Biomedical subjects
Publications and source records attributed to M J Dalrymple-Hay.
Endoscopic harvesting of the long saphenous vein has been introduced to decrease the morbidity of obtaining venous conduit for coronary artery bypass grafting. Herein is described an endoscopic method using carbon dioxide insufflation into the tissues around the vein. This has several advantages; improved vision, no physical retraction required, easier development of tissue planes, and improved hemostasis.
BACKGROUND: The optimal management of critical aortic stenosis in early infancy remains controversial. The aim of this study was to assess the early and late outcomes following open surgical valvotomy for critical aortic stenosis in neonates and to provide a framework of data against which current results of other treatment approaches can be evaluated. METHODS: Eighteen consecutive neonates (mean age 9.2 days, range 1 to 26 days) undergoing an open valvotomy for critical isolated aortic stenosis (the standard treatment for this condition in our unit) between 1984 and 2000 were studied. The mean aortic valve gradient was 79.4 mm Hg. Twelve neonates received prostaglandins and 10 received inotropic agents preoperatively. Follow-up was complete (mean 8.1 years, range 1 month to 15 years). RESULTS: There was no operative mortality. At discharge, the mean aortic valve gradient was 37.2 mm Hg, with 6 patients having mild and 2 having moderate aortic regurgitation. Six patients required a reoperation; 3 of these had an aortic valve replacement at 9 to 11 years of age. Kaplan-Meier 5- and 10-year freedoms from any aortic reoperation or reintervention were 85 and 55%, respectively; 5- and 10-year freedoms from aortic valve replacement were 100 and 79%, respectively. A 14-year-old boy died from endocarditis 4 years following an aortic valve replacement in another unit. Kaplan-Meier 10-year survival was 100%. All survivors are in New York Heart Association I class and are leading normal lives. Their mean aortic valve gradient is 34.5 mm Hg, and none has significant aortic regurgitation. CONCLUSIONS: Open valvotomy for critical aortic stenosis in neonates carries a low operative risk and provides lengthy freedom from recurrent stenosis or regurgitation. Reoperations are inevitable, but aortic valve replacement can be delayed until the implantation of an adult-sized prosthesis is possible. Late survival is excellent. We consider open surgical valvotomy to be the treatment of choice for critical neonatal aortic stenosis.
INTRODUCTION: 10% of blood issued by the National Blood Service (220,000) is utilised in cardiac procedures. Transfusion reactions, infection risk and cost should stimulate us to decrease this transfusion rate. We tested the efficacy of autotransfusion of washed postoperative mediastinal fluid in a prospective randomized trial. PATIENTS AND METHODS: 166 patients undergoing coronary artery bypass grafting (CABG), valve or CABG + valve procedures were randomized into three groups. The indication for transfusion was a postoperative haemoglobin (Hb) < 10 g/l or a packed cell volume (PCV) < 30. When applicable, group A patients received washed post-operative drainage fluid. Group B all received blood processed from the cardiopulmonary bypass (CPB) circuit following separation from CPB and if appropriate washed post-operative drainage fluid. Group C were controls. Groups were compared using analysis of variance. RESULTS: There was no significant difference in age, sex, type of operation, CPB time and preoperative Hb and PCV between the groups. Blood requirements were as shown. [table - see text] Twelve patients in group A and 10 in group B did not require a homologous transfusion following processing of the mediastinal drainage fluid. CONCLUSION: Autotransfusion of washed postoperative mediastinal fluid can decrease the amount of homologous blood transfused following cardiac surgery. There was no demonstrable benefit in processing blood from the CPB circuit as well as mediastinal drainage fluid.
Increased thrombogenicity and acute embolism are well-recognized complications of chronic anabolic steroid abuse. The following cases highlight such dangers in steroid-enhanced bodybuilders who developed intracardiac thrombosis that subsequently embolized. Systemic anticoagulation and surgical thrombectomy constituted the mainstay treatment. This represents the first report of such devastating cardiovascular complications after anabolic steroid abuse and their management.
