Biomedical subjects

D G Pennington

Publications and source records attributed to D G Pennington.

At least 19 recordsLinked to original sources

PubMed1992

Microscopically controlled excision of skin cancer.

OBJECTIVE: To describe the technique of microscopically controlled excision of skin cancer (Moh's surgery) and to review the early experience of the use of this technique at Royal Prince Alfred Hospital. DESIGN: A review of 170 clinical records of patients with 198 skin malignancies treated by microscopically controlled excision from 1981 to 1983. PATIENTS: Long term follow-up of 148 patients with 170 lesions was possible. An analysis of these patients' sex and age, and the site, size and histopathological diagnosis of their lesions was carried out. INTERVENTIONS: All patients underwent microscopically controlled excision of their skin cancer. Analysis of the operative procedure revealed an average of 2.1 excision stages and 14.8 blocks examined by frozen section for each tumour. RESULTS: The overall cure rate was 97.1% for this group of patients. This rate is comparable with that of other centres performing this procedure. CONCLUSIONS: Microscopically controlled excision offers an excellent cure rate for skin cancers, especially recurrent, difficult basal cell carcinomas in areas known to be at high risk for recurrence, for example, central areas on the face. The application of this technique to selected patients and tumours offers a higher cure rate than conventional treatment methods.

Bowen's Disease↗

PubMed1992

Replacement of paracorporeal ventricular assist devices.

In this communication we describe a technique to change paracorporeal ventricular assist devices after the development of mechanical complications. This procedure is technically simple and in our experience does not require a sternotomy or cardiopulmonary bypass. Paracorporeal ventricular assist devices can be safely changed allowing continued support and survival.

Adult↗

PubMed1992

Effects of intraaortic balloon position on renal artery blood flow.

Debate continues over what happens to renal blood flow when intraaortic balloons are adjacent to the renal arteries. Fourteen dogs were prepared by implanting instruments to measure heart rate; right atrial, pulmonary arterial, carotid arterial, and femoral arterial pressures; cardiac index; mixed venous oxygen saturation; urine output; and left and right renal blood flows. A 12-mL intraaortic balloon was inserted through the left (n = 9) or right (n = 5) femoral artery. The position of the balloon was randomized so that it was initially placed in either the control (thoracic) or renal position (at the level of the renal arteries). Intraaortic balloon pumping was performed for 4 hours in each position. In 8 dogs, at least one of the renal arteries had partial occlusion, 23% to 98% decrease in flow (mean decrease, 66%), while the intraaortic balloon was in the renal position. An intraaortic balloon in the renal position results in lower renal blood flow as well as a high risk (57%) of selective renal artery occlusion. Decreased renal blood flow is not apparent using conventional monitoring, as hemodynamics do not change.

Animals↗

PubMed1992

Mitral valve replacement: randomized trial of St. Jude and Medtronic-Hall prostheses.

To better define the merits of the bileaflet and tilting-disc valves, we prospectively randomized 102 patients (mean age, 57 years; range, 11 to 85 years) to receive either the St. Jude (n = 55) or the Medtronic-Hall (n = 47) mitral valve prosthesis between September 1986 and May 1991. The two groups were not different with respect to preoperative New York Heart Association class, incidence of mitral stenosis and insufficiency, angina score, extent of coronary artery disease, ventricular function, completeness of revascularization, or cross-clamp or bypass time. The hospital mortality (14.5% versus 10.6%, St. Jude versus Medtronic-Hall) and late mortality (7.3% versus 2.1%) were not significantly different. Follow-up was complete in 84 of 89 hospital survivors (94%) with a mean of 26 months (range, 1 to 60 months). The linearized rates of valve-related events and the 3-year actuarial survival demonstrated no significant differences between both cohorts. Comparison of the clinical outcome and echocardiographic parameters obtained at the time of follow-up demonstrated no significant differences between the two prostheses. These data indicate that the Medtronic-Hall and St. Jude mitral prostheses are similar with respect to their rates of valve-related complications and hemodynamic profiles. This study suggests that there is no difference between the St. Jude and Medtronic-Hall prostheses with regard to early clinical performance or hemodynamic results and therefore does not support the preferential selection of either prosthesis.

Adolescent↗

PubMed1992

Prolonged extracorporeal support for nonneonatal respiratory failure.

