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T K Howard

Publications and source records attributed to T K Howard.

48 records · Page 3Linked to original sources
PubMed1995

Anomalous ureteral insertion in VATER syndrome complicating renal transplantation.

We report a renal transplantation with uretero-ureterostomy to a normal ureter in a patient with VATER syndrome who had agenesis of the ipsilateral kidney. Anomalous insertion of the native ureter into the ejeculatory duct was subsequently identified when his post-operative course was complicated by an ureteric leak and hydronephrosis. To our knowledge, this anomaly has not been previously reported. Transplant function is now excellent following temporary percutaneous nephrostomy. Contrast delineation of genito-urinary anatomy is recommended, before utilizing existing anatomical structures in the urinary tract, in patients with VATER syndrome.

Abnormalities, Multiple↗
PubMed1995

Evidence of preservation injury to bile ducts by bile salts in the pig and its prevention by infusions of hydrophilic bile salts.

Preservation injury to bile ducts is a serious problem in liver transplantation, especially when preservation exceeds 12 hours. The authors hypothesized that the injury was caused by contact of bile ducts with bile salts during cold preservation and might be preventable by infusion of more hydrophilic bile salts. Swine livers were harvested after intraportal infusions of saline (control), of the hydrophobic bile salt taurodeoxycholate, or of the hydrophilic bile salts tauroursodeoxycholate or dehydrocholate. The effect of infusing a combination of hydrophilic and hydrophobic bile acids was also studied. Bile samples were taken before and during the infusions. Then livers were perfused with UW solution, ducts were flushed retrograde with UW, and livers were stored at 0 to 1 degree C for 20 hours. Bile ducts were harvested after preservation, and coded microscopic slides of the specimens were examined by light microscopy. There was large variability in baseline bile salt concentration. Injury after preservation consisted of sloughing and pyknosis of surface and glandular epithelium. The histologic injury score determined after preservation was directly related to bile salt concentration in bile ducts at the time of flushing. During bile salt infusions, the infused bile salt replaced most or all of the other bile salts present in bile. Severe postpreservation injury of intrahepatic ducts occurred after taurodeoxycholate infusions, but injury was minimal when either of the two hydrophilic bile salts was infused. The mixture of bile acids produced intermediate results. Retrograde flushing with UW does not prevent injury to intrahepatic ducts. The authors conclude that the injury is caused by contact with bile salts, is dependent on bile salt concentration and composition, and is preventable.

Adenosine↗
PubMed1994

Selecting the donor liver: risk factors for poor function after orthotopic liver transplantation.

Initial poor function and primary nonfunction are important problems in clinical transplantation. The incidence of primary nonfunction is about 6% and that of initial poor function is about 15%. Grafts with initial poor function have a higher graft failure rate in the first 3 mo after transplantation. Severe steatosis and cold preservation in University of Wisconsin solution for over 30 hr will alone cause primary nonfunction. However, primary nonfunction is probably most often caused by the presence of multiple relative risk factors. The major donor-relative risk factors are moderate steatosis, cold preservation over 12 hr and donor age over 50 yr, whereas retransplantation, high (United Network of Organ Sharing class 4) medical status and kidney failure are recipient relative risk factors. The most important perioperative risk factor is warm ischemia time. Rates of primary nonfunction and initial poor function might be reduced by avoidance of combinations of risk factors. Several tests have been developed to predict primary nonfunction and initial poor function, but none is yet clinically efficient.

Adult↗
PubMed1993

The insulin-like growth factor 1 receptor gene is normally biallelically expressed in human juvenile tissue and tumours.

We have examined insulin-like growth factor 1 receptor (IGF1R) gene expression for evidence of imprinting in 15 informative patients with embryonal tumours. Biallelic expression was observed in all but one sample of normal juvenile kidney and liver, and in 9/10 associated Wilms' tumours, 3/3 hepatoblastomas and 2/2 adrenal tumours. A single patient with Beckwith-Wiedemann Syndrome (BWS) demonstrated monoallelic expression of the maternally derived IGF1R allele in normal kidney, associated Wilms' tumour and in peripheral blood lymphocytes. The observed biallelic expression of the IGF1R gene in all but one patient strongly suggests that the human gene is not normally imprinted.