BACKGROUND: The CarboMedics bileaflet prosthetic heart valve was introduced in 1986. We first implanted it in March 1991. The purpose of this study was to analyze our clinical experience with this valve. METHODS: Between March 1991 and December 1997, 1,378 valves were implanted in 1,247 patients, 705 men (56.5%) and 542 (43.5%) women with a mean age of 62 +/- 11.9 years (+/- the standard deviation). Follow-up is 99% complete and totals 3,978 patient-years. RESULTS: The early mortality rate was 4.4% (55/1,247). The survival rates at 1 year and 5 years were 91.8% +/- 0.8% (+/- the standard error of mean) (n = 1,062) and 79.2% +/- 1.4% (n = 281), respectively. Freedom from valve-related complications (linearized rate, 4.9% per patient-year) at 1 year and 5 years was 90.6% +/- 0.8% (+/- the standard error of the mean) (n = 996) and 80.6% +/- 1.4% (n = 243), respectively. Linearized rates for various complications were as follows: bleeding events, 1.73% per patient-year; embolic events, 1.76% per patient-year; operated valvular endocarditis, 0.18% per patient-year; valve thrombosis, 0.10% per patient year; and nonstructural dysfunction, 1.21% per patient-year. Freedom from reoperation at 1 year and 5 years was 98.6% +/- 0.3% (+/- the standard error of the mean) (n = 1,070) and 97.7% +/- 0.5% (n = 285), respectively. CONCLUSIONS: Midterm results demonstrate that the CarboMedics prosthetic heart valve exhibits a low incidence of valve-related complications.
OBJECTIVE: The choice of the most appropriate substitute in children with irreparable aortic valve lesions remains controversial. The aim of this study was to assess early and late outcomes following aortic valve replacement (AVR) with mechanical prostheses in children. PATIENTS: Fifty-six patients (42 male, 14 female, mean age 11.2, range 1-16 years) undergoing AVR with mechanical prostheses between October 1972 and January 1999 were evaluated. Thirty-six patients (64.2%) underwent previous cardiac surgery. Disease aetiology was congenital in 47 patients (congenital aortic stenosis in 33, and other congenital abnormalities in 14) (83.9%), infective in four (7. 1%), rheumatic in two (3.4%), and three (5.3%) had connective tissue disorders. Haemodynamic indication for AVR was aortic regurgitation (AR) in 24 (42.8%), aortic stenosis (AS) in 22 (39.2%) and mixed disease in ten (17.8%). Twenty-eight patients (50.0%) were in New York Heart Association (NYHA) class III-IV before surgery. Concomitant procedures were performed in 31 patients (55.3%), including aortic root enlargement in 28 (50%). The mean size of implanted valves was 22.4 mm (range 17-27 mm). All patients received long-term anticoagulation treatment with sodium warfarin, aiming to maintain an international normalized ratio (INR) between 2.5-3.0. The mean follow-up was 7.3 years (range 0-26, total 405 patient-years). RESULTS: Operative mortality was 5.3% (three patients). Three patients developed complete heart block requiring pacing, two of them permanently. Late events included valve thrombosis (one), transient stroke (one), paravalvular leak of a mitral prosthesis (one), aneurysm of sinus of Valsalva (one) and pannus ingrowth (one). There was no major haemorrhagic event. Five patients required re-operation (8.9%), but none due to outgrowth of the valve. Regarding actuarial freedom from thrombo-embolism, any valve-related event and re-operation at 20 years was 93, 86.6 and 86. 4%. There were three late deaths. Actuarial survival, including operative mortality, at 10 and 20 years was 91 and 84.9%. The actuarial survival for the group of the patients with congenital AS (n=33) at 10 and 20 years was 93.5%, whereas for the children with other congenital heart problems (n=14) this was 85.7 and 64.3% (P=0. 09). At the latest clinical evaluation, 44 children were in NYHA class I and six were in class II. The mean gradient across the aortic prosthetic valve on echocardiography was 17.9 mmHg (range 0-47 mmHg). CONCLUSIONS: Mechanical AVR, with enlargement of the aortic root if necessary, remains an excellent treatment option in children. It is associated with acceptable operative mortality, low incidence of late events and re-operation, and provides good long-term survival. It clearly represents a good alternative to available biological substitutes, including the pulmonary autograft (Ross procedure).
