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Biomedical subjects

John H N Wolfe

Publications and source records attributed to John H N Wolfe.

6 recordsLinked to original sources

Technical skills continue to improve beyond surgical training.

BACKGROUND: There is growing focus on surgical technical competence and the means by which we are able to measure it. Ongoing studies have shown a plateau effect with increasing experience of the operator. The aim of this study was to assess the technical competence of five groups of surgeons with increasing experience and validate a new rating tool for use in surgical assessment. METHODS: Fifty surgeons performed a saphenofemoral junction ligation on a synthetic groin model. The procedure was videotaped, blinded, and reviewed independently by three assessors. Performance was assessed using a previously validated global rating scale of generic surgical skill. In addition, each procedure was rated with the procedure-specific Imperial College Evaluation of Procedure-Specific Skill (ICEPS) rating scale to establish the construct validity (ability to differentiate on the basis of skill) and inter-observer reliability. RESULTS: Both rating scales showed improved scores with ascending grades (P < .001) and demonstrated a high inter-observer reliability both for generic and procedure-specific skill (alpha = 0.97 and alpha = 0.96, respectively). Total operative scores demonstrated significant differences between surgeons in postgraduate years 1 and 2 and surgeons in years 3 and 4 and also between newly appointed and experienced consultants (P < .041). Procedure-specific performance showed a plateau effect at the registrar level. Generic skill continued to improve, and significant differences were seen between newly appointed and senior consultants (P < .026). CONCLUSION: This study shows that surgical performance continues to improve significantly beyond consultancy, and the data suggest that generic and procedural performance continue to improve, with significant improvement in the former with increasing experience. The ICEPS rating scale demonstrates construct validity and a high inter-observer reliability supporting its use in formative and summative assessment.

Clinical Competence↗

Complex thoracoabdominal aortic aneurysms: endovascular exclusion with visceral revascularization.

OBJECTIVE: We review our ongoing experience with a transabdominal stent repair of complex thoracoabdominal aneurysms (Crawford type I, II, and III) with surgical revascularization of visceral and renal arteries. METHODS: A retrospective review was conducted of prospectively collected data from 29 consecutive patients who underwent an attempted visceral hybrid procedure between January 2002 and April 2005. Twenty-two patients were elective, four were urgent (symptomatic), and three were emergent (true rupture). The median patient age was 74 years (range, 37 to 81 years). The aneurysms were Crawford type I in 3, type II in 18, type III in 7, and type IV in 1. Previous aortic surgery had been performed in 13 (45%) of 29 and included aortic valve and root replacement in 3, TAA repair in 1, type I repair in 1), type IV repair in 3, type B dissection in 2, infrarenal aneurysm in 5, and right common iliac aneurysm in 1. Severe preoperative comorbidity was present in 23 (80%) of 29: chronic renal impairment in 5, severe chronic obstructive pulmonary disease in 6, myocardial disease in 11 at New York Heart Association grade II (6) and grade III (5), and Marfan's syndrome in 6. Twenty-six patients (90%) had a completed procedure. In two patients, myocardial instability prevented completion of the procedure despite extensive preoperative cardiac assessment, and in one, poor flow in the true lumen of a chronic type B dissection prevented anastomosis of the revascularization grafts. Exclusion of the full thoracoabdominal aorta was achieved in all 26 completed procedures and extended to include the iliac arteries in four, with revascularization of coeliac in 26, superior mesenteric artery in 26, left renal artery in 21, and right renal artery in 21). RESULTS: There was no paraplegia < or =30 days or during inpatient admission, and elective and urgent mortality was 13% (3/23). All of the patients with ruptured thoracoabdominal aneurysms died < or =30 days. Major complications included prolonged respiratory support (>5 days) in 9, inotropic support in 4, renal impairment requiring temporary support in 2 and not requiring support in 2, prolonged ileus in 2, resolved left hemispheric stroke in 1, and resection of an ischemic left colon in 1. Median blood loss was 3.9 liters (range, 1.2 to 13 liters). The median ischemia time was 15 minutes (range, 13 to 27 minutes) for the superior mesenteric and coeliac arteries and 15 minutes for the renal arteries (range, 13 to 21 minutes). The median hospital stay was 27 days (range, 16 to 84 days). Follow-up was a median of 8 months (range, 2 to 31 months), with 92 of 94 grafts patent. Six patients were found to have a type I endoleak. In four, this was a proximal leak, and stent extension in three reduced, but did not cure, the endoleak. One patient with a distal type I endoleak was successfully treated by embolization. Four type II endoleaks resolved without intervention, and one was treated by occlusion coiling of the origin of the left subclavian artery. A single late type III endoleak was found. CONCLUSION: Early results of visceral hybrid stent-grafts for types I, II, and III thoracoabdominal aneurysms are encouraging, with no paraplegia in this particularly high-risk group of patients. These results have encouraged us to perform the new procedure, in preference to open surgery, in Crawford type I, II, and III thoracoabdominal aortic aneurysms.

