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Biomedical subjects

T A Gonwa

Publications and source records attributed to T A Gonwa.

At least 19 recordsLinked to original sources
PubMed1997

Hepatic artery stenosis after liver transplantation--incidence, presentation, treatment, and long term outcome.

Little is known about hepatic artery (HA) patency and patient clinical course when the nonthrombosed HA has been revised. We undertook this study to evaluate the risk factors in the development of HA stenosis and to assess the impact of HA revision on the outcome. A total of 857 adult consecutive OLT in 780 patients performed over a 6-year period were studied. Patients who underwent revision of their nonthrombosed but stenotic HA were reviewed for patient/graft survival, method of HA revision, incidence of biliary strictures, and long-term HA patency. Overall 39 patients (5%) with 41 allografts underwent HA revision for stenosis. Median time to diagnosis was 100 days posttransplant (range 1-1220 days). HA flow at the time of OLT was found to be the only significant variable of an anastomotic stenosis. No risk factor could be identified for the graft HA stenosis. Treatment methods included resection of the stenotic segment with primary reanastomosis (n = 17), aortohepatic iliac artery graft (n = 11), interposition vein graft (n = 4), vein patch angioplasty (n = 2), interposition artery graft (n = 1), and percutaneous transluminal balloon angioplasty (n = 6). Postrevisional HA patency was demonstrated in 32 (78%) cases. At a median follow-up of 25 months, 26 patients (67%) were asymptomatic with good liver function. Nine patients had developed biliary strictures. Seven patients had undergone retransplantation and 8 patients had died. The actuarial patient and graft survivals at 4 years in the patients with revised HA were 65% and 56%, respectively. HA stenosis requiring revision is an infrequent occurrence after OLT. Long-term patency of the revised HA is good. Revision of the HA may help prevent biliary strictures and allow for good long-term graft function in the majority of patients.

Adult↗
PubMed1996

Influence of donor and recipient gender on the outcome of liver transplantation.

BACKGROUND: Gender is currently not a criterion in the allocation of scarce donor organs. The purpose of this study was to determine the effects of gender on patient and graft survival, incidence of rejection, and postoperative complications after orthotopic liver transplantation. METHODS: During a 10-year period, 1138 liver transplants were performed on 1010 adult patients at Baylor University Medical Center. In this study, 994 patients with at least 6 months of posttransplant follow-up were reviewed. The four combinations of gender match and mismatch included: group 1, donor female to recipient female (n=229); group 2, donor female to recipient male (n= 126); group 3, donor male to recipient female (n=247); and group 4, donor male to recipient male (n=392). These groups were evaluated for patient survival, graft survival, episodes of rejection, incidence of chronic rejection, and postoperative complications. RESULTS: All groups were similar with respect to recipient age, underlying medical condition, incidence of bacterial and viral infections, postoperative biliary complications, and the incidence of chronic rejection. Female recipients had the highest incidence of early rejection (0-6 months, 70%) compared with male recipients (60%, P<0.039). Postoperative vascular complication (10%) was highest in group 3 (P<0.01). The two-year graft survival rate for groups 1, 3, and 4 was 76.2%, 75.6%, and 73.5%, respectively. Group 2, donor female to recipient male, had a 2-year graft survival rate of 55.9% (P<0.0001). This finding is not explained by the incidence of early rejection. Chronic rejection does not appear to be contributory. The mean donor age for groups 1, 3, and 4 was 35.7, 25.8, and 30.4 years, respectively. The mean donor age for group 2 was slightly older, at 41.6 years (P<0.0001). This difference, while statistically significant, is of unknown clinical relevance. A multivariate analysis controlling for donor age confirmed the decreased graft and patient survival rates in the donor female to recipient male group. CONCLUSIONS: The decreased graft survival rate in male recipients of female livers warrants further study and may argue for modifying the current management of adult male liver transplant recipients.

Adenosine↗
PubMed1996

Alcohol use following liver transplantation for alcoholic cirrhosis.