BACKGROUND AND AIM OF THE STUDY: The CarboMedics bileaflet prosthetic heart valve was introduced in 1986, and first implanted by the authors in March 1991. The aim of this study was to analyze the authors' clinical experience with this valve. METHODS: Between March 1991 and October 1998, 1,503 valves were implanted in 1,350 patients (758 males, 592 female; mean age 62 +/- 13 years). Follow up was 99% complete and totaled 4,342 patient-years (pt-yr). RESULTS: The hospital mortality rate was 4.3% (59/1,350). Preoperative NYHA class (p = 0.012), emergency surgery (p = 0.03) and cardiopulmonary bypass time (p = 0.01) were significantly associated with increased risk of operative death (multiple logistic regression). Mean (+/- SEM) survival rates at one and five years were 92.0 +/- 0.7% (n = 1,109) and 80.0 +/- 1.3% (n = 335). Freedom from valve-related complications (linearized rate 5.6%/pt-yr) at one and five years was 89.5 +/- 0.8% (n = 1,031) and 76.3 +/- 1.4% (n = 284). Linearized rates for bleeding events were 2.19%/pt-yr, thromboembolic events 2%/pt-yr, operated valvular endocarditis 0.18%/pt-yr, valve thrombosis 0.14%/pt-yr and non-structural dysfunction 1.22%/pt-yr. Freedom from reoperation at one and five years was 98.5 +/- 0.3% (n = 1,107) and 97.3 +/- 0.5% (n = 334). CONCLUSION: Mid-term results demonstrate that the CarboMedics prosthetic heart valve exhibits a low incidence of valve-related complications.
BACKGROUND AND AIM OF THE STUDY: The study aim was to determine risk factors for operative mortality, recurrent infection, reoperation and long-term survival following aortic valve replacement (AVR) for infective endocarditis. METHODS: Between 1973 and 1997, 109 patients (91 male, 18 female, mean age 52.6 years) underwent isolated AVR for infective endocarditis in our unit. Native valve endocarditis was present in 89 (81.6%) and prosthetic valve endocarditis in 20 (18.4%). Active culture-positive endocarditis was present in 53 (48.6%). Preoperatively, 99 patients (90.8%) were in NYHA classes III and IV. Indications for surgery included cardiac failure in 41 patients, valvular dysfunction in 38, vegetations in 18, sepsis in seven, abscess in six and embolism in four. Mechanical valves were implanted in 69 patients (63.3%) and bioprostheses in 40 (36.7%), including a homograft in 19 (17.4%). Follow up was complete (mean 5.8 years; range: 0-23.8 years; total 633.5 patient-years). RESULTS: The operative mortality was 10.1% (11 deaths). At ten years, freedom from recurrent infection was 94.2%, and freedom from reoperation 83.6%. Biological valve and younger age were significant adverse parameters for freedom from reoperation (p = 0.01 and p = 0.01). There have been 21 late deaths, 15 due to cardiac causes. Kaplan-Meier survival, including operative mortality, at five and ten years was 77.4% and 68.0%, respectively. On Cox proportional hazards regression, Staphylococcus aureus infection (p = 0.008) and older age (p = 0.04) were independent adverse predictors of survival. CONCLUSION: AVR for endocarditis carries a relatively high operative mortality, but can result in a satisfactory freedom from recurrent infection, reoperation and long-term survival. Analysis of our series demonstrates that implantation of a biological valve limits the freedom from reoperation and that infection by Staph. aureus reduces the probability of long-term survival.
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OBJECTIVE: We report the combined early results from two centers in the United Kingdom using a composite conduit consisting of a bileaflet mechanical valve incorporated into a gelatin-impregnated, ultra-low porosity, woven polyester graft (Carbo-Seal; Sulzer Carbomedics, Inc, Austin, Tex). METHODS: Between August 1992 and March 1997, 143 patients underwent aortic root replacement with the Carbo-Seal composite prosthesis. The indication for surgery was acute type A dissection in 31 (22%), chronic type A dissection in 9 (6%), ascending aortic aneurysm without dissection in 100 (70%), and false aneurysm of the ascending aorta in 3 (2%). Twenty-seven patients (19%) had undergone previous sternotomy, and 40 (28%) were seen as emergencies. Concomitant procedures were performed in 38 (27%), including 18 aortic arch or hemiarch replacements. Total follow-up is 270 patient-years. Follow-up is 100% complete. RESULTS: The early (30-day) mortality was 7% (10 patients). Permanent neurologic events occurred in 2%. At a mean follow-up of 23 months, 94% of survivors were in New York Heart Association functional class I. Freedom from reoperation was 97.2% +/- 1.6% (1 standard error [1 SE]) at 12 months and 95.7% +/- 2.2% at 48 months. Including early mortality, survival was 90.1% +/- 2.6% at 12 months and 83.1% +/- 3. 5% at 48 months. CONCLUSIONS: Aortic root replacement with use of the Carbo-Seal prosthesis can be undertaken with a relatively low early mortality and morbidity. A low reoperation rate and high intermediate-term survival can be expected, but continued follow-up is needed to determine the long-term efficacy of this prosthesis.