Adult↗

Lower limb venous haemodynamic impairment on dependency: quantification and implications for the "economy class" position.

The role of stasis in venous disease is undisputed, yet surprisingly, its haemodynamic quantitation remains largely undefined. We investigated the phenomenon of venous stasis in the lower limb upon sitting and standing and project its implications to economy class aircraft passengers. 26 normal limbs, 13 subjects, age 29-54, selected after duplex, plethysmography and ABPI, had peak[V(peak)], mean[V(mean)] and minimum[V(min)] velocities, volume-flow[Q(venous)], pulsatility index [PI(venous)] and diameter obtained on horizontal, sitting (as in economy aircraft seats) and standing with duplex, at popliteal, femoral[FV] and common femoral[CFV]veins [differences in median %]. V(peak), V(mean) and Q(venous) decreased from horizontal to sitting in the CFV [57%, 71%, 31%, respectively], FV [51%, 70%, 34%] and popliteal [31%, 58%, 42%] (all, p<.001). V(peak),V(mean) and Q(venous) decreased further from sitting to standing in the CFV [26%, 44%, 25%, respectively], FV [21%, 42%, 27%] and popliteal [14%, 42%, 20%] (all, p <.001). Diameter, V(min) and PI(venous) increased from horizontal to sitting in the CFV [50%, 63%, 38%, respectively], FV [39%, 23%, 66%] and popliteal [21%, 14%, 84%] (all, p <.001)]. Diameter, V(min) and PI(venous) increased further from sitting to standing in CFV [10%, 22%, 19%, respectively; p =.004], FV [12%, 68%, 2%[ns]; p <.001)] and popliteal [14%, 50%, 24%; p =.017]. In all postures: V(peak), V(mean), Q(venous) and diameter at CFV exceeded FV (p <.025) and popliteal (p <.001) ones; also those at FV exceeded the popli-teal ones (p =.003), except for the diameter on horizontal. V(min) in popliteal was higher than in CFV (p =.003) or FV (p <.025), on horizontal and standing. PI(venous) in CFV was lower than in FV or popliteal (p <.025) on sitting. Right to left differences non-significant. [Wilcoxon(+Bonferroni) test: significance at p <.025] A shift from horizontal to sitting generates a most significant attenuation in Q(venous),V(peak) and V(mean) linked to a reciprocal increase in V(min), PI(venous) and vein diameter, with further exacerbation on standing. V(peak),V(mean) and Q(venous) decline with distance from groin enhancing venous stasis in the periphery. By restricting activation of the natural venous pumps, sitting cramped during long flights may protract the status of haemodynamic stagnation sustained on dependency which paired with marked venous dilatation generates a milieu that may promote thrombogenesis.

Adult↗

Cerebral hyperperfusion syndrome-a case report and literature review.

Cerebral reperfusion following carotid endarterectomy occasionally causes cerebral hyperperfusion syndrome. This is a rare but important complication and this case report acted as a stimulus for a literature review of this problem. A 60-year-old businessman had a right carotid endarterectomy for a severe stenosis which had caused recurrent attacks of amaurosis fugax. The left internal carotid artery had occluded asymptomatically. The operation and his immediate postoperative recovery were entirely uneventful but he developed right-sided headaches and focal sensory motor seizures. He subsequently recovered. Hemodynamically compromised patients appear to be at greater risk and as the mortality of the operation is reduced and more complex patients are treated, it is likely that this unusual complication will increase in incidence.

Brain↗