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Dive into the research topics where William S. Walker is active.

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Featured researches published by William S. Walker.


European Journal of Cardio-Thoracic Surgery | 1991

Influence of obesity on the early and long term results of surgery for coronary artery disease.

U. S. Prasad; William S. Walker; C. T. M. Sang; C. Campanella; Evan W.J. Cameron

In order to determine the effect of obesity on the results of coronary artery bypass graft (CABG) surgery, we compared 250 obese patients undergoing CABG procedures between 1984 and 1987 with 250 age- and sex-matched controls of normal body mass index (BMI) undergoing CABG in the same period. The obese group had a greater incidence of diabetes mellitus (p less than 0.02), hypertension (p less than 0.05), hyperlipidaemia (p less than 0.05), and left main stem coronary artery disease (p less than 0.001). No differences were identified in the surgery performed, but obesity was associated with prolonged total bypass time (p less than 0.05). Operative mortality was 0.8% in both groups. Multivariate analysis demonstrated obesity to be an independent risk factor for perioperative morbidity (p less than 0.05). Univariate: respiratory (p less than 0.01); leg wound (p less than 0.001); myocardial infarction (p less than 0.02); arrhythmias (p less than 0.02); sternal dehiscence (p less than 0.02). At a mean follow-up time of 36.9 months obese patients exhibited a greater incidence of significant recurrent angina (p less than 0.01), which was associated with further weight gain (mean 12.2 kg; linear correlation: p less than 0.001, r = 0.891). Although in CABG surgery operative mortality is not increased in obese patients, aggressive pre- and postoperative weight control is indicated to reduce both perioperative morbidity and the incidence of recurrent angina.


Thorax | 1994

Efficacy of video assisted thoracoscopic lung biopsy: an historical comparison with open lung biopsy.

F. M. Carnochan; William S. Walker; E. W. J. Cameron

BACKGROUND--Video assisted thoracoscopic lung biopsies were compared with historical controls undergoing open lung biopsy to determine the diagnostic accuracy, effect on length of postoperative stay, and cost effectiveness of the new thoracoscopic technique. METHODS--The first 25 video assisted thoracoscopic lung biopsies performed in the Edinburgh Thoracic Unit were compared with 25 historical controls for complications, diagnostic accuracy, and length of postoperative stay. RESULTS--Statistical comparison showed equal diagnostic accuracy in both groups (96% v 92%), but mean (SD) inpatient stay was reduced in the video assisted thoracoscopic group (1.4 (0.7) days) compared with those undergoing open lung biopsy (3.1 (1.8) days). No postoperative complications were reported in the group which underwent video assisted thoracoscopic lung biopsies but three patients had postoperative complications in the open lung biopsy group. CONCLUSIONS--Video assisted thoracoscopic lung biopsy is as effective in providing histological diagnosis as is open lung biopsy. All postoperative complications were related to post thoracotomy pain and occurred only in patients undergoing open lung biopsy. Reduced postoperative disability in the video assisted thoracoscopic group decreased hospital stay, offsetting the increased cost in disposables. The overall cost of video assisted thoracoscopic and open lung biopsy was 712 pounds and 1114 pounds, respectively.


European Journal of Cardio-Thoracic Surgery | 2003

Immediate and long-term results of mitral prosthetic replacement using a right thoracotomy beating heart technique

M.J. Thompson; A. Behranwala; C. Campanella; William S. Walker; Evan W.J. Cameron