OBJECTIVE: There has been a gradual increase in the number of elderly patients referred for cardiac surgery. These patients present a difficult challenge, they are usually symptomatic yet at high risk for intervention. The aim of this study is to review our experience with cardiac surgery in patients aged 80 years or older. PATIENTS AND METHODS: Between January 1981 and October 1997, 242 patients; 135 female, 107 male, mean age 82.8 years (range 80-95) underwent surgery on cardiopulmonary bypass in our unit. Surgery was performed on 14 as an emergency and 136 on an urgent (patient restricted to a hospital bed due to symptoms) basis. Pre-operatively 182 (75.2%) were in NYHA functional class 3 or 4. RESULTS: Early mortality was 14 (5.7%). A mitral valve procedure and emergency surgery were significantly associated (P < 0.05) with an increased risk of operative mortality. Median ITU and in-hospital stay was 1 day (range 0-33) and 10 (range 6-49) days, respectively. Ninety-three percent of patients were living independently at home 2 months post-operatively. Survival (+/-SEM) is 98% complete (totals 557 patient years) and including early mortality at 1 and 5 years was 85.5+/-2.4% (n = 154), and 67.7+/-4.3% (n = 33). Survival for patients undergoing isolated aortic valve replacement (AVR) and coronary artery bypass grafting (CABG) at 5 years was 64.8+/-7.8% and 79.7+/-7.4%, respectively. Survival was significantly worse in patients undergoing a mitral procedure. Using Cox's proportional hazards model only type of operation (mitral surgery) was significantly associated with worse survival. CONCLUSION: Cardiac surgery can be performed in a selected elderly population with a low operative mortality. Post-operatively elderly patients attain an excellent quality of life and survival. Emergency and mitral surgery in this group of patients is less rewarding.
OBJECTIVE: Following corrective cardiac surgery in infants and children for congenital heart disease, a persistent low cardiac output refractory to conventional modes of treatment is associated with a mortality approaching 100%. We advocate the use of whole body hypothermia to reduce tissue oxygen demand and provide a degree of cellular protection against ischaemia allowing time for recovery. We describe our experience. METHODS: Between July 1986 and December 1995, 1885 infants and children underwent surgery (operative mortality, 6%), 1302 requiring cardiopulmonary bypass. Fifty-seven patients had a persistent low cardiac output, impaired respiratory function, decreased urine output and acidosis despite maximal intensive care treatment. Cooling to 32-33 degrees C was therefore started using a thermostatically controlled water filled cooling blanket. RESULTS: Following cooling, there was a fall in heart rate (P<0.001), a rise in mean arterial pressure (P<0.001) and a fall in mean atrial pressure (P<0.001). Significant (P<0.001) increases in pH and urine output were also recorded. Thirty-one (54%) of the 57 patients treated with cooling survived to leave hospital. No long-term sequelae have been noted in these patients. CONCLUSION: Induced hypothermia is a useful salvage treatment, in children following corrective cardiac surgery when all conventional treatment has been tried and failed.
OBJECTIVE: Oesophageal carcinoma has a poor prognosis; surgical resection remains the only chance of cure but is still associated with a significant morbidity and mortality. The aim of this study was to review the results of one surgeon for oesophageal resection for carcinoma of the oesophagus and oesophagogastric junction over a 23 year period. METHODS: Between January 1974 and December 1996, 591 patients (408 males; 183 females; mean age 66 years) underwent an oesophageal resection for carcinoma of the oesophagus or oesophagogastric junction. RESULTS: In hospital mortality was 8.8% (52/591). This has decreased to less than 5% for resections between 1985 and 1996. Non-fatal complications occurred in 21% of patients (123/591). Survival, including in hospital mortality (+/-SEM), was 53.98% (+/-2), 31.77% (+/-2) and 15.3% (+/-2) at 1, 2 and 5 years respectively. CONCLUSION: Early mortality following oesophageal resection has fallen in recent years. Despite considerable experience, long term survival remains disappointingly low.
