Biomedical subjects
Publications and source records attributed to R J Hall.
Cardiopulmonary bypass immediately post-partum could carry the risk of severe uterine bleeding. We report the case of a woman who successfully underwent emergency replacement of a thrombosed mitral prosthesis immediately after Caesarean section.
To examine the prognostic value of routine postinfarction exercise tests in young patients, exercise tests were carried out at 3 and 6 weeks and 18 months after infarction in 149 patients aged under 55 years at the time of the index infarction. The patients also had coronary angiography and left ventriculography a mean of 3 months after infarction. Three years after infarction, only two of the 149 patients have died, reinfarction occurred in only seven (4.7%) patients; unstable angina in four (3%) patients and coronary artery surgery was needed in 31 (20.8%) patients; 16 in the first, 10 in the second, and 5 in the third year of follow-up. Angina on exercise testing at 6 weeks was the only variable with any predictive value. Eighteen (38%) of the 47 patients with, compared to 12 (11.8%) of the 102 patients without, angina on exercise testing at 6 weeks had coronary surgery (less than 0.001). None of the other exercise variables reliably predicted death, or other complications, including coronary surgery. Ten (13.8%) of the 75 patients excluded from the study died during follow-up; six of them within 6 weeks of infarction. Four (67%) of these patients were excluded from the study because of heart failure. Therefore, the 3-year outcome in young survivors of a myocardial infarction is good and is not reliably predicted by exercise testing at 3 and 6 weeks or 18 months.
The development of late tricuspid regurgitation is an important complication of mitral valve surgery, as it is associated with a severe impairment of exercise capacity and a poor symptomatic outcome. The pathogenesis of this condition remains poorly defined, but it is usually attributable to a functional abnormality of the tricuspid valve. Whilst its development may indicate an increased afterload on the right heart as a consequence of persistent pulmonary hypertension, mitral prosthetic dysfunction, progressive aortic valve disease or left ventricular failure, late tricuspid regurgitation may also develop in the absence of these factors and then may reflect right ventricular dysfunction and/or a localized abnormality of the tricuspid anulus. Failure to recognize and correct tricuspid regurgitation at the time of initial surgery may also account for many cases of tricuspid regurgitation but its re-appearance following tricuspid annuloplasty is uncommon and usually reflects a failure of the mitral prosthesis. A reduction in the prevalence of late tricuspid regurgitation is an important objective in view of the high operative mortality and disappointing long term results associated with reoperation for tricuspid regurgitation. This may be best achieved through combining earlier mitral valve surgery with the accurate detection and liberal correction of accompanying tricuspid incompetence at the time of initial surgery.(ABSTRACT TRUNCATED AT 250 WORDS)
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There is a widely held but unsubstantiated belief that in infants with biliary atresia and coexisting polysplenia syndrome, the Kasai operation fails. An equally poor prognosis has been forecast for patients with this complex treated by liver transplantation. From 1975 to 1989, 16 of 131 infants with biliary atresia (12%) had one or more components of the polysplenia syndrome: polysplenia (8), intestinal malrotation (12), preduodenal portal vein (6), absent inferior vena cava (6), aberrant hepatic artery (4), or abdominal heterotaxia (4). Although technically more demanding, 12 of the 15 polysplenia patients achieved biliary drainage after operation. (One patient had exploration only, because of parental preference). Four children are alive; two are anicteric and well at ages 5 and 8 following Kasai's operation, and two by virtue of liver transplantation done at ages 4 and 7. Three of the five patients who had liver transplantation died. Acturial survival was 44% at 5 years, not significantly different from that of the 115 nonpolysplenia patients (48%). When associated with the constellation of anomalies known as the polysplenia syndrome, biliary atresia is most likely caused by an early (at approximately the fifth week) embryonic insult. The anomalies do not preclude successful biliary reconstruction using the Kasai procedure or successful liver transplantation.
