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Biomedical subjects

D R Grant

Publications and source records attributed to D R Grant.

At least 55 records · Page 3Linked to original sources
PubMed1993

[Technique to minimize the incidence of hepatic artery thrombosis in pediatric liver transplantation].

Hepatic artery thrombosis is a life-threatening complication after pediatric liver transplantation. We reviewed our experience in 62 children who received 72 liver transplant (69 whole grafts and 3 reduced-size grafts) between January 1984 and December 1991. They ranged in age from 6 months to 16 years (mean 5.8 years). Fifteen children (22%) were under 2 years and 10 patients (14%) were between 2 and 5 years. Forty-eight grafts in older children (age: 1-16 years, x = 7 years had an anastomosis between the donor hepatic/celiac artery and the recipient hepatic of splenic artery (A-A). Three thromboses occurred in this group for an incidence of 6.2%. Two others types of arterial reconstruction were used in 24 children who were significantly younger (6-120 months, x = 47 months, p < 0.01). Eight grafts had an anastomosis between the donor celiac artery and the recipient aorta (A-Ao). No thromboses occurred in this group. Sixteen grafts were revascularized using a donor aortic conduit anastomosed to the recipient aorta (AC) with a 12.5% (2 to 16) incidence of thrombosis. The incidence of arterial thrombosis for the entire group was 6.9%. In conclusion, by using the recipient aorta for arterial reconstruction, a low incidence of hepatic artery thrombosis can be achieved even in the group of younger patients who are the highest risk for this complication.

Adolescent↗
PubMed1992

CT findings in patients with small-bowel transplants.

Orthotopic small-bowel transplantation procedures are being performed increasingly often worldwide. CT plays an important role in both the preoperative assessment and the postoperative care of these patients. This pictorial essay serves to acquaint radiologists with the CT findings related to small-bowel transplantation.

Abscess↗
PubMed1991

Mucosal iron in the control of iron absorption in a rat intestinal transplant model.

Isogeneic intestinal transplantation of iron-loaded and iron-deficient intestine into iron-deficient rats was performed in 20 Lewis rats to isolate the effect of intestinal mucosal iron on iron absorption. Rats were iron loaded with three weekly IM injections of 50 mg of iron dextran and were rendered iron deficient with an iron-deficient diet for 3 weeks. Iron status was assessed by hepatic and gut mucosal iron determination. Uptake and transfer of 59Fe-ascorbate was measured in an isolated perfused segment of transplanted intestine 48 hours after transplantation. The mean rate of uptake of 59Fe from an iron-loaded intestine (mean mucosal iron concentration, 7.97 +/- 2.02 mumol/g) was 431 +/- 27 nmol/30 min, and from an iron-deficient intestine (mean mucosal iron concentration, 1.35 +/- .84 mumol/g), 743 +/- 222 nmol/30 min (P less than 0.001). The mean transfer of 59Fe from the mucosal cell to the body through an iron-loaded intestine was 63 +/- 22 nmol/30 min, and through an iron-deficient intestine was 86 +/- 32 nmol/30 min (P less than 0.05). These results suggest that the gut mucosal iron concentration regulates the uptake and transfer of iron in the intestine.

Animals↗
PubMed1991

The cyclosporin-erythromycin interaction: impaired first pass metabolism in the pig.

1. The pharmacokinetic interaction between cyclosporin (CsA) and erythromycin has been studied in the weanling pig model. 2. Blood CsA and metabolite-1 (M1) concentrations were monitored by high performance liquid chromatography in portal, hepatic and jugular venus blood before and after treatment with erythromycin stearate for 7 days. 3. Erythromycin significantly increased maximum concentration (Cmax) and area under the concentration-time curve from 0 to 24 h (AUC) of CsA in the peripheral circulation. This was accompanied by a significant reduction in the hepatic extraction ratio calculated from portal and hepatic Cmax and AUC data. 4. The extraction ratio appears to be concentration-dependent in that values derived from Cmax (high concentrations) were greater than those from AUC (average concentrations). 5. Time to Cmax (tmax) and t1/2 of CsA were essentially unchanged and no significant changes were observed in peripheral M1 kinetics apart from a small increase in tmax. 6. The pharmacokinetic changes observed in the pig suggest that the CsA-erythromycin interaction is caused by inhibition of hepatic metabolism and the impact of inhibition is greatest during first-pass when CsA concentrations are at their highest.

Animals↗
PubMed1991

Transplantation of a donor liver with haemochromatosis: evidence against an inherited intrahepatic defect.

An iron loaded liver from a 40 year old man with occult haemochromatosis was transplanted into a 19 year old woman with acute liver failure secondary to a paracetamol overdose. Increased parenchymal hepatic iron was found in a liver specimen at biopsy undertaken because of mild rejection 30 days after transplantation. After transplantation the patient had two episodes of liver rejection confirmed by biopsy. The hepatic iron concentration fell from 161 mumol/g on day 30 after transplant to 26.5 mumol/g (normal less than 40) on day 210. Iron absorption, measured 45 days after transplant, was in the normal range at 12.4%. The rapid fall in hepatic iron and the normal iron absorption study result suggest that the genetic defect of haemochromatosis is not exclusively an intrahepatic defect.