OBJECTIVES: The National Blood Service issues 2.2 million units of blood per year, 10% of these (220000) are utilized in cardiac procedures. Transfusion reactions, infection risk and cost should stimulate us to decrease this transfusion rate. We test the efficacy of autotransfusion following surgery in a prospective randomized trial. METHODS: One hundred and twelve patients undergoing CABG, valve or CABG + valve procedures were randomized into two groups. Group A received washed postoperative drainage fluid and group C were controls. The indication for transfusion was a postoperative haemoglobin (Hb) < 10 g/l or a PCV < 30. There was no significant difference in preoperative and operative variables between the groups. RESULTS: Twenty-eight patients in group A and 46 in group C required homologous transfusion (P = 0.0008). Group A patients required 298+/-49 ml of banked blood per patient, group C 508+/-49 ml (P = 0.003). There was no difference in total blood required (volume autotransfused + volume banked blood transfused) between the groups (group A 404+/-50 ml, group C 508+/-50 ml) or in mean total mediastinal fluid drainage (group A 652+/-51 ml, group C 686+/-50ml). The mean Hb concentration was significantly higher in group A on day 1 (11.2 g/dl+/-51 vs. 10.6 g/dl+/-13 (P = 0.002)). No morbidity was associated with autotransfusion. CONCLUSION: Autotransfusion can decrease the amount of homologous blood transfused following cardiac surgery. This represents a benefit to the patient and a decrease in cost to the health service.
OBJECTIVE: Between 1977 and 1988, 27 patients, mean age 8.9 (range 4-22) received an antibiotic sterilised aortic allograft in the setting of the Fontan procedure. This study describes the long-term follow-up of these patients. METHODS: Fifteen patients had tricuspid atresia, nine double inlet ventricles and three others. The connection with the allograft was made to the pulmonary artery on the right side of the aorta in ten and to a left-sided main pulmonary artery in eight. In nine patients the allograft was anastomosed between the right atrium and the right ventricle. RESULTS: There were five early and five late deaths. One late death may have been allograft related. Survival was 81, 74 and 68% at 5, 10 and 15 years, respectively. Conduit calcification was universal. Twelve patients underwent reoperation, freedom from reoperation was 100, 88 and 54% at 5, 10 and 15 years following the initial Fontan procedure. At reoperation the gradient across the allograft was never more than 3 mmHg. The allograft was explanted with conversion to atriopulmonary or cavopulmonary connection in nine and a second allograft was inserted between the right atrium and right ventricle in two. No mortality occurred at reoperation. 41.1% of survivors still have their original allograft. CONCLUSIONS: Although there is a significant attrition rate allograft inclusion in the Fontan circulation does not change survival, but results in an increased reoperation rate. Inclusion of a valved conduit between the right atrium and ventricle does not usually enhance the growth potential of the rudimentary ventricle. All patients are in a good functional class which may represent the strict original selection criteria. The inclusion of a valve in the Fontan circulation is not recommended.
BACKGROUND: A small proportion of cystic fibrosis patients develop severe localised bronchiectasis. When this persists despite maximal medical therapy it presents a difficult management problem. Lung transplantation cannot be justified. We report encouraging results in six patients with severe localised bronchiectasis and cystic fibrosis who underwent pulmonary resection. METHODS: Each child had severe localised bronchiectasis despite maximal medical therapy. Intensive preoperative toilet was instituted and pulmonary resection undertaken when lung function was optimal. RESULTS: There was a marked improvement in symptoms in every case. No significant long-standing morbidity was associated with the resection. There was no significant decrease in pulmonary function following resection. CONCLUSION: Pulmonary resection should be considered in the management of severe localised bronchiectasis unresponsive to maximal medical therapy in cystic fibrosis patients.
OBJECTIVE: There has been a gradual increase in the number of elderly patients referred for oesophageal surgery. The aim of this study is to review our experience with oesophageal cancer surgery in the elderly. METHODS: Between January 1974 and December 1996, 591 patients (408 males, 183 females; mean age 66 years) underwent an oesophageal resection for carcinoma. 221 were aged greater than 70 years of age (group A) and 370 less than 70 (group B). RESULTS: Total in hospital mortality was 8.8% (52/591). This has decreased to less than 5% over the last decade. There was no significant difference in perioperative morbidity or mortality between the groups (P = 0.11). When deaths from unrelated medical conditions were excluded, there was no significant difference in survival between the different age groups (P = 0.96). CONCLUSION: Oesophageal surgery can be performed in a selected elderly population with a low operative morbidity and mortality. The survival benefit of resection is the same in the elderly as for younger patients.