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OBJECTIVE: To determine how severe tricuspid regurgitation influences exercise capacity and functional state in patients who have undergone successful mitral valve replacement for rheumatic mitral valve disease. DESIGN: 9 patients in whom clinically significant tricuspid regurgitation developed late after mitral valve replacement were compared with 9 patients with no clinical evidence of tricuspid regurgitation. The two groups were matched for preoperative clinical and haemodynamic variables. Patients were assessed by conventional echocardiography, Doppler echocardiography, and a maximal treadmill exercise test in which expired gas was monitored by mass spectrometry. SETTING: University Hospital of Wales, Cardiff. SUBJECTS: 18 patients who had been reviewed regularly since mitral valve replacement. MAIN OUTCOME MEASURE: Objective indices of exercise performance including exercise duration, maximal oxygen consumption, anaerobic threshold, and ventilatory response to exercise. RESULTS: Mitral valve prosthetic function was normal in all patients and estimated pulmonary artery systolic pressure and left ventricular function were similar in the two groups. Right ventricular diameter (median (range) 5.0 (4.3-5.6) v 3.7 (3.0-5.4) cm, p less than 0.01) and the incidence of paradoxical septal motion (9/9 v 3/9, p less than 0.01) were greater in the group with severe tricuspid regurgitation. Exercise performance--assessed by exercise duration (6.3 (5.0-10.7) v 12.7 (7.2-16.0) min, p less than 0.01), maximum oxygen consumption (11.2 (7.3-17.8) v 17.7 (11.8-21.4) ml min-1 kg-1, p less than 0.01), and anaerobic threshold (8.3 (4.6-11.4) v 0.7 (7.3-15.5) ml min-1 kg-1, p less than 0.05)--was significantly reduced in the group with severe tricuspid regurgitation. The ventilatory response to exercise was greater in patients with tricuspid regurgitation (minute ventilation at the same minute carbon dioxide production (41.0 (29.9-59.5) v 33.6 (26.8-39.3) l/min, p less than 0.01). CONCLUSIONS: Clinically significant tricuspid regurgitation may develop late after successful mitral valve replacement and in the absence of residual pulmonary hypertension, prosthetic dysfunction, or significant left ventricular impairment. Patients in whom severe tricuspid regurgitation developed had a considerable reduction in exercise capacity caused by an impaired cardiac output response to exercise and therefore experienced a poor functional outcome. The extent to which this was attributable to the tricuspid regurgitation itself or alternatively to the consequences of right ventricular dysfunction was not clear and requires further investigation.
Limited Doppler echocardiographic data are available regarding velocities and gradients across normally functioning St. Jude Medical valves in the aortic position. To establish a standard reference for Doppler characteristics of normal aortic St. Jude Medical prostheses, we recorded continuous-wave Doppler measurements of peak and mean velocities and peak and mean gradients in 180 patients with normally functioning St. Jude aortic valves. There were 119 men and 61 women in the study; the mean age was 57 years. Minimal valvular regurgitation was present in 56 patients (31 percent). Velocities and gradients were reported in five patient groups according to valve sizes of 19 mm, 21 mm, 23 mm, 25 mm, and 27 mm; the mean gradients were 16 +/- 6, 16 +/- 6, 14 +/- 5, 12 +/- 5, and 12 +/- 6, respectively. Differences in velocities and gradients among the five valve sizes were not statistically significant (p = 0.05). Velocities and gradients were also analyzed in three patient groups according to time intervals after valve replacement. The first group (n = 64) underwent Doppler evaluation one to seven days postoperatively (mean, six days); the second group (n = 60) was evaluated after 8 to 30 days postoperatively (mean, 12 days); and the third group (n = 56) was evaluated after more than 30 days postoperatively (mean, 691 days). There were no significant differences in measurements for the three groups.
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Anatomical abnormalities of the small bowel that cause intestinal stagnation result in bacterial overgrowth and a blind loop syndrome (BLS). Bacterial breakdown of bile salts and deamination of protein lead to malabsorption, steatorrhea, and fat-soluble vitamin deficiencies. Four children developed BLS as a complication of necrotizing enterocolitis, jejunal atresia, gastroschisis, and biliary atresia. BLS was suggested by abdominal pain, feculent vomiting, steatorrhea, and hypoalbuminemia. Dilated, stagnant bowel loops were demonstrated in each instance by upper gastrointestinal contrast study. Positive intestinal bacterial aspirates were confirmatory. Antibiotic treatment in two patients improved symptomatology but all children ultimately required surgery. Surgical procedures consisted of blind loop resection, intestinal plication, and catheterization of the bilioenteric conduit. All patients are now asymptomatic but one child suffers from parenteral nutrition-related cirrhosis and another requires chronic antibiotic therapy.