Due to the significant increase in the number of patients with alcoholic liver cirrhosis being referred for liver transplantation, studies to determine recidivism rates and influential factors affecting those rates have become increasingly crucial. Between 12/85 and 12/91, 67 patients diagnosed with alcohol related end-stage liver disease underwent orthotopic liver transplantation at Baylor University Medical Center. A 3-8 year follow-up study was conducted wherein surviving patients were contacted by phone to evaluate subsequent alcohol consumption following transplantation (with the exception of two patients whose primary physicians were contacted). Of the 67 patients transplanted, 18 had expired, 7 were alive but unavailable, and 1 had been lost to follow-up. Of the remaining 41 patients interviewed, 21 had remained abstinent, while the other 20 had returned to some form of drinking. Of patients with less than 6 months of pretransplant abstinence, only 30% remained abstinent, while the other 70% had resumed drinking. Regarding patients with at least 6 months of pretransplant abstinence, 58% had remained abstinent, while the other 42% had resumed drinking. In both groups, nearly 1/3 of those who had admitted to posttransplant drinking reported themselves as again abstinent and recommitted to sobriety when interviewed. In conclusion, 49% of patients interviewed had resumed some type of drinking following transplantation-- however, this appears not to have affected compliance or survival potential. Only 2 (4.8%) of the 41 patients interviewed had returned to excessive drinking. Thus, our findings support the use of orthotopic liver transplantation for patients with alcohol related end-stage liver disease.

Adult↗
PubMed1996

Mycophenolate mofetil for maintenance therapy in kidney transplantation.

Mycophenolate mofetil (MMF) is a new immunosuppressive drug that selectively inhibits de novo purine synthesis. It has been tested in three large double-blind controlled trials for the prevention of rejection in renal transplant patients. These studies indicate that the use of MMF dramatically decreases the incidence of biopsy-proven rejection, the use of multiple courses of steroids for rejection, and the use of antilymphocyte preparations for treatment of rejection. The drug was well tolerated with an acceptable safety profile. The main side effects were gastrointestinal (nausea, vomiting, diarrhea), but seldom resulted in the cessation of drug therapy. Hematologic side effects similar to those with azathioprine occurred and were reversible. There was a slight increase in CMV-invasive disease with the use of MMF, but no deaths. Rates of malignancy were within published ranges for transplant recipients. Mycophenolate mofetil is a safe and efficacious drug for prevention of rejection in kidney transplant recipients.

Antilymphocyte Serum↗
PubMed1995

Quality of life improvements at one, two, and five years after liver transplantation.

We prospectively studied adult liver transplant (OLTX) recipients to evaluate the effect of OLTX on quality of life (QOL). Over an 8-year period, all adult patients undergoing OLTX at our institution were asked to complete a psychological questionnaire that probed broad facets of QOL. Patients seen for their 1, 2, and 5 or more-year post-OLTX visits were also asked to complete the form. Questions were then grouped by categories broadly highlighting self-image (SI), health perception (HP), ability to function (F), and ability to work (W). Questions ranged from demographic and occupational topics to symptom distress/frequency, activities of daily living, and the impact of health on daily life. Numerical scores were assigned to each question, and added to derive scores on SI, HP, and F. Higher scores reflect better QOL. Employment data (W) were also compared, though not amenable to scoring. A total of 573 forms were completed (210 pretransplant, 150 at 1 year, 131 at 2 years, 79 at 5 years). All posttransplant scores were significantly higher than pretransplant ones (P < or = .0001, ANOVA). Scores at posttransplant time points were not significantly different from each other. Subscores of SI and HP revealed less symptom frequency and distress following OLTX (P < or = .0003) continuing to beyond 5 years. Health limitations on activities decreased both at 1 year post-OLTX and again at 2 years (P < or = .0001) and were sustained to beyond 5 years. Fewer people were working for pay at 1 year post-compared with pre-OLTX, but pre-OLTX levels of employment had been regained by the second year, continuing to increase to beyond 5 years. OLTX leads to improved QOL by the end of the first posttransplant year, sustained through the 5th posttransplant year and beyond. Self-image, functioning ability, and perception of health status were significantly improved. Ill health interference in daily life continues to decrease as OLTX becomes more remote. Employment suffers early after OLTX, but recovers by the second post-OLTX year and continues to increase long-term.