Adult↗
PubMed1991

Human orthotopic small intestine transplantation: radiologic assessment.

The authors describe the postoperative anatomy and review the radiologic examinations of five patients who underwent orthotopic small intestine or combined orthotopic liver and small intestine transplantation. Mucosal thickening of the transplanted intestine was demonstrated on the first postoperative contrast material-enhanced images and was due to submucosal edema. This resolved within 2 weeks in the long-term survivors. Bowel peristalsis appeared normal as early as 31 days after transplantation. Contrast-enhanced examinations of the intestine were useful to exclude surgical complications such as anastomotic leaks or strictures, but were insensitive for biopsy-proved cytomegalovirus enteritis or rejection.

Adult↗
PubMed1991

Effect of portasystemic shunts on subsequent transplantation of the liver.

Portasystemic (PS) shunts have been regarded as a relative contraindication to hepatic transplantation (HT) because of the potential for increased technical difficulties during the transplant operation. We compared operative blood loss, morbidity and mortality in 27 patients with PS shunts and 147 patients with no shunts (NS) who underwent HT. The PS shunt group included 12 portocaval (PC), eight mesocaval, four central splenorenal and four distal splenorenal shunts. The PS shunt and NS groups were similar with respect to age, preoperative medical status and ABO blood group matching between donors and recipients. There were no significant differences in the mean (plus or minus S.D.) intraoperative blood transfusion (9.1 +/- 7.6 versus 9.2 +/- 11.0 units), mean (plus or minus S.D.) duration of anesthesia (8.1 +/- 1.4 versus 7.8 +/- 1.5 hours) and operative mortality (7 versus 11 per cent) between the PS shunt and NS groups, respectively. Complications of the biliary tract were significantly higher in the PS shunt group (22.0 versus 5.4 per cent, p less than 0.01) but they did not increase the mortality rate. We conclude that a prior PS shunt should not influence the decision to accept patients for HT. PS shunts remain a reasonable surgical option for patients with cirrhosis and variceal hemorrhage (refractory to sclerotherapy) who, by virtue of good hepatic function, do not merit immediate HT.

Actuarial Analysis↗
PubMed1990

The use of older donor livers for hepatic transplantation.

The function and outcome of liver grafts from "older" donors (more than 50 years old) were compared with grafts from younger donors (less than 50 years old). Of 184 consecutive liver transplants, 23 grafts were from older donors (50.2-65.3 years, mean 54.3 years). The liver preservation period was short, averaging less than 4 hr with the maximum under 8 hr for the older grafts. The majority of livers were preserved with Collins' solution. All transplants were performed using consistent methods that had proved to be successful over time. The medical status of the patients who received the older and younger grafts was similar but a higher percentage of older grafts were transplanted into ABO blood group--incompatible recipients. Graft function--as determined by peak aminotransferase levels, duration of prolonged prothrombin time, retransplantation rate within 30 days and incidence of primary nonfunction--was not significantly different in older versus younger grafts. Actual 30-day graft survival was 86.9% in the older grafts and 85.1% in the younger grafts. Actuarial 1-year graft and patient survival rates were 65.0% and 71.4%, respectively, in recipients of older grafts and 68.8% and 75.6%, respectively, in recipients of younger grafts. It is concluded that donor livers older than 50 years can be transplanted with the same success as younger livers provided that other generally accepted donor criteria are satisfied and the preservation period is short. The upper age limit for liver donation is not yet known.

Age Factors↗
PubMed1989

Biliary tract reconstruction in liver transplantation.

Refinements in biliary tract reconstruction and the frequent use of cholangiography have produced a marked decline in the number of deaths from biliary complications after liver transplantation. The authors' method of reconstruction differs from those of others in that it employs no stents or T tubes and retains the donor gallbladder, allowing access to the biliary tract for radiologic purposes in the post-transplant period. In a series of 161 consecutive liver transplants, the frequency of biliary complications was 13.6% (15 anastomotic and 7 gallbladder-related). Of three deaths that occurred in patients with biliary complications, one was due to the complication itself. A Roux-en-Y reconstruction with anastomosis to the donor duct was associated with the lowest anastomotic complication rate (2.2%). Upper abdominal surgery before transplantation, especially shunting, was a major risk factor for biliary complications.

Adolescent↗
PubMed1988

Liver transplantation: the University Hospital-Children's Hospital of Western Ontario experience.

Patients who currently benefit the most from liver transplantation are those with end-stage, non-malignant liver disease. Primary biliary cirrhosis and cirrhosis from chronic active hepatitis (hepatitis B negative) have been the most common indications in our experience. Overall survival rates in excess of 70% at 1 year are now common and those patients who live the first year have a very good prospect of long-term survival. Complete rehabilitation occurs in about 80% of survivors. Patients on life support systems before transplantation and those awaiting urgent retransplantation have the highest mortality rates. Modern anesthetic and surgical techniques have made the operation much safer and more straightforward. Biliary tract complications remain common, especially in patients with a history of previous upper abdominal surgery. Cyclosporine has had a major impact, but in the context of its use in combination with other immunosuppressive agents (antilymphocyte globulin, steroids, azathioprine and OKT3).

