Biomedical subjects
Publications and source records attributed to D A Sharpe.
We describe our technique for excision of a renal tumor that extended to the right atrium and was adherent to the inferior vena cava within the liver. The surgical procedure was performed using cardiopulmonary bypass with deep hypothermic circulatory arrest and retrograde cerebral perfusion to extend the safe period of cerebral ischemia.
We report a case of chylopericardium and chylothorax after coronary artery bypass grafting, which presented as delayed cardiac tamponade. We describe the minimally invasive management of a condition that can be associated with a protracted surgical course.
Primary carcinomas of the lung and oesophagus are common, surgical resection offers the only hope of long-term survival with both conditions. We present the unusual case of a patient who underwent transhiatal oesophagectomy for an adenocarcinoma carcinoma of the oesophagus, 5 years after left pneumonectomy for small cell carcinoma of the lung.
Cardiopulmonary bypass (CPB) involves the use of either an occlusive roller pump or centrifugal pump. Damage to blood elements, including haemolysis, may arise from occlusion when using a roller pump; the appropriate degree of occlusion has not yet been determined scientifically. Centrifugal and nonocclusive roller pumps are reputed to reduce haemolysis. The objective of this study was to compare haemolysis caused by a standard roller pump with a dynamically set nonocclusive roller pump and with a centrifugal pump. We prospectively randomized 60 patients undergoing routine coronary artery surgery into three groups: standard roller pump (STD, n = 20), dynamically set roller pump (DYN, n = 20), or centrifugal pump (CEN, n = 20). The level of plasma free haemoglobin (FHb) was measured preoperatively, and the rate of formation of FHb (in mg/dl/min) was determined at the end of the ischaemic phase and at the end of CPB. Cardiotomy suction blood was isolated for the ischaemic phase and returned before the end of CPB. It was found that there were no differences between the groups in demographic or operative variables. The rate of formation of FHb at the end of the ischaemic phase was similar for all groups (STD 0.108 +/- 0.10, DYN 0.117 +/- 0.08, CEN 0.129 +/- 0.07). At the end of CPB, after return of the cardiotomy suction blood, there was a significant (< 0.001) increase in the rate of formation of FHb in all groups. The increase was similar for each of the groups (STD 0.424 +/- 0.17, DYN 0.481 +/- 0.20, CEN 0.471 +/- 0.18). We conclude that the rates of haemolysis are similar for each of the pump types, and no benefit is conferred by the use of either a dynamically set roller pump or a centrifugal pump compared with the standard roller pump. The return of the cardiotomy suction blood to the circulation is the principal source of plasma free haemoglobin.
Liver blood flow is reduced after cardiopulmonary bypass (CPB) and both dopamine and dopexamine are used to overcome this. This study compares the effects of these agents on liver blood flow. Thirty patients undergoing elective coronary artery bypass graft surgery were randomized into three groups (n = 10 per group). Six hours after surgery baseline liver blood flow was determined by the percentage disappearance rate of indocyanine green measured by dichromatic auricular densitometery. Patients then received infusions of either: (1) placebo (dextrose 5%); (2) dopamine (4 micrograms/kg/min); (3) dopexamine (1 microgram/kg/min increasing to 2 micrograms/kg/min). One hour after infusion, liver blood flow measurements were repeated. In the dopexamine group the infusion was increased and the measurements repeated another hour later. We found that patient-specific variables and operative details were similar for all groups. Postoperative cardiac index and heart rate were increased significantly by dopamine (cardiac index 2.82 +/- 0.46 l/m/m2 vs 3.28 +/- 0.67 l/m/m2: p < 0.001 and heart rate 87.5 +/- 13.2 vs 96 +/- 16: p < 0.05) and dopexamine at 2 micrograms/kg/min (cardiac index 2.71 +/- 0.53 l/m/m2 vs 3.45 +/- 0.67 l/m/m2: p < 0.05 and heart rate 89.0 +/- 18.9 vs 107.4 +/- 13.6: p < 0.001) compared to placebo (cardiac index 2.97 +/- 0.8 l/m/m2 vs 3.18 +/- 0.9 l/m/m2: p > 0.05 and heart rate 77.2 +/- 7.4 vs 77.3 +/- 8: p > 0.05) despite similar atrial and systemic arterial pressures. The disappearance rate of indocyanine green was not altered during infusion of placebo group (9.0 +/- 3.2%/min vs 7.9 +/- 3.0%/min: p > 0.05) or dopexamine at 1 microgram/kg/min (9.7 +/- 3.1%/min vs 11.2 +/- 4.1%/min: p > 0.05). The disappearance rate was increased with dopamine (6.7 +/- 3.7%/min vs 11.8 +/- 3.0%/min: p < 0.05) and dopexamine 2 micrograms/kg/min (9.7 +/- 3.1%/min vs 13.5 +/- 3.2%/min: p < 0.05). This indicates a 76% increase in liver blood flow with dopamine and a 38% increase with dopexamine. We conclude that dopamine 4 micrograms/kg/min and dopexamine 2 micrograms/kg/min increase liver blood flow, although this may, in part, be related to an increase in cardiac output. Dopexamine shows no advantage over dopamine in enhancing liver blood flow after CPB.