Female↗
PubMed1995

Impact of pretransplant renal function on survival after liver transplantation.

To determine the effect of pretransplant liver function on survival following orthotopic liver transplantation and to quantify the effects of cyclosporine administration on long-term renal function in patients undergoing liver transplant, we performed an analysis of a prospectively maintained database. Data from 569 consecutive patients undergoing liver transplantation alone who were treated with CsA for immunosuppression were used for this study. Actuarial graft and patient survival rates were calculated using Kaplan-Meier statistics. Glomerular filtration rates, serum creatinine, and the use of various immunosuppressives were analyzed for this study. The initial analysis demonstrated that patients presenting for liver transplant with hepatorenal syndrome have a significantly decreased acturial patient survival after liver transplant at 5 years compared with patients without hepatorenal syndrome (60% vs. 68%, P < 0.03). Patients with hepatorenal syndrome recovered their renal function after liver transplant. Patients who had hepatorenal syndrome were sicker and required longer stays in the intensive care unit, longer hospitalizations, and more dialysis treatments after transplantation compared with patients who did not have hepatorenal syndrome. The incidence of end-stage renal disease after liver transplantation in patients who had hepatorenal syndrome was 7%, compared with 2% in patients who did not have hepatorenal syndrome. To more fully examine the effect of pretransplant renal function on posttransplant survival, the non-hepatorenal syndrome patients were divided into quartiles depending upon their pretransplant renal function. The patients with the lowest pretransplant renal function had the same survival as the patients with the highest pretransplant renal function. In addition, there was no increased incidence of acute or chronic rejection in any of the groups. The patients with the lower pretransplant renal function were treated with more azathioprine to maintain renal function and had a negligible decrease in glomerular filtration rate following transplant. Conversely, patients with the highest level of renal function pretransplant had a 40% decline in renal function in the first year, but maintained stable renal function up to 4 years after transplant. We conclude that pretransplant renal function other than hepato-renal syndrome has no effect on patient survival after orthotopic liver transplant. Renal function after liver transplant is stable after an initial decline, despite continued administration of CsA.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1995

A comparison of treatment with transjugular intrahepatic portosystemic shunt or distal splenorenal shunt in the management of variceal bleeding prior to liver transplantation.

Recurrent variceal bleeding in liver transplant candidates with end-stage liver disease can complicate or even prohibit a subsequent transplant procedure (OLT). Endoscopic sclerotherapy and medical therapy are considered as first-line management with surgical shunts reserved for refractory situations. Surgical shunts can be associated with a high mortality in this population and may complicate subsequent OLT. The transjugular intrahepatic portosystemic shunt (TIPS) has been recommended in these patients as a bridge to OLT. This is a new modality that has not been compared with previously established therapies such as the distal splenorenal shunt (DSRS). In this study we report our experience with 35 liver transplant recipients who had a previous TIPS (18 patients) or DSRS (17 patients) for variceal bleeding. The TIPS group had a significantly larger proportion of critically ill and Child-Pugh C patients. Mean operating time was more prolonged in the DSRS group (P = 0.014) but transfusion requirements were similar. Intraoperative portal vein blood flow measurements averaged 2132 +/- 725 ml/min in the TIPS group compared with 1120 +/- 351 ml/min in the DSRS group (P < 0.001). Arterial flows were similar. Mean ICU and hospital stays were similar. There were 3 hospital mortalities in the DSRS group and none in the TIPS group (P = 0.1). We conclude that TIPS is a valuable tool in the management of recurrent variceal bleeding prior to liver transplantation. Intraoperative hemodynamic measurements suggest a theoretical advantage with TIPS. In a group of patients with advanced liver disease we report an outcome that is similar to patients treated with DSRS prior to liver transplantation. The role of TIPS in the treatment of nontransplant candidates remains to be clarified.