The Registry provides information about 904 children with biliary atresia from more than 100 institutions. There was a 1.4 to 1 female predominance; racial distribution was 62% caucasian, 20% black, 11% Hispanic, 4.2% asian, and 1.5% American Indian. Eight hundred sixteen (90%) underwent corrective surgery (median age at operation, 69 days). Intraoperatively, 70% had totally obliterated extrahepatic bile ducts, 22% had patency of the gallbladder and distal common duct, whereas only 8% had "correctable" biliary atresia (proximal duct patency). A variety of reconstructions were used, but the majority of patients had a Roux-en-Y portoenterostomy with or without exteriorization. Follow-up was available for 670 children (74%) with average length of follow-up of 5 years (range, 1 to 16 years). Five-year actuarial survival was 48% following Kasai's operation, but was less than 10% (at 3 years) if no operative correction was done. Survival was unaffected by sex, type of reconstruction, or cholangitis. Predictors of a bad outcome were (1) caucasian race; (2) operative age greater than 60 days; (3) presence of cirrhosis at initial biopsy; (4) totally nonpatent extrahepatic ducts; (5) absent ducts at the level of transection in the liver hilus; and (6) subsequent development of varices or ascites. Identification of factors predictive of the ultimate outcome provide a basis for either continued efforts with management of Kasai's operation or for early referral for liver transplantation.
The relative merits of noninvasive techniques in the assessment of valve stenosis were examined by comparing the results of clinical assessment by two independent clinicians, the cross-sectional echocardiogram and Doppler ultrasound using the results of cardiac catheterisation as reference in 58 patients with a total of 60 stenotic valve lesions. Doppler ultrasound was the most reliable technique; it was correct in 57 (95%) of the 60 lesions. Clinical assessment and cross sectional echocardiography were correct in 48 (80%), and 46 (77%) of the 60 lesions, respectively. In 7 instances 2 noninvasive assessments were wrong in the same patient but on no occasion were all 3 techniques misleading in the same patient. In 17 patients with severe mitral stenosis, clinical assessment Doppler ultrasound and cross-sectional echocardiography were correct in 14 (82%), 16 (94%) and 17 (100%) patients, respectively, whilst in the 4 patients with moderate mitral stenosis the corresponding figures were 3 (75%), 4 (100%) and 2 (50%). In mild mitral stenosis (3 patients), the clinical assessment was correct in 2 (67%) patients, Doppler ultrasound in 3 (100%) patients and cross-sectional echocardiography in 2 (67%) patients. In 22 patients with severe aortic stenosis, the clinical assessment and Doppler ultrasound were correct in every patient (100%), whilst the cross-sectional echocardiogram was correct in 18 (82%) patients. In 11 patients with moderate aortic stenosis, the clinical assessment was correct in only 5 (45%) patients, the cross-sectional echocardiogram in 5 (45%) patients and Doppler assessment in 9 (82%) patients.(ABSTRACT TRUNCATED AT 250 WORDS)
Five patients were encountered in whom agenesis either of the proximal extrahepatic biliary ducts (four patients) or total absence of the extrahepatic bile ducts and gall bladder (one patient) were evaluated. Jaundice was diagnosed from at birth to 3 weeks of age (average, 1.2 weeks of age) in these five patients. The patients' ages ranged from 2 to 8 weeks at the time of surgical exploration. Findings at surgery showed either absence of the entire extrahepatic biliary ducts or proximal bile duct remnants, no evidence of an inflammatory process, and no fibrous mass present at the portahepatis. Liver biopsy specimens showed histological evidence of cholestasis, minimal bile duct proliferation and fibrosis, and nearly complete absence of inflammation. In three patients in whom a portocholecystostomy was performed, no bile flow was obtained. Two patients underwent surgical exploration and liver biopsy only. One patient died as a result of severe congenital heart disease at 3 months of age. Four patients have undergone successful hepatic transplantation. These patients are now 10 months to 6 years of age. In our review of the literature, we were unable to find any reports of bile duct agenesis despite the fact that it appears to be a known phenomenon. We conclude that patients with biliary agenesis have early onset of jaundice when compared with patients with biliary atresia, absence of inflammation at the portahepatis at the time of surgical exploration, as well as on biopsy of the liver. Portoenterostomy or portocholecystostomy are likely to fail. We believe that liver transplantation is the treatment of choice for this rare entity.