Adrenal Gland Neoplasms↗
PubMed1990

The influence of preservation injury on rejection in the hepatic transplant recipient.

The records of 215 liver transplant recipients were reviewed and the degree of preservation injury was estimated by the initial aminotransferase levels. This was compared with the incidence of rejection found in the subsequent 30 days. Those with aspartate aminotransferase greater than 2000 U/L were classified as having severe preservation injury while those with ASAT less than 600 U/L were considered to have had minimal preservation injury. There were no significant differences between these groups in recipient age, sex, cold ischemia time, preoperative physical status, panel-reactive antibodies, or cytotoxic crossmatch. The solution used for organ preservation and the donor age were the only factors that were found to be significantly different between the groups. Older donors were more common in the severe preservation injury group. Severe preservation injury was found more frequently in grafts preserved in Eurocollins solution and the group with minimal preservation injury more frequently used Wisconsin solution. There was significantly more rejection seen in the severe preservation injury group (71%) than in the group without preservation injury (33%). Although there was more rejection in the severe preservation injury group, the rejections were not more severe as judged by the need for multiple courses of therapy or the need for OKT3. Recurrent rejection was also not more frequent in either group. Graft survival was worse in the severe preservation injury group, with a significant increase in early graft loss, but no difference in the frequency of chronic rejection. Recovery of graft function was also delayed in the preservation injury group.

Adenosine↗
PubMed1990

A comparison of UW with Eurocollins preservation solution in liver transplantation.

Fifty consecutive liver transplants were performed using livers perfused with and stored in University of Wisconsin preservation solution. These grafts were compared with the preceding 55 consecutive transplants performed using livers perfused and preserved with Eurocollins solution. The purpose of the study was to determine if organs preserved with UW solution functioned better after transplantation than organs preserved with Eurocollins. Extensive retrospective analysis of prospectively accumulated data included enzyme levels through 30 days, cost and length of hospital stay, blood product usage, and ischemia time. Average age of patients in the UW group was 47.1 years compared with 39.6 years in the EC group (P less than 0.05); cold ischemia time was 7.21 hr in the UW group compared with 5.21 in EC (P = 0.0001). Total bilirubin values were significantly lower on days 0-6 and day 14, but not day 30, in the UW group. Aspartate aminotransferase was significantly lower in the UW group on days 0-1, 3-6, and 14, but not on day 3 or day 30. Prothrombin times were significantly lower in the UW group across all times (days 0-6, 14, and 30). Intraoperative and postoperative use of packed red blood cells and fresh frozen plasma was lower in the UW group (P less than or equal to .05). Also, total hospital days, intensive care unit days, and hospital cost to the patient were lower in the UW group (P less than or equal to .05). A second analysis was done comparing only nonemergent transplants from both groups. These results confirmed the initial analysis of a longer cold ischemia time in the UW group (P less than 0.001), and improved enzyme values in the TBR, AST, and PT in the UW group (P less than 0.05). Also, hospital cost in the UW group was again lower (P less than 0.05). In this nonrandomized study, the cold ischemia time was increased but kept close to that of the control group. We conclude that UW solution is an improved donor liver preservation solution on the basis of improved enzyme values, decreased blood usage, shorter hospital stay, and lower hospital charges.

Adenosine↗
PubMed1990

Problematic vascular reconstruction in liver transplantation. Part II. Portovenous conduits.

Eight of 265 orthotopic liver transplant procedures performed at this institution since December 1984 have used venous conduits to reconstruct an occluded portal system and supply portal blood to the allograft. The factors mandating the use of these conduits were variable, and several reconstructive techniques were used. We present a series of patients with various conditions in which portal conduits were indicated and describe and illustrate the inherent technical considerations.

Anastomosis, Surgical↗