Extracorporeal membrane oxygenation (ECMO) is effective for newborns with pulmonary failure unresponsive to conventional therapy. However, ECMO for the older child and adult has been controversial and not widely utilized. Over 4 years, 24 patients (aged 4 months to 16 years; 11 boys, 13 girls) underwent venoarterial ECMO (duration, 7 to 19 days) for respiratory failure. The diagnoses were: viral pneumonia (7), hydrocarbon aspiration (6), sepsis with adult respiratory distress syndrome (ARDS) (2), bacterial pneumonitis (2), tracheal stenosis (1), bilateral pulmonary contusion (1), diaphragmatic hernia with ARDS (1), ketoacidosis with ARDS (1), pulmonary artery injection of hydrocarbon (1), drowning (1), and epiglottis with barotrauma (1). Pre-ECMO blood gas ranges (and means) were PO2 18 to 65 (46), and PCO2 47 to 112 (65). Nineteen patients received dopamine, dobutamine, or other inotrope for associated cardiac and/or renal failure. Cannulation for ECMO was through neck or groin vessels in 17, and sternotomy in 7. ECMO flow rates were 150 to 250 mL/kg/min, to maintain PO2 greater than 100 and PCO2 less than 40. Nine patients (41%) survived ECMO, with eight long-term survivors, (4 hydrocarbon aspiration or injection, 1 pulmonary contusion, 1 viral pneumonia, 1 ARDS, 1 barotrauma), three of whom have mild neurological deficit. All patients with sternotomy, and 8 of 15 with neck and/or groin cannulation, required 1 to 5 explorations for hemorrhage while on ECMO. All survivors had primarily pulmonary failure; patients with combinations of pulmonary, cardiac, and renal failure did not survive. ECMO can be life-saving in the child with isolated pulmonary failure, but its efficacy in patients with multiorgan failure is uncertain.

Adolescent↗

PubMed1992

Conservative versus surgical management of chylothorax.

Chylothorax is a potentially life-threatening disorder that has profound respiratory, nutritional, and immunologic consequences. Treatment for this problem is controversial, and the results have been variable. From 1985 to 1990, 29 patients (16 males, 13 females; mean age: 20.1 years; range: 5 days to 76.8 years) were diagnosed as having chylothorax (18 right, 6 left, 5 bilateral). Etiologies included surgical trauma (26) and nonsurgical trauma (3). Initial conservative treatment consisted of tube thoracostomy drainage (mean duration: 13.3 days; range: 1 to 62 days; mean total volume: 4,030 mL) and dietary modification (low-fat diet, total parenteral nutrition). This resulted in resolution of the chylothorax in 23 patients (79% success), although 2 patients died of unrelated causes while hospitalized (myocardial infarction and cardiopulmonary arrest). Five adult patients and one infant (21%) required ligation of the thoracic duct, with resolution of the chylothorax in all six (100% success). Despite successful duct closure, one infant died of respiratory failure unrelated to the operation, and one adult died as the result of a cerebrovascular accident 6 weeks postoperatively, yielding an operative mortality of 33% and an overall mortality of 14% (4 of 29). Our experience demonstrates that initial treatment of chylothorax with thoracostomy drainage and dietary modification is successful in the majority of patients and is not associated with high morbidity or mortality rates. Surgical intervention for chylothoraces that fail to respond to initial conservative measures will be required in a minority of patients but appears to be associated with a higher risk of complications.

Adolescent↗

PubMed1992

Hemangiopericytoma of the hand: a literature review and case study.

We present a case of hemangiopericytoma of the hand. We also attempt to differentiate hemangiopericytoma from glomus tumor with a summary of the history and a comprehensive review of the literature demonstrating the malignant character of the neoplasm, and we offer some guidelines for treatment.

Angiography, Digital Subtraction↗

PubMed1992

Extracorporeal membrane oxygenation in children after cardiac surgery.

BACKGROUND: From August 1982 to May 1991, 65 children (32 boys), 1 day to 14 years old, received extracorporeal membrane oxygenation (ECMO) 0-50 hours after cardiac surgery. Forty-four (67.7%) were weaned, with 23 (35.4%) survivors. METHODS AND RESULTS: Analysis of 29 pre-ECMO factors including diagnosis, age, sex, blood gas data, systemic pressures, atrial pressures, ventricular function, and renal function was performed. Preoperative systemic ventricular shortening fraction was statistically less in survivors. The need for dialysis and length of support were predictors of survival once ECMO was initiated. There were five late deaths 6 days to 5 years after discharge; none were related to ECMO. The remaining 18 patients have been followed for a mean of 37.5 months (range, 1-85 months). Seventeen are New York Heart Association functional class I, with one patient still hospitalized. CONCLUSIONS: ECMO allows for myocardial recovery in the majority of patients with refractory postcardiotomy failure and permits some patients to survive who would not have otherwise.