Actuarial Analysis↗
PubMed1987

Fine-needle aspiration cytology of neoplastic cysts of the pancreas.

Herein is reported the cytologic features of four cases of cystic neoplasms of the pancreas as seen in fine-needle aspirates. Cytologically, the cases fall into two distinct groups: mucinous cystic neoplasm and serous cystadenoma. The aspirates from the mucinous cystic neoplasms characteristically showed columnar mucus-secreting epithelial cells, some of which were arranged in a papilloglandular pattern, with abundant mucous material in the background. The aspirates from the serous cystadenoma yielded small sheets of cuboidal cells with small nuclei and clear cytoplasm, without a background of mucous material. This cytologic division corresponds closely to the histologic classification proposed by Compagno and Oertel and hence is of prognostic and therapeutic value. The diagnostic challenges confronted by the cytopathologist are (1) to differentiate neoplastic cysts from the inflammatory pseudocysts; (2) to differentiate neoplastic epithelium from the normal epithelium of the bowel and pancreatic ducts; and (3) to differentiate mucinous cystic neoplasms from serous cystadenomas.

Adult↗
PubMed1987

Liver transplantation without venous bypass.

Fifty consecutive orthotopic liver transplants were performed without venous bypass in 41 recipients. Seven patients were transplanted twice and one patient received 3 transplants. The average age of the recipients was 37 years. The commonest indications for transplantation were primary biliary cirrhosis and cirrhosis from chronic active hepatitis. Fifty-eight percent of the recipients had undergone previous upper abdominal surgery. During the anhepatic period systolic blood pressure decreased by 21% to an average of 98 mm. of mercury. Cardiac output decreased by 52% to a mean (+/- SEM) of 3.89 +/- 0.21 L/min., and there was a doubling of the systemic vascular resistance. The hemodynamic alterations promptly returned to preclamping levels following hepatic revascularization. The average intraoperative transfusion requirements were 13 units of packed red blood cells, 9.6 units of platelets, 14.5 units of plasma and 6.6 L of crystalloid. Patients with previous surgery and retransplants required an average of 13 and 17 units of packed red blood cells, respectively. There was no deterioration in renal function in the postoperative period and no patient required hemodialysis. The 30 day survival was 87.8%. The 90-day and one-year actuarial survival is 80.5% and 68.8%, respectively. It is concluded that venous bypass is not necessary as a routine in orthotopic liver transplantation.

Adolescent↗
PubMed1986

Loop ileostomy for anorectal Crohn's disease.

The treatment of symptomatic Crohn's disease of the anorectum can be challenging. Medical therapy may fail and local surgery may be complicated by delayed healing or incontinence. The authors report the clinical course of 12 patients with this condition treated by fecal diversion with a loop ileostomy. Seven patients had a rectovaginal fistula. At the time of review, one of them had restored intestinal continuity following successful fistula repair, three had minimal or no symptoms, one had an active perianal fistula after closure of the ileostomy and two had undergone a proctocolectomy for recurrent symptoms. Five patients with Crohn's proctitis or anorectal sepsis were treated by loop ileostomy. One was asymptomatic, one had recurrent symptoms and three underwent a proctocolectomy. From their experience the authors conclude that construction of a loop ileostomy will temporarily improve the symptoms of anorectal Crohn's disease. Fecal diversion does not appear to alter the long-term course of the disease, and successful restoration of intestinal continuity is uncommon.

Adult↗
PubMed1985

Experimental low colorectal anastomosis.

The authors evaluated a side-to-end colorectal anastomosis carried out by the abdominoperineal approach, in which opening of the mucosal layer of the colon, and therefore the lumen, is delayed for 4 days. This technique was compared to transabdominal end-to-end anastomosis performed as low as possible, using the circular stapler and hand-sewing with a one-layer technique. Experimental end-to-end stapled and hand-sewn anastomoses were performed randomly in 24 female mongrel dogs. The operating time was similar for each group. Anastomoses were examined for leaks at 7 to 10 days digitally and by roentgenography after barium enema. At sacrifice 14 days after anastomosis, measurements were made of bursting strength and the distance of anastomoses from the anus. The degree of inflammation was evaluated histologically. There were three leaks in the hand-sewn anastomoses and none in the experimental end-to-end stapled anastomoses. The mean bursting strength was similar for all three techniques. The mean distance from the anus was lowest for the experimental anastomoses. Inflammatory changes were least in the end-to-end stapled anastomoses. Two dogs in this group and one in the experimental group were incontinent postoperatively. The experimental anastomosis compares favourably to end-to-end stapled and hand-sewn anastomoses and may have some advantages for low anastomosis in man.

Animals↗