Adult↗
PubMed1994

FK506 trough levels in whole blood and plasma in liver transplant recipients. Correlation with clinical events and side effects.

FK506 trough levels were measured by ELISA in paired whole-blood and plasma samples in 59 liver transplant recipients. Patients with nephrotoxicity had higher FK506 whole-blood and plasma levels (27.5 +/- 3.2 ng/ml and 1.44 +/- 0.14 ng/ml) than patients with stable liver function (15.2 +/- 2.1 ng/ml and 0.98 +/- 0.15 ng/ml, P < 0.05 and P < 0.01, respectively). Patients with acute rejection had FK506 whole-blood and plasma levels within the same range as patients with stable liver function. Patients with severe neurotoxicity had significantly higher FK506 whole-blood and plasma levels (31.3 +/- 6.8 ng/ml and 3.9 +/- 1.4 ng/ml) in comparison with patients with mild-to-moderate neurotoxicity (18.1 +/- 2.4 ng/ml and 1.1 +/- 0.13 ng/ml) (P = 0.048 and P < 0.001, respectively). Long-term use of FK506 was associated with a significant reduction in glomerular filtration rate at 1-year posttransplant in patients on primary FK506 treatment (33%, P < 0.001). The reduction in glomerular filtration rate correlated with the yearly mean FK506 plasma but not with whole-blood levels or FK506 dose. There was a correlation between FK506 whole-blood and plasma levels (r = 0.713, P < 0.001) but not between the levels (whole blood or plasma) and FK506 dose (mg/day or mg/kg/day). The mean FK506 whole-blood and plasma levels were 14.1 +/- 0.26 ng/ml and 0.96 +/- 0.75 ng/ml, respectively. There was a large intra- and interpatient variability in the ratio between whole-blood and plasma levels (range 1.0-73.5), with a mean ratio of 18.0 +/- 0.28 (+/- SEM). In conclusion, monitoring of FK506 trough levels is of importance to avoid nephro- and neurotoxicity, but monitoring is only of limited help to avoid acute rejection. Monitoring of FK506 levels in plasma seems to be superior to that in whole blood.

Adult↗
PubMed1993

OKT3 rescue for steroid-resistant rejection in adult liver transplantation.

The results of OKT3 use for steroid-resistant rejection rescue in adult liver transplantation were analyzed retrospectively from a single transplant center. Comparison was made with concurrent patients who had no rejection (NR) or steroid-responsive rejections (SR). The records of 290 patients who underwent 323 liver transplants from April 1985 to December 1989 were examined. The first technically successful grafts were used for this analysis (265 grafts). Follow-up was a minimum of 1 year, or until death or loss of graft. All patients received triple-drug induction immunosuppression (CsA, Aza, steroids). Initial rejection was treated with 1 g methylprednisolone bolus i.v., followed by a 5-day taper of steroids from 200 mg to 20 mg. No rejection occurred in 108 (40.8%) and SR in 86 (32.4%), and OKT3 was given for persistent rejection in 71 (26.8%). The age, sex distribution, mean follow-up, and preoperative status were similar in all three groups. The preoperative diagnoses were similar, except for fulminant liver failure, in which 19 of 20 patients experienced rejection (P < 0.0001). The median hospitalization stay was 37 days for OKT3, 27 days for SR, and 21 days for NR (P < 0.0001). The median ICU stay was similar in the three groups (OKT3, 4; SR, 4; NR, 3). Infections in the first 6 weeks, and in the period of 6 weeks to 1 year posttransplant, were of similar frequency for all three groups. By the Kaplan-Meier estimation, the graft and patient actuarial survival rates were comparable. At 1 year, the graft survival rate was 79.6% for NR, 79.8% for SR, and 67.6% for OKT3. The 1-year patient survival rate was 85.2% for NR, 83.7% for SR, and 84.5% for OKT3. Following treatment by OKT3, rejection was permanently reversed in 42 patients. A temporary response occurred in 12 patients, 16 patients failed to respond to OKT3, 2 patients died during therapy, and 6 of the nonresponders died within 12 months. Additional OKT3 treatment was attempted in 6 patients for persistent rejection within a 1-month interval from the previous OKT3 course. Of these 6, 4 developed lymphoproliferative disorder, and only 1 survived in response to drastic reduction of immunosuppression. In conclusion, OKT3 was effective as rescue therapy for adult liver transplant steroid-resistant rejection. Because of the associated morbidity and expense, OKT3 should be used in a selective fashion. Failure to respond to OKT3 is a serious complication, and should not be managed by prolonged or repeated courses, but rather by alternative means.

