be justified only by significantly improved results. The results of CRT in 252 cyclosporine treated adult patients transplanted at our institution from November 1984 to April 1989 were reviewed. Kidneys were initially transplanted into crossmatch-negative recipients based on waiting time, regardless of match. From October 1987, a points system, based on United Network for Organ Sharing (UNOS) criteria has been used. Eighty-four pts. with zero antigen match with their donors were compared with 168 pts. sharing 1-6 Ag. Actuarial graft and patient survival were determined by the cumulative life table method and compared using a log rank test. Our results indicated no statistically significant difference in graft survival because of better matching or mismatching. These findings are in keeping with our previously reported long-term results for non-CsA pts. Past predictions of improved graft survival based upon better matching at our institution have not fulfilled expectations, with the exception of 6 Ag matches. In conclusion, increased emphasis on HLA matching with fewer "points" for poorer matches does not appear justifiable.

Improved small intestinal preservation after lazaroid U74389G treatment and cold storage in University of Wisconsin solution.

The small intestine (SI) is highly sensitive to oxygen free radical-induced injury. The most common preservation solution, University of Wisconsin (UW) solution, does not adequately prevent free radical-induced injury. Lazaroids, and U74389G in particular, are a new class of compound that are potent inhibitors of superoxide-mediated lipid peroxidation. We studied the added influence of U74389G to 18-hr cold preservation of rat SI in UW solution. Three groups of rats were studied. In group 1, SI was excised and reperfused immediately. In group 2, SI was stored in UW solution at 4 degrees C for 18 hr. In group 3, U74389G was given to the SI graft before storage and again before reperfusion. Blood reperfusion of the grafts was achieved via connection to the superior mesenteric artery and portal vein of support rats. Functional recovery was assessed using a maltose tolerance test. Weight changes were calculated and histologic studies done. After 30 and 60 min of reperfusion, maltose uptake in group 3 was significantly better than that of the group 2, and returned to control levels. Significantly more tissue swelling was noted in group 3 over control, but the magnitude was less than that of group 2. Less transmural necrosis and villous blunting were noted in group 3 versus group 2; the appearance of the mucosa in group 3 approached that of group 1. We conclude that the use of U74389G treatment in addition to cold storage in UW solution improves recovery of graft function and minimizes morphologic damage to the small intestinal mucosa.

Percutaneous transluminal angioplasty. The procedure of choice in the hypertensive renal allograft recipient with renal artery stenosis.

A retrospective review of 547 renal transplants performed over a six-year period revealed allograft renovascular hypertension secondary to RTAS in 39 (7.1%) patients. Percutaneous transluminal angioplasty (PTA) resulted in immediate cure or improvement in 76% of the patients, increasing to 83% in patients with functioning kidneys at a mean follow-up period of 30 months (1-72 months). The renal artery stenosis (RTAS) was equally distributed between living-related and cadaver kidney recipients and did not appear to be more prevalent in end-to-end or end-to-side anastomoses. The blood pressures fell from pre-PTA levels of 167 +/- 22 mmHg systolic to 141 +/- 23.7 post-PTA and 102 +/- 11 mmHg diastolic pre-PTA to 88 +/- 12 mmHg post-PTA (P less than 0.01). Of 25 cured or improved patients, 24 are on significantly less hypertensive medication. Two patients died of causes unrelated to the PTA and only one patient lost a kidney because of the procedure. Compared with operation, PTA is a safer and more effective procedure for the initial treatment of RTAS.