Radial artery as a conduit for coronary artery bypass graft.

Since its resurgence in the 1990s, some 30 years after its abandonment as an alternative conduit, the radial artery has rapidly gained popularity. This article describes the application of this conduit in coronary grafting and details the controversies surrounding its use. A historical account as well as technical aspects such as operative technique are also discussed.

Fatigue strength of a wire passing through a cannulated screw: implications for closure of the sternum following cardiac surgery.

It has been proposed that the incidence of sternal dehiscence can be decreased by passing the wires used for sternotomy closure through cannulated screws. However, there is a potential risk of fatigue failure as a result of the wire moving against the screw, e.g. during coughing and sneezing. The system of cannulated screws and wire was subjected to static tensile testing to failure. Five tests were performed and failure occurred at 388 +/- 34 N (mean +/- SD). Ten cyclic tests were then performed. Sinusoidal loading was applied at 10 Hz with peak forces in the range 10-90 per cent of the static failure force, at a constant load ratio R = 10. The test with the lowest peak force reached run-out at 6 x 10(6) cycles. The others failed by the ends of the wire closures becoming untwisted (one test), the wire fracturing at the twist (three tests) or the wire fracturing at the screw (five tests). However, calculations based on these results suggest that fatigue failure is unlikely to occur as a result of regular breathing or continuous coughing or sneezing.

Minimal access mitral valve replacement.

Minimally invasive mitral valve surgery has recently been advocated as an alternative to the conventional median sternotomy approach. It has several documented advantages and requires a close relationship betweeen the surgeons, anaesthetist and perfusionist for a successful outcome. This article demonstrates our surgical technique for replacement of the mitral valve. The various aspects of the specialised equipment used are also described.

Hospital re-admission in children with non-specific abdominal pain.

In children with non-specific abdominal pain (NSAP) who were subsequently re-admitted to hospital with a further episode of pain within 30 days, the contribution of active observation to the initial and subsequent admission was evaluated and the diagnostic process reviewed. The cohort comprised all children with a discharge diagnosis of NSAP admitted to Royal Aberdeen Children's Hospital between January 1990 and December 1999. Data were extracted from a computerised database. A measure was made of the investigations employed in the children who were re-admitted and an arbitrary score produced in an attempt to measure the intensity and degree of the diagnostic process. This investigation score was then related to both clinical outcome and the need for revision of the original diagnosis of NSAP. A total of 1,238 children (675 males, 563 females) were admitted with NSAP; 46 (22 males and 24 females, age range 4-14 years) were re-admitted with further abdominal pain within a 30-day period. The total number of re-admission events was 53. In 19 children the subsequent diagnosis was revised. Ten of the 46 children underwent an operation; in 31 cases re-admission investigations were more detailed and invasive, but contributed to a change in diagnosis in only 13. There was no recorded mortality over the study period. In children re-admitted with abdominal pain, the subsequent diagnosis thus changed from the original in over one-third of cases. Most children undergo more invasive and more detailed investigations on re-admission in comparison to the initial episode of hospitalisation. The majority, however, continue to be managed conservatively. This study endorses the continued use of active observation in the management of NSAP in children, and recognises that even intense investigation may fail to contribute to a more specific diagnosis.

Finite element analysis of stress around a sternum screw used to prevent sternal dehiscence after heart surgery.

The sternum screw has been proposed as a means of preventing sternal dehiscence, following heart surgery, by increasing the contact area between the wire used to close the median sternotomy and the surrounding bone; as a result, the contact stress is reduced. A finite element model was constructed of a cylindrical wire or screw passing through a block of sternum which consisted of cancellous bone sandwiched within a cortical shell. The thickness of the cortical shell and the material properties of bone were varied between reasonable values. The stress distribution in the sternum was calculated for each model when the wire was subjected to a tension (250 N) which would be required for six wires to withstand a strong cough (40 kPa). Results were validated by comparison with a simple analytical model in which the bone and wire were considered incompressible. They show that the screw reduces the contact stress to almost one-seventh of its value when wire is used alone. Contact stresses are especially high if the cortical shell is thin. The high stress in the bone around a screw falls off within a few millimetres. As a result, no problems are anticipated in placing six screws in each half-sternum so that the sternotomy may be closed with the usual six wires.