Adolescent↗

PubMed1992

Intraaortic balloon pumping in patients requiring cardiac operations. Risk analysis and long-term follow-up.

The intraaortic balloon pump is usually the first mechanical device inserted for perioperative cardiac failure; however, little current information is available regarding short- and long-term effectiveness. From January 1983 through November 1990, 6856 adult patients underwent cardiac surgical procedures, 580 of whom (8.5%) had an intraaortic balloon inserted preoperatively (107 patients), intraoperatively (419 patients), or postoperatively (54 patients). There were 374 men and 206 women with a mean age of 63.9 years (range 19 to 88). Operations included 376 coronary artery bypass grafts, 100 mitral valve replacements (with or without bypass grafting), 70 aortic valve replacements (with or without bypass grafting), 15 double valve replacements (with or without bypass grafting), and 32 other procedures. There were 72 (12.4%) complications related to the balloon pump, of which 42 necessitated surgical intervention including thrombectomy (21), vascular repair (13), fasciotomy (2), aortic repair (1), and amputation (4). Operative mortality for patients supported by the balloon pump was 44%. Multivariate stepwise analysis of 27 parameters revealed six independent predictors of mortality: preoperative New York Heart Association class, transthoracic intraaortic balloon insertion (both p < 0.0001), preoperative administration of intravenous nitroglycerin, age, female gender, and preoperative balloon insertion (p < 0.001). Balloon-related complications were not predictive of death. Of the 326 hospital survivors, only 34 were lost to follow-up. There were 75 late deaths, the cause of which was cardiac in 41 (55%), noncardiac in 20 (27%), and unknown in 14 (19%). Actuarial survivals at 1, 5, and 9 years are 51%, 42%, and 33%. Of the 217 hospital survivors still alive and contacted, 81% were in class I (114) or II (60). These data demonstrate (1) operative mortality for patients requiring an intraaortic balloon in the perioperative period remains high, (2) perioperative risk factors can be identified, (3) complications related to the balloon pump do not affect survival, (4) operative survivors can achieve prolonged survival with excellent functional results, and (5) consideration for alternative methods of circulatory support is justified.

Actuarial Analysis↗

PubMed1992

Aortic valve replacement. Aortic root versus coronary sinus perfusion with blood cardioplegic solution.

The role of retrograde coronary sinus cardioplegia in patients undergoing aortic valve replacement for aortic stenosis alone or in combination with myocardial revascularization has not been fully defined. Sixty-three patients undergoing elective aortic valve replacement received cold potassium blood cardioplegic solution via either the aortic root (36 patients) or the coronary sinus (27 patients). The patients were similar with respect to age, degree of aortic stenosis, ventricular function, severity of coronary artery disease, crossclamp time, completeness of revascularization, and mean volume and temperature of the infusion solution. The mean septal temperature and the release of myocardium-specific isoenzyme in the first 2 hours after crossclamp removal was higher in the retrograde group (p less than 0.008). Right and left ventricular function was preserved equally in the two groups, and volume-loading studies suggested improved diastolic performance in patients having retrograde cardioplegia. There were no differences between the two groups with respect to clinical outcome. We conclude that coronary sinus cardioplegia is as safe as aortic root perfusion for myocardial preservation in patients undergoing elective aortic valve replacement.

Aorta↗

PubMed1991

Pediatric cardiac rehabilitation.

Sixteen patients participated in a Pediatric/Young Adult Cardiac Rehabilitation Program that included exercise training, education about cardiovascular diseases, dietary counseling, and counseling on stress management. Seven patients completed the program, and complete data were available on six. The subjects demonstrated significant changes in their hemodynamics and exercise tolerance after completing the program. Resting blood pressure decreased by 7%, from 119 +/- 12 to 111 +/- 10 mm Hg; peak oxygen consumption increased by 20%, from 31.9 +/- 4.3 mL/kg of body weight per minute to 38.4 +/- 6.0 mL/kg of body weight per minute; and exercise treadmill time increased by 21%, from 8.5 +/- 1.4 to 10.3 +/- 1.0 minutes. No complications occurred during exercise training or testing. Supervised exercise training at moderate intensity is safe and produces significant and beneficial changes in hemodynamics and exercise time in children with cardiac disease.