OBJECTIVE Repeat median sternotomy is a potentially dangerous technique providing variable but mainly poor access to the mitral valve. Right thoracotomy is an alternative route previously used to access the mitral valve in the early years of cardiac surgery that offers the advantage of a fresh surgical field in the context of redo surgery. We have reviewed our experience with mitral prosthetic replacement undertaken via a right thoracotomy in order to determine the immediate and long-term results obtained with this approach. METHODS The operation was carried out on a beating heart using normothermic bypass without cross-clamping the aorta. Arterial inflow was achieved via the femoral artery or ascending aorta and venous drainage with bi-caval cannulae. Pre-, intra- and postoperative data were documented from case note review. Long-term follow-up was established from the UK Heart Valve Registry, referring Cardiologist, direct patient contact and the Scottish Registry for births and deaths. Statistical analysis was undertaken using a desktop computer package. RESULTS One hundred and twenty-five patients (mean age 63 years) underwent mitral prosthetic replacement by this technique. One hundred and eleven patients (86%) were in NYHA grades III or IV preoperatively. Twenty-two patients (16.6%) had also undergone previous CABG. Thirty-five patients (28%) had undergone two or more sternotomies. Mean bypass time was 83.6 min (SD 43.1). Postoperatively, mean duration of ventilation was 44 h; mean ITU stay was 4 days (SD 5.3) and mean inpatient total stay was 12 days. Thirty-six patients (28.8%) required inotropic support postoperatively. Complication rates were low: pleuro-pulmonary, 30 patients (24%), re-operation for bleeding, four patients (3.2%) and CVA, two patients (1.6%). Eight patients (6.4%) died within 30 days. Ten-year survival figures (Kaplan-Meier) were: 47% for all causes of mortality and 82.9% when only valve related causes of death were considered. Most of the patients (97.5%) had not required re-operation at 10 years. CONCLUSION Mitral prosthetic replacement via a right thoracotomy on beating heart under normothermic bypass offers a safe alternative to redo median sternotomy in this high-risk group. Operative access is facilitated and procedural time reduced. Complication rates are low and perioperative mortality is lower than that generally reported with conventional surgery.


Thorax | 1993

Synchronous primary lung cancers: prevalence in surgical material and clinical implications.

F A Carey; Seamas C. Donnelly; William S. Walker; Evan W.J. Cameron; D. Lamb

BACKGROUND--The prevalence of synchronous primary lung neoplasms in surgical resection specimens was assessed. The associated clinical features and prognostic implications were investigated. METHODS--All surgical resections for lung cancer performed during seven years were reviewed. Synchronous tumours were defined by the presence of more than one tumour mass in the lung, by differences in histological subtype, by the presence of separate bronchial origins, or by differences in DNA stemlines. Clinical data were abstracted from case notes and information from the tumour registry. RESULTS--Just under 2% of all surgical specimens in the study period contained more than one primary carcinoma. The patients did not differ clinically from the general population of patients having surgery for lung cancer. The overall prognosis was poor (mean survival 27 months) but was significantly better for patients with synchronous squamous carcinomas (mean survival 49 months). CONCLUSION--Synchronous primary lung carcinomas are associated with a poor prognosis except in patients having tumours only of squamous histological type.


Thorax | 1989

Long term survival after pulmonary resection for small cell carcinoma of the lung.

U. S. Prasad; A. R. Naylor; William S. Walker; D. Lamb; Evan W.J. Cameron; P. R. Walbaum

A retrospective review was undertaken of the long term survival of 97 patients with histologically proved small cell carcinoma of the lung resected during the 10 years January 1977-December 1986. Twenty seven patients (28%) had stage I disease, 29 (30%) stage II, and 41 (42%) stage III. Patients with stage I and II tumours were managed by resection alone. Patients with stage III disease received adjuvant chemotherapy (cyclophosphamide, doxorubicin, and vincristine). Pneumonectomy was undertaken in 75 patients, lobectomy in 21, and wedge resection in one patient. Three patients died within 30 days of operation. The cumulative five year survival of all patients, irrespective of tumour stage, was 17%. The cumulative five year survival was 35% for patients with stage I disease, 23% for stage II, and zero for stage III. The median survival for patients with stage III tumours was 17 months. There was no significant difference in cumulative survival between patients with stage I and II disease. Cumulative survival, however, was significantly better for patients with stage I and II disease than for those with stage III disease. The data suggest that for patients with stage I and stage II disease surgery offers the prospect of long term survival.


The Annals of Thoracic Surgery | 1989

Comparison of Ventricular Septal Surgery and Mitral Valve Replacement for Hypertrophic Obstructive Cardiomyopathy