Adult↗
PubMed1993

Glomerular filtration rates in persons evaluated as living-related donors--are our standards too high?

We have retrospectively analyzed the glomerular filtration rate by 125-I iothalamate clearance and creatinine clearance in a group of 661 persons evaluated as potential kidney donors. The average GFR in this population is lower than that reported in previous studies and ranges from 102 +/- 15 and 114 +/- 17 ml/min for males and females age 21-30 to 84 +/- 13 and 79 +/- 15 ml/min for males and females age 51-60. Furthermore, there has been a gradual decrease in GFR in this population from 1970 to 1990 in both the entire population and in those under the age of 40. The cause of this drop is not apparent. These data can be utilized to determine the appropriateness of a potential donor for donation, and may indicate that our current standards are too high.

Adult↗
PubMed1993

Causes of late graft loss after liver transplantation.

The causes of graft loss in liver transplant recipients with a graft functioning for more than 1 year post-transplant were analyzed. Of 500 liver transplants in 434 patients, 362 grafts were functioning for more than 1 year. After 1 year, 42 grafts were later lost (11.6%). Thirty-three grafts were lost by death and 9 retransplants were done with 8 patients. Of the grafts lost by death, 12 had no evidence of dysfunction. The actuarial 2- and 5-year graft survival in liver transplantation recipients with functioning grafts for more than 1 year was 91 and 83%, respectively. The graft loss rate was 3.4 times higher during the 2nd year post-transplant than during 2-5 years post-transplant. The most common causes of graft loss were chronic rejection (26.2%), recurrent hepatitis (23.8%), arterial thrombosis/stenosis (11.9%) and recurrent malignancy (9.5%). No graft was lost from acute rejection. There was no difference in timing of the graft lost between the different causes. The pretransplant diagnosis of hepatitis B, chronic rejection, and malignancy was associated with the highest frequency of late graft lost. In conclusion, long-term graft survival is good after liver transplantation in patients with a functioning graft for more than 1 year. The main causes of graft loss were chronic rejection and recurrent hepatitis. Prevention and treatment for these conditions may further improve the results after liver transplantation.

Adolescent↗
PubMed1993

The kidney in liver transplantation.

Renal dysfunction often complicates the course of liver transplant recipients. Preoperative renal dysfunction, including hepatorenal syndrome (HRS) may be present. Assessment of renal function in the pretransplant patient with end-stage liver disease is fraught with pitfalls. Direct measurement of GFR by a method other than creatinine clearance is recommended wherever possible. Preoperative renal biopsy should also be considered in those patients with renal dysfunction in whom the diagnosis of HRS is not definite. With the routine use of veno venous bypass, renal perfusion is maintained and intraoperative events generally do not play a significant role in the development of postoperative dysfunction. Postoperatively immunosuppressive medications such as CsA or FK506 account for most of the renal dysfunction that is observed. Other factors such as graft dysfunction, sepsis, and nephrotoxic drugs may also participate in renal impairment. The exact mechanism of cyclosporine or FK506 nephrotoxicity remains unknown. In liver transplant recipients, no convincing therapeutic strategies exist to combat nephrotoxicity other than dose reduction of immunosuppressive therapy. Patients with HRS can be successfully treated by liver transplantation with recovery of renal function and with patient survival rates comparable to recipients without HRS, despite increased morbidity.

Cyclosporine↗