A leiomyosarcoma of the oesophagus presenting incidentally without dysphagia.

Leiomyosarcoma is a rare tumour that accounts for 0.5% oesophageal sarcomas. The most common presenting symptom is dysphagia. This report presents a case of oesophageal leiomyosarcoma in a 56-year-old Caucasian man found incidentally while being investigated for refractory cough. There was no history of dysphagia in spite of tumour mass occupying most of the oesophageal lumen. The leiomyosarcoma was managed successfully with surgical resection and adjuvant radiotherapy. The patient remains disease free after 15 months after surgical intervention. The unusual case presentation is discussed and the surgical management of this rare condition reviewed.

Discrepancies in the detection and management of spontaneous pneumothorax: eight years after publication of guidelines.

The British Thoracic Society (BTS) guidelines for the detection and management of spontaneous pneumothorax have been published for over eight years. The condition continues to be managed by surgical and medical staff, especially in DGH settings. This study evaluates any recognition and initial management discrepancies in a uncomplicated pneumothorax case and documents any deviancies from guidelines A study involving 112 staff was performed in a DGH. Results showed poor overall recognition of any published guidelines (32%) with only six staff correctly identifying BTS guidelines. There was no difference between medical and surgical or consultant and junior staff in the management strategy. A tendency to initially over-treat the condition with invasive chest drainage rather than aspiration was noted. Also, there was a tendency to underestimate the size of collapse using percentages. The need for greater appreciation of detection and management of this common condition remains extant and must be addressed aggressively.

Lessons to be learned: a case study approach. 'Spontaneous' intraperitoneal bladder rupture in a psychiatric patient--with diagnostic difficulties.

The case described here is that of a 34-year-old woman with a psychiatric disorder who was referred to the local surgical receiving unit with abdominal pain and vomiting. She remained well and fully mobile but refused blood investigations until the day following admission. At that time the tests showed a picture of acute renal failure. With the development of increasing abdominal tenderness and pyrexia she was persuaded to have a laparotomy which demonstrated a small tear at the dome of the bladder. Her deranged blood biochemistry returned to normal within 11 h following surgery. The important points demonstrated in this case study are the special clinical difficulties encountered in psychiatric patients, which may consequently lead to delay in diagnosis. This delay allowed significant peritoneal reabsorption of urea and creatinine, which masqueraded as 'acute renal failure' on biochemical testing. The case also highlights the use of procyclidine, commonly used in patients with psychiatric disorders; urinary retention is a recognised side effect of this drug--and it is possible that such retention together with a minor and hence easily overlooked episode of trauma, may have contributed to the patient's condition.

Preoperative assessment of primary varicose veins: a duplex study of venous incompetence.

OBJECTIVES: we investigated the importance of preoperative duplex scanning in primary uncomplicated varicose vein surgery by evaluating the incidence of superficial venous imcompetence and significant anatomical variations that may be difficult to detect clinically and therefore might be expected to contribute to recurrence. DESIGN: a retrospective study of a prospectively collected database. MATERIALS: over 15 consecutive months, patients attending the non-invasive vascular laboratory for duplex scanning of their primary uncomplicated varicose veins were assessed. METHODS: vascular laboratory case notes were assessed and incidence of superficial venous incompetence and any significant anatomical variations that would have been difficult to detect clinically +/-HHD were documented. Any correlation with clinical findings was also evaluated. RESULTS: a total of 223 limbs (176 patients) were assessed. Sixty-seven limbs (30%) in fact had a competent sapheno-femoral junction. Sixty-one limbs (27%) had pure sapheno-femoral reflux and nil else. Fifty-three limbs (24%) had significant anatomical variations. Forty-two limbs (19%) had short saphenous vein incompetence, of which 67% were clinically unsuspected. CONCLUSIONS: preoperative duplex scanning is indicated in all patients with uncomplicated primary varicose veins if appropriate venous surgery is contemplated. There are obvious resource and recurrence rate implications. Further evaluation in the form of randomised trials are required.