Adolescent↗

PubMed1991

Reliability of echocardiography in the diagnosis of anomalous origin of the left coronary artery from the pulmonary trunk.

Previous studies have indicated that the definitive diagnosis of anomalous origin of the left coronary artery from the pulmonary trunk (ALC) should be made by cardiac catheterization and angiography. This study evaluates echocardiography (two-dimensional, pulsed Doppler, and color flow mapping) as a method to establish the diagnosis of ALC. To diagnose ALC, a modified parasternal short-axis view was used to demonstrate continuity of the ALC with the pulmonary trunk and to detect the retrograde flow through the ALC into the pulmonary trunk. Absence of these imaging characteristics ruled out ALC. From June 1985 to January 1990, 16 patients who presented with or had previously had a dilated poorly contracting left ventricle were prospectively assessed by echocardiography to rule out ALC. Four patients had ALC (age 2 to 120 months, mean +/- 1SD = 32 +/- 59) and 12 patients (age 1 to 192 months, mean +/- 1SD = 57 +/- 80) had myocardiopathy. Two other patients with known ALC were evaluated by an observer unaware of the diagnosis. All coronary anatomy was confirmed by angiography, surgery, or autopsy. The correct diagnosis of coronary anatomy was obtained by echocardiography in all instances without false positive or false negative diagnosis of ALC. Three infants underwent surgical repair of ALC based only on the echocardiographic diagnosis. Echocardiography can be used to establish the diagnosis of ALC. Therefore surgical repair can be undertaken in some critically sick infants based on the echocardiographic diagnosis alone.

Cardiac Catheterization↗

PubMed1991

Heart transplantation in children: an international survey.

A survey of cardiac transplantation in children provided data from 381 transplantations in 362 patients from 32 centers in the United States and ten international centers. The number of transplantations continues to increase, in part because of transplantations in infants with hypoplastic left heart syndrome and patients with congenital defects. The immunosuppression regimens were more uniform than in the 1985 survey, and triple therapy was most common. Actuarial survival rates were 85% at 1 month, 72% at 1 year, 64% at 3 years, and 60% at 5 years. However, these improved rates are still not equal to the survival of the overall cardiac transplant population, in part because of lower survival rates in neonates. Ventricular dysfunction and rejection, rather than infection, were the leading causes of death. Rejection and infection were the most frequent complications. Also common were hypertension (39%) and seizures (25%), whereas coronary artery disease (8%) was unusual. Functional results were excellent in 85%, and only 7% were disabled. Questions concerning growth rates and many other aspects cannot yet be answered. However, it is apparent that cardiac transplantation in the pediatric population is a very worthwhile endeavor.

Actuarial Analysis↗

PubMed1991

Pericardial drainage: subxiphoid vs. transthoracic approach.

The optimal management of effusive pericardial disease remains controversial. Subxiphoid drainage has been criticized for a high recurrence rate while transthoracic procedures (window or pericardiectomy) are more invasive operations with greater potential for morbidity. We compared subxiphoid (SX group) and transthoracic (TT group) drainage in 131 patients (age range from 1 month to 81 years) treated from 1979 to the present. The etiology of effusion included cancer (38), uremia (24), infection (27), radiation (9), and other (33) causes. The two groups had similar age and sex distribution, etiology, and fluid volume. There was no difference in the operative mortality between the two groups (SX 15%, TT 13%, p = NS). Patients undergoing thoracotomy for treatment of effusive pericardial disease had a higher incidence of respiratory complications as defined by the presence of pneumonia, pleural effusion, prolonged ventilation, and need for reintubation (SX 11%, TT 35%, p less than 0.005). This may account, in part, for the longer mean hospital stay in transthoracic group (14.4 vs. 11.4 days). Nine patients were lost to follow-up after hospital discharge. The remaining 104 hospital survivors were followed for between 1 month and 11 years (mean 34 months, cumulative of 297 patient years). Three patients in each group experienced fluid recurrence and all but one were successfully treated by needle aspiration or percutaneous catheter placement. Following discharge, no patient required reoperation for effusive or constrictive pericardial disease or died from tamponade. There were no significant differences in 5-year actuarial survival (SX 54%, TT 49%) or actuarial freedom from recurrence (SX 89%, TT 93%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1991

Fifteen-year follow-up for double internal thoracic artery grafts.