William S. Walker; K.G. Reid; Evan W.J. Cameron; P.R. Walbaum; A.H. Kitchin

We have reviewed the results of two different forms of surgical management of hypertrophic obstructive cardiomyopathy refractory to medical therapy. Twenty-one patients were treated with 22 procedures between 1963 and 1987. Eleven underwent a ventricular septal procedure by myotomy with or without myectomy, and 11 underwent mitral valve replacement (MVR), 1 of whom had previously undergone a ventricular septal procedure. The groups were comparable with respect to severity and duration of symptoms, age range, electrocardiographic features, and hemodynamic changes. Mitral valve replacement produced a greater and more consistent reduction in the left ventricular outflow tract pressure gradient than a ventricular septal procedure (MVR, 68.3 mm Hg preoperatively and 2.5 mm Hg postoperatively; ventricular septal procedure, 60.1 mm Hg preoperatively and 13.4 mm Hg postoperatively). This was associated with better postoperative ventricular configuration in diastole and more apparent loss of midcavity narrowing in systole. Ejection fraction did not fall after a ventricular septal procedure but decreased significantly from a mean of 79% to a mean of 61% after MVR. Similarly, left ventricular end-diastolic pressure remained unchanged after a ventricular septal procedure but fell from a mean of 26.6 mm Hg to 17 mm Hg after MVR. Although both groups experienced a generally satisfactory symptomatic result, this appeared more reliable with MVR. We suggest that MVR offers a more predictable improvement than a ventricular septal procedure and may be the procedure of choice for units with limited experience with ventricular septal procedures.


Critical Care Medicine | 2000

Pulmonary endothelial permeability and circulating neutrophil-endothelial markers in patients undergoing esophagogastrectomy.

Peter T. Reid; Seamas C. Donnelly; Ian R. Macgregor; I. S. Grant; Evan W.J. Cameron; William S. Walker; Malcolm V. Merrick; Christopher Haslett

ObjectiveEsophagogastrectomy is an established surgical treatment for esophageal malignancy. The postoperative period may be complicated by the development of acute lung injury syndromes and thus, may provide a useful model in which to study the early pathogenic mechanisms of inflammatory lung injury. DesignOpen, prospective study. SettingHigh dependency and intensive therapy units. PatientsEight healthy male volunteers and 20 patients in the early postoperative period InterventionsNone. Measurements and Main ResultsThe lung protein accumulation index (PAI) of radiolabeled transferrin was determined by using a portable, double-isotope system. The following circulating inflammatory markers–thought to reflect neutrophil-endothelial activation and injury including circulating neutrophil elastase–soluble L-, E-, and P-selectins and thrombomodulin and von Willebrand factor antigen were assayed from venous blood samples The PAI for healthy volunteers was median −0.5 (range, −1.73 to 0.27) × 10−3/min and for patients undergoing esophagogastrectomy −0.005 (range, −1.53 to 2.28) × 10−3/min. There was no statistical difference between the two groups. In the postesophagogastrectomy group, a significant elevation in circulating levels of neutrophil elastase, soluble P- and E-selectin, thrombomodulin, and von Willebrand factor antigen were observed relative to the control group but only circulating plasma elastase demonstrated a significant correlation with the PAI (r2 = .23, p =.03). ConclusionsThe data suggest patients undergoing esophagogastrectomy develop a inflammatory response but this is not a surrogate of permeability and other factors are likely to determine persistent injury to the alveolar-capillary barrier function in this patient group.


European Journal of Cardio-Thoracic Surgery | 2003

Clinical results of thoracoscopic Heller's myotomy in the treatment of achalasia.

Massimiliano Codispoti; Sing Yang Soon; Gordon Pugh; William S. Walker

OBJECTIVES Ideal treatment for achalasia permanently eliminates the dysfunctional lower oesophageal sphincter, relieving dysphagia and regurgitation. The aim of this study was to review the results in a series of patients undergoing video-imaged thoracoscopic Hellers myotomy (THM). METHODS Records of all patients undergoing THM by a single surgeon at one institution were analysed. Follow-up was conducted using a structured questionnaire together with oesophageal manometry and/or 24 h pH monitoring when clinically indicated. RESULTS Twenty-five consecutive patients (13 males, 12 females, mean age 40.3+/-19.9 years) suffering from grade 4 dysphagia underwent THM between 1993 and 2001. Preoperative mean lower oesophageal sphincter (LOS) pressure was 42.6+/-6.3 mmHg. Seven patients (28%) had undergone previous pneumatic dilatations. There were no hospital deaths and no oesophageal perforations. Length of hospital stay was 4.3+/-1.8 days. One patient died 3 years after surgery from unrelated causes. At follow-up of 5.4+/-2.1 years, freedom from any reintervention was 95.8% (23/24). Eleven patients (45.8%) were asymptomatic. In patients with residual or recurrent symptoms (n=13), their severity was significantly reduced from the preoperative period (dysphagia score 1.7+/-0.8 versus 4+/-0; P</=0.05). Four patients (16%) with troublesome residual or recurrent grade 3-4 dysphagia underwent repeat oesophageal manometric study, showing a mean reduction in LOS pressure from their baseline values of 46.8+/-6.1 to 30+/-5.4 mmHg (P</=0.01). One of these patients (4.2%) required repeat Hellers myotomy 1.5 years after THM. Six patients complained of troublesome postoperative heartburn; distal oesophageal acid exposure was shown to be abnormal in 3 (12.5%) of these patients and all enjoyed symptomatic relief with medical therapy. CONCLUSIONS THM is a safe and effective procedure in the treatment of achalasia. Some patients do experience recurrence of symptoms; however, these are significantly less severe. The incidence of postoperative heartburn is acceptably low and can be controlled with oral medications, making the addition of an anti-reflux procedure not necessary. Longer-term follow up and randomised studies comparing THM to other therapeutic modalities are needed to ascertain respectively the durability of this approach and its relative advantages.