Use of clinical audit for revalidation: is it sufficiently accurate?

In order to provide better patient care, clinicians will be subject to revalidation and re-certification. This may be partially based on existing and ongoing data collection, yet many units fail to incorporate mechanisms that validate the data that may be used. The accuracy of audit data was evaluated in a unit that has been using commercially available audit software for over 10 years. A total of 655 consecutive surgical admissions were documented over a 6-month period and errors in data collection and entry were gathered and analyzed. An overall accuracy of 90.5% was confirmed but examination of the data found them to be open to misinterpretation. Moreover, 13% of errors were made during a single week when locum staff were involved. The study highlights the fallibility of data collection during audit, and urges caution if using such data when judging performance-related issues as part of the process of appraisal.

Serum cytokine profile in reflux nephropathy.

Cytokines are small regulatory peptides with diverse functions. They regulate the immune system and modulate the inflammatory response, both of which are implicated in vesico-ureteric reflux (VUR) and associated reflux nephropathy (RN). The cytokine profile in VUR and RN has yet to be fully investigated. Blood was obtained from three subject groups immediately after induction of anaesthesia: group A [subjects with VUR and established RN, (N=9)]; group B [VUR alone but no associated RN, (N=6)]; and group C [age- and sex-matched controls with no history of urinary sepsis, (N=14)]. Serum cytokine levels of tumour-necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), soluble TNF receptor-1 (sTNF-R1), and interleukin-8 (IL-8) were measured using standard ELISA technique. Serum levels of IL-6 were higher in group A subjects (1.798-4.638 pg/ml, median 3.253 pg/ml) than controls (1.531-2.078 pg/ml, median 1.798 pg/ml). There was no significant difference in levels in group B subjects (1.498-3. 048 pg/ml, median 1.948 pg/ml) and controls. These same relationships were observed for levels of TNF-alpha (group A: 8. 501-14.471 pg/ml, median 13.483 pg/ml; group B: 7.088-10.650 pg/ml, median 8.886 pg/ml; group C: 6.746-13.344 pg/ml, median 7.671 pg/ml) and sTNF-R1 (group A: 690.34-5780.74 pg/ml, median 1197.38 pg/ml; group B: 366.65-1401.62 pg/ml, median 592.82 pg/ml; C: 313.49-636.33 pg/ml, median 504.17 pg/ml). IL-8 was not significantly elevated in any of the study groups (A or B) compared with control group C (group A: 27.08-56.38 pg/ml, median 31.35 pg/ml; group B: 29.90-35. 87 pg/ml, median 31.35 pg/ml; group C: 25.05-30.22 pg/ml, median 29. 90 pg/ml). These results suggest there may be an immunological basis to RN.

Urinary cytokines as markers of reflux nephropathy.

PURPOSE: We established whether the urinary cytokines interleukin-6 (IL-6), tumor necrosis factor (TNF)-alpha and soluble TNF receptor-1 have a role as noninvasive markers of renal damage in children with vesicoureteral reflux. MATERIALS AND METHODS: We performed an observational study in a surgical and urological unit at a pediatric teaching hospital. Urine cytokine levels of IL-6, TNF-alpha and soluble TNF receptor-1 were measured using a standard enzyme-linked immunosorbent assay technique in children stratified into group 1--11 with vesicoureteral reflux and reflux nephropathy, group 2--6 with vesicoureteral reflux only and no associated nephropathy, and group 3--15 age and sex matched controls. RESULTS: Urinary levels of the cytokines IL-6 and soluble TNF receptor-1 were significantly elevated in group 1 versus group 3 (0.048 to 13.25 pg./micromol. creatinine, mean 3.658 versus 0.027 to 0.677, mean 0.247 and 102.89 to 4,502.9 pg./micromol. creatinine, mean 1,395.3 versus 13.06 to 569.6, mean 145.357, respectively). Neither cytokine in group 2 (0.074 to 10.96 pg./micromol. creatinine, mean 2.94 and 51.52 to 1,115.48, mean 413.137, respectively) was elevated compared