The internal mammary artery (IMA) is the conduit of choice for myocardial revascularization. From 1972 to 1989, 586 patients received bilateral IMA and supplemental vein grafts. There were 506 men (86%) and 79 women (14%) with a mean age of 55.5 years (range 32-77 years). Unstable angina was present in 138 patients (24%), insulin-requiring diabetes mellitus in 83 (14%) and previous myocardial infarction (MI) in 25 (4%). Preoperative angiography demonstrated triple-vessel disease in 286 patients (49%) and double-vessel disease in the remaining 300 patients (51%). Left main coronary artery disease (stenosis greater than or equal to 50%) was present in 53 (9%). The mean left ventricular score was 7.4 with a range of 5 to 20. The mean number of grafts performed was 3.4 per patient. Hospital mortality was 3.6% (21 patients). Follow-up was done through direct patient contact, via the patient's physician or by telephone contact with the patient themselves or surviving family members. Follow-up was complete in 518 hospital survivors and ranged from 1 month to 17.5 years with a cumulative follow-up of 911 patient years. At 10 and 15 years, respectively, the actuarial freedom from MI was 78% and 72% and freedom from reoperation was 93% and 86%. Actuarial survival at 10 and 15 years was 85% and 70%, respectively. This longitudinal analysis demonstrates that bilateral IMA grafting has a low operative risk. The data suggest that utilization of two IMA grafts yield excellent freedom from recurrent symptoms and provides excellent long-term survival.

Actuarial Analysis↗

PubMed1991

Fibrosarcoma of metacarpal treated by combined therapy and immediate reconstruction with vascularized bone graft.

Fibrosarcomas of the bones of the hand are very rare entities. We present a case of low-grade fibrosarcoma of the left third metacarpal that was successfully treated by preoperative intraarterial chemotherapy, wide local excision, and immediate reconstruction with a vascularized bone graft from the ipsilateral radius. Excellent hand function has been preserved and the patient remains free of recurrence 5 years after presentation.

Adolescent↗

PubMed1991

The free transverse rectus abdominis myocutaneous flap in breast reconstruction after mastectomy.

Breast reconstruction after mastectomy by the transverse rectus abdominis myocutaneous (TRAM) flap technique is a widely accepted method which allows reconstruction without the need for an implanted silicone prosthesis. Even in suitable patients, deficiencies of the traditional technique, where the blood supply is based on anastomotic vessels in the superior part of the rectus abdominis muscle, may lead to complications. These include flap failure, fat necrosis which may mimic recurrence of breast carcinoma or sub-optimal cosmetic results. By transferring the same abdominal tissue as a free flap based on the inferior epigastric vessels, a more reliable blood supply and better cosmetic results can be obtained. This article reports a series of 14 flaps in 13 patients in whom an entirely free flap technique was used. No flap losses were recorded and the results are judged to be superior to the traditional technique.

Abdominal Muscles↗

PubMed1991

Surveillance for rejection by echocardiographically guided endomyocardial biopsy in the infant heart transplant recipient.

Echocardiographically guided endomyocardial biopsy via percutaneous right internal jugular vein puncture has been performed 98 times in six patients 5-16 years of age at our institutions. The use of this approach was extended for rejection surveillance in seven infants transplanted at 2 weeks to 15 months of age (median, 2 months; mode, 2 weeks). A total of 35 consecutive biopsies were performed under heavy sedation in these infants (lowest weight, 3.0 kg) with the use of a 5F semirigid bioptome through a 5.0-cm 5F sheath. There was no case of entrance failure. A median of four biopsies was performed on each child (range, one to 14). Four to seven tissue pieces per biopsy were obtained using an apical four-chamber view for bioptome guidance. Ten instances of clinically suspected rejection were not confirmed by biopsy, and two cases of unsuspected rejection were found. The only complication was one instance of new mild tricuspid regurgitation in this group compared with one instance of increased tricuspid regurgitation after biopsy in the older child group. These preliminary results suggest that echocardiographically guided endomyocardial biopsy from the right internal jugular approach is a reliable and safe means for rejection surveillance in the infant and young child.

Biopsy↗