The minimally invasive limited lower sternotomy is a surgical approach for mitral valve operations with easy access to the left atrium. It confers the advantages of preservation of the sternocostal articulations and both internal thoracic arteries, with no need to enter either pleural cavity or resect the costal cartilages. It facilitates aortic and atrial cannulation for cardiopulmonary bypass, and allows easy access to the mitral valve through the left atrium.
The minimally invasive reversed Z sternotomy is a surgical approach for aortic valve operations that provides an excellent view of the aortic root and allows access to the right atrium. It confers the advantages of preservation of the sternocostal articulations and both internal thoracic arteries with no need to enter either pleural cavity. It facilitates aortic and atrial cannulation for cardiopulmonary bypass and allows access for a superior pulmonary vein cardiac vent.
OBJECTIVE: Our objectives were to determine factors which influence survival after resectional surgery in patients with cancer of the oesophagus and cardia. PATIENTS AND METHOD: 562 consecutive patients with primary cancer of the oesophagus or gastric cardia (oesophago-gastric junction) undergoing resectional surgery and reconstruction of the oesophagus were studied. Operative approach depended on tumour location, the aim being complete resection of the tumour and associated lymph nodes. Postoperative staging was based on tumour, nodes and metastasis (TNM) classification. RESULTS: There were 342 males and 220 females, aged 61.8 +/- 12.8 years. Histology of the tumours was: squamous cell carcinoma 49%, adenocarcinoma 47.5% and other tumours 3.5%. The location of tumours within the oesophagus was: cervical (n = 32), upper thoracic (n = 18), middle thoracic (n = 241) and lower thoracic and gastric cardia (n = 271). Of the tumours 16% were stage I, 10% stage II and 74% stage III. Hospital mortality rate was 9% overall, significantly higher in cervical tumours (cervical tumours versus lower and or middle oesophageal tumours: P < 0.05), the elderly (age > 75 years versus age < 75 years: P < 0.05) and stage III disease (stage III versus stage I: P < 0.001). The overall 5-year survival rate was 18%. There was no correlation between tumour histology, location or type of operation and long-term survival. Survival disease-free for 5 years or more was 73% for stage I, 15.8% for stage II and 6% for stage III. The only significant correlation was between the stage of disease and long-term survival (stage I versus stage III P < 0.001, stage I versus stage II P < 0.05). CONCLUSIONS: Immediate results are affected by a number of factors but long-term survival is related entirely to the stage of the tumour.
OBJECTIVE: To evaluate the efficacy of endoscopic laser treatment (ELT) in patients with endoluminal tracheal obstruction. METHOD: A neodymium: yttrium aluminium, garnet (Nd:YAG) laser was used on 60 patients with significant (> 50%) tracheal stenosis. They were grouped as follows: primary tracheal malignancy (PTM n = 11), secondary tracheal malignancy (STM n = 27), benign tracheal tumours (BTT n = 4) and inflammatory tracheal stenosis (ITS n = 18). Assessment was made clinically, endoscopically and using ventilatory function tests (forced vital capacity (FVC) and peak expiratory flow rate (PEFR)), before and after treatment. RESULTS: There was no treatment-related mortality. Peak expiratory flow rate improved significantly overall and in the PTM, STM and ITS groups. There was no significant improvement in FVC overall or in any of the individual groups. Subjectively, 98% of the patients felt improved by ELT. The survival in each group was: in the PTM group three patients are alive at 36, 49 and 74 months while all other patients died, giving a mean survival of 8.8 +/- 2.6 months. In the STM group the mean survival was 4.7 +/- 4.2 months. In the BTT group all patients are alive at the time of writing, two require regular ELT. In the ITS group three patients died, two required Montgomery tracheostomy tubes for tracheomalacia, seven are receiving regular ELT and six are disease free at the time of writing. CONCLUSION: We conclude that ELT is an effective method for the palliation of malignancy which occasionally gives long-term survival. It has a place in the management of benign tracheal neoplasia and inflammatory stenosis with a potential for cure in these cases.
OBJECTIVE: To assess early and long term (>5 years) results of tracheal resection and reconstruction. PATIENTS AND METHODS: Eighty-two patients amongst 144 with a variety of tracheal lesions, undergoing resection and reconstruction referred to a single surgeon. A retrospective study, the patients were grouped into: Group 1 neoplastic (n = 55) subdivided into: primary tracheal malignancy (PTM, 16), secondary tracheal malignant (STM, 38), benign tracheal neoplasia (BTN, 1); 21 patients in this group had tracheal patch grafts made of Marlex mesh and pericardium; six had a bifurcation resection. Group 2 consisted of non-neoplastic (27) sub-divided into: post-intubation injuries (PII, 24) and traumatic or congenital fistula of the trachea (CTL, 3); 23 patients in this group had circumferential, and the remaining four had partial circumferential, excision of the trachea followed by reconstruction. One patient in this group had tracheal patch graft. Hospital mortality/morbidity, relief of symptoms, recurrence of lesions and long-term survival are considered. RESULTS: Group 1: Five patients (9%) died in hospital; 12 patients, four (two with patch graft) in the PTM, seven (three with patch graft) in the STM group and one in the BTT group survived between 7 and 22 years, one patient is undergoing endoscopic laser. Group 2: There was one death 2 months after surgery. Two patients had recurrence of stricture, one requiring T tube stent, the other endoscopic laser therapy; 24 patients (one with patch graft) remain well between 7 and 22 years. CONCLUSION: Tracheal resection and reconstruction is attended by good functional results. The long-term outcome for malignant disease relates to the histology and tumour staging. Patch grafting using a composite prosthesis of Marlex mesh and pericardium has a chance of long-lasting success when used in selected patients.
We describe two cases of spontaneous haemopneumothorax treated successfully at emergency thoracotomy. We emphasize the importance of torn apical vascular adhesions as a source of intrathoracic haemorrhage in these two cases.
A neodymium:yttrium, aluminum, garnet (Nd:YAG) laser was used via the instrumentation port of a standard thoracoscope for the sealing of air leaks, ablation of bullae, transection of adhesions and partial parietal pleurectomy in 13 patients with intractable pneumothorax. The mean duration of tube thoracostomy prior to treatment was 10 days (range 4 to 21 days). All patients had intractable air leakage. Three patients had chronic lung collapse of over 50% despite adequate chest drainage. All cases were treated with thoracoscopic laser. The source of air leakage was found to be ruptured bullae in 11 cases and a lung tear in 2 cases. In five cases the bullae were multiple. In 11 cases the air leakage stopped within 24 h of treatment, with a single self-limiting episode of recurrent air leakage. In two of the cases of chronic pneumothorax the lung failed to expand because of sizable bronchopleural fistulae. They required thoracotomy stapling of bullae and limited thoracoplasty. The mean duration of tube thoracostomy after thoracoscopic laser in the 11 successfully treated patients was 2.72 days (range 1 to 5 days). We conclude laser-assisted thoracoscopy is a useful therapeutic option when treating persistent air leakage. In most cases this method prevents prolonged periods of tube thoracostomy and obviates thoracotomy. In cases of chronic collapse of the lung with bronchopleural fistulae this technique may not be successful.
A clinico-pathological study was carried out in two series of patients in order to determine: the prevalence of adenocarcinoma in Barrett's oesophagus in patients undergoing surgical resection for columnar cancer of the oesophagus, the incidence of Barrett's oesophagus in patients with complications of gastro-oesophageal reflux, and the subsequent cancer development in 3-20 years follow-up of such patients, compared with others who had no Barrett's oesophagus. Group 1 consisted of 264 patients with adenocarcinoma of the oesophagus undergoing resection and reconstruction; 18 (6.8%) had concomitant carcinoma and Barrett's oesophagus. These were predominantly male (male/female ratio 8/1) and had worse long-term survival than the other adenocarcinomas. Group 2 consisted of 782 patients with complications of gastro-oesophageal reflux, 26 (3.3%) of whom were found to have Barrett's oesophagus. When followed up for a period of up to 20 years, 4 (15.4%) of these developed cancer in the mean period of 11.5 years (1 case per 74 person-years). This is highly significant compared with 4 others (0.5%) who developed cancer amongst the 756 remaining patients in group 2 with no Barrett's oesophagus, in the mean interval of 8 years 2 months (1 case per over 1500 person-years). Of the 18 patients with Barrett's stricture, 4 (22%) developed cancer at a mean interval of 11.5 years representing one case per 51.7 person-years indicating a higher risk of cancer development in patients with Barrett's stricture compared with other patients with complications of gastro-oesophageal reflux with/without columnar epithelial-lined oesophagus and no stricture. Anti-reflux operation has not protected our patients with Barrett's oesophagus against cancer development.
We present a case of tracheoesophageal fistula that occurred after chemotherapy for stage IV B Hodgkin's lymphoma. We outline our surgical management of the case and advocate the use of a single-stage repair in selected cases.
A prospective randomised study to assess the efficacy of antibiotic prophylaxis in oesophageal surgery was performed, in which 226 consecutive patients (113 male and 113 female, age range 24-86 years, mean age of 65 years) were included. The study patients were in two groups: group 1, in which the upper alimentary tract was opened during surgery, and group 2, in which it was not. The group 1 patients (n = 129) were randomised to one of three antibiotic prophylaxis regimes prior to surgery. Group A patients (n = 42) were treated with cefuroxime (CFX) 1.5 g at induction of anaesthesia and then CFX 750 mg b.i.d. for 4 days. Group B patients (n = 46) were treated with CFX 1.5 g and metronidazole (MTR) 1.0 g at induction of anaesthesia, then CFX 750 mg b.i.d. and MTR 500 mg qds for 4 days. Group C (n = 41) treated with CFX 1.5 g and MTR 1.0 g at the induction of anaesthesia. Group 2 (n = 97) was divided into two groups, group D (n = 47) treated with CFX 1.5 g on induction of anaesthesia alone. Group E (n = 50) treated with CFX 1.5 g on induction of anaesthesia then CFX 750 mg bd for 2 days. We found a significantly higher incidence of infective complications in subgroup C (43.9%) and subgroup A (21.4%) compared to subgroup B (8.6%). This difference was most marked in patients undergoing oesophagectomy. We found significantly higher infection rates of infective complications in subgroup D (10.6%) as compared to subgroup E (2%).
A prospective study to investigate the source of pathogenic organisms responsible for infective complications of patients undergoing major oesophageal surgery was undertaken in 138 consecutive patients (38 female and 100 male) with obstructive lesions of the oesophagus, aged 24 to 86 years (mean 67 years). In all patients, the upper alimentary tract (UAT) was opened as part of the surgical procedure and 20.3% had pathogens present in their sputum before surgery. On direct culture of the contents of stomach or oesophagus at operation, 61% showed pathogenic organisms. Twenty-five patients suffered from 28 infections, predominantly pleuropulmonary infection (n = 19) but also wound sepsis (n = 8) and generalised infection (n = 1). Pathogenic organisms could not be cultured from the tracheobronchial tree immediately postoperatively. There was no correlation between preoperative sputum microbiology and postoperative infection. There was, however, a definite correlation (66% of cases) between pathogens of UAT content collected at operation and those responsible for postoperative infection. We conclude that it is relevant and important to regularly obtain samples of UAT content at operation to plan antibiotic regimes.
The requirement for hypothermia in myocardial protection has recently been questioned. Between October 1990 and May 1991, diastolic arrest was achieved using continuous perfusion with normothermic, hyperkalaemic blood in 257 consecutive patients undergoing cardiac surgery. The mean age was 59.8 +/- 9.3 years (range 28-84 years). Coronary artery surgery was performed in 210 patients, valve replacements in 18, combined procedures in 22, and 7 patients had miscellaneous procedures. Eleven patients (4.3%) had undergone previous cardiac surgery, and 65 (25.3%) required urgent or emergency operations. Hyperkalaemic blood (7-20 mmol/l) was delivered antegradely in 190 (72.8%) patients (mean aortic root pressure 60-80 mmHg), retrogradely in 62 (25.3%) patients (mean coronary sinus pressure less than 40 mmHg), and by a combined route in 5 (1.9%). Sinus rhythm returned immediately after removal of the aortic clamp in 235 (91.4%) patients. Weaning from bypass was achieved without circulatory support in 207 (82.5%) patients. Of 233 patients undergoing non-emergency coronary artery surgery, single valve or combined procedures, 11 died, giving an operative mortality of 4.7%. Of 155 patients with good left ventricular function requiring coronary artery surgery, 3 (1.9%) died. The in-hospital mortality for the group as a whole was 7.3%. Sixteen (6.2%) patients sustained perioperative myocardial infarctions; of these 6 died. We conclude that continuous, normothermic, hyperkalaemic arrest is a simple and safe method of myocardial protection. It may avoid the damage associated with hypothermia, ischaemia and reperfusion.
In a series of 560 pulmonary resections for bronchial carcinoma, unsuspected microscopic tumor was present at the bronchial resection margin in 26 patients (4.5%). Adjuvant chemotherapy or radiotherapy was given in two patients. In follow-up times ranging from 1 to 72 months (mean, 22 months), 58% of patients were alive and free of recurrent disease. Twelve patients underwent periodic surveillance bronchoscopy in an attempt to identify early local recurrence. Eighty-three percent of these patients were alive and disease-free in follow-up times from 4 to 72 months (mean, 29.7 months). Only one choscopies. It was concluded that microscopic residual resection-line tumor does not preclude prolonged survival and that no benefit from surveillance bronchoscopy could be demonstrated in this small patient sample.