From December 1986 to April 1989, 38 patients with biliary atresia (eight newly diagnosed) were evaluated with doppler ultrasound of the portal venous system. Peak and mean velocities were computer derived from the spectral waveform. Good velocity was greater than 15 cm/s, intermediate velocity was 8 to 14 cm/s, abnormal velocity was less than 7 cm/s or hepatofugal. Patients were grouped according to clinical status: group 1 (n = 14), normal liver function; group 2 (n = 15), recurrent cholangitis; group 3 (n = 2), established bile drainage but complicated cirrhosis; group 4 (n = 7), failed portoenterostomy. All patients with normal liver function (group 1) had good or intermediate velocities. Thirteen of 15 patients with recurrent cholangitis (group 2) had good or intermediate velocities. Both patients in this group with abnormal velocities required transplantation. In group 3 the patient with abnormal velocity is on the transplant waiting list. In group 4, abnormal velocities preceded or coincided with deterioration of liver function in five of seven patients. Doppler ultrasound provides useful anatomic information, determines direction of flow, quantitates velocity of flow, and, when performed serially, provides adjunctive information on liver status in children with biliary atresia. These preliminary results suggest that patients with abnormal or significantly decreasing velocity are destined for transplantation. Patients with good portal venous velocity warrant ongoing, aggressive surgical management.
Jaundice in the pediatric patient requires prompt and directed evaluation. This dictum is highlighted in infants with biliary atresia, in whom the progressive sclerosing process results in complete obliteration of patent but microscopic hilar biliary structures by 4 months of age. Kasai's operation, if done before that time, will re-establish bile drainage in 90% of infants. One fourth to one third of patients achieve long-term jaundice-free survival. Complications of cholangitis, portal hypertension, and fat malabsorption are experienced by many patients. In children with early or late operative failure, liver replacement now offers legitimate hope for extended survival. Choledochal cyst is a conglomerate of pancreaticobiliary anomalies consisting of a choledochal cyst, a common-channel-type pancreaticobiliary junction, intrahepatic cystic disease, and partial obstruction of the distal common bile duct. Many patients have one or more of these malformations. It is now widely accepted that the preferred treatment of choledochal cyst is total excision of the diseased biliary duct with reconstruction by Roux-en-Y choledochojejunostomy. "Internal" excision avoids injury to other structures in the hepatoduodenal ligament, particularly if pericystic inflammation is present. Congenital perforation of the common bile duct responds in most cases to simple peritoneal drainage of the perforation. Retention of the tube cholecystostomy is useful for subsequent cholangiographic follow-up. Tube cholecystostomy may also be useful for irrigation of the biliary tract in infants with inspissated bile syndrome.
Doses of 80, 160 and 320 mg of Inderal LA (slow-release propranolol) were compared in 12 patients with stable angina pectoris. There was an unpredictable and variable individual response to treatment and hence no differences were detected between the effects of the three doses on mean treadmill exercise duration, time to angina, frequency of angina or glyceryl/trinitrate consumption. There was a marked deterioration in two patients whilst on 320 mg Inderal LA. In these patients, the time to angina fell by 2 minutes 50 seconds and 4 minutes 20 seconds on 320 mg daily and 160 mg daily respectively. Given the inter-patient variability in response to Inderal LA, the dose for each patient should be individually titrated according to response. Two patients reported here suggest that some subjects may benefit from lower doses, although further work is required to clarify this point. Possible explanations for this finding are discussed.
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Analyses of bile bilirubin during the first month after Kasai operations, and of the liver biopsies obtained at the time of initial surgery, were done in 67 patients with biliary atresia. Bilirubin excretion (milligrams per day) was determined as the product of the bile volume and its concentration. Operative liver biopsies were evaluated for fibrosis, bile duct proliferation, bile stasis, giant cell transformation, and parenchymal degeneration; the severity of each abnormality was graded on a scale of 0 to 4. A forward stepwise regression procedure using the Cox proportional hazards model identified the relationship between survival and covariants. Thirty-nine of 67 patients died. Of these, 38 excreted less than 6 mg of bilirubin per day during the first postoperative month. The other patient died of a coexisting anomaly. Nine other patients who excreted less than 6 mg of bilirubin per day are alive but are either jaundiced or awaiting transplantation. Nineteen patients who excreted greater than or equal to 6 mg of bilirubin per day are alive (mean follow-up, 61 months) with normal or near-normal liver function. The severity of liver fibrosis, bile duct proliferation, and bile stasis did not correlate with survival, whereas giant cell transformation and parenchymal degeneration were highly significant (P less than or equal to .000 and P less than or equal to .0003, respectively). Twenty-six infants with grade 1-4 giant cell transformation or grade 2-4 parenchymal degeneration had a mean survival of 11 months.(ABSTRACT TRUNCATED AT 250 WORDS)