European Journal of Cardio-Thoracic Surgery | 2003

Sequential VATS lung volume reduction surgery: prolongation of benefits derived after the initial operation.

S.Y. Soon; G. Saidi; M.L.H. Ong; A. Syed; M. Codispoti; William S. Walker

OBJECTIVE Sequential lung volume reduction (LVR) is thought to provide additional and prolonged benefit compared with unilateral LVR. We tested this hypothesis by reviewing physiological, subjective and survival outcome data on patients who underwent sequential or unilateral LVR. METHODS LVR was performed as a unilateral video-assisted thoracoscopic surgery (VATS) procedure, with bilateral reduction being undertaken in a staged manner. Pulmonary function data were collected prospectively. A telephone survey of patients and general practitioners was used to determine quality of life and survival. RESULTS Fifty patients underwent LVR. Twenty-one patients had staged reduction of the contra-lateral lung at a median interval of 9 months. Pre-operatively, patients undergoing sequential LVR were not significantly different from patients undergoing unilateral LVR: forced expiratory volume in 1 s (FEV1) 23% predicted vs. 27% predicted, KCO 40% vs. 45%, total lung capacity (TLC) 124% vs. 121%, residual volume (RV) 217% vs. 214%, health score 34.5 vs. 30.8. After single-side LVR, both groups demonstrated equivalent and significant improvement in spirometric and subjective health scores: FEV1 +15% predicted (P<0.01), TLC -5% (P=0.03), health score +80% (P<0.01). Patients undergoing sequential reduction demonstrated no further significant improvements using either an intragroup comparison with their pre-second operation values or an intergroup comparison with the unilateral LVR patients. However, sequential LVR appeared to prolong the benefits experienced after the initial surgery by 1 year. Overall, 12 patients (24%) died during follow-up with no survival difference between the two groups (P=0.65). CONCLUSION Sequential LVR is a safe strategy. Undertaking LVR to the second side does not further improve spirometric or subjective performance but does prolong the benefits achieved with the initial reduction.


Case Reports | 2011

Mediastinal paraganglioma: time to panic?

Constantinos A Parisinos; Fiona M. Carnochan; Maria L Gregoriades; Hannah Monaghan; Dilip Patel; William S. Walker

Paragangliomas (extra-adrenal phaeochromocytomas) are tumours arising from extra-adrenal chromaffin tissue. The authors describe a case of a 54-year-old woman presenting with shortness of breath and chest pain. CT pulmonary angiogram demonstrated a mediastinal mass. Further history taking revealed spontaneous attacks of headaches and palpitations. Subsequent imaging and biochemical testing confirmed the presence of a rare posterior mediastinal paraganglioma. The patient was prepared for surgery. A left thoracolaparotomy was performed and the mass was excised in its entirety. Postoperatively, 24-h urine collections showed normal normetanephrine and metanephrine levels. Since then, yearly catecholamine levels remain within the normal range.

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A. Syed

Edinburgh Royal Infirmary

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A.H. Kitchin

Edinburgh Royal Infirmary

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Dilip Patel

Edinburgh Royal Infirmary

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Douglas West

Edinburgh Royal Infirmary

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Edwin Woo

University of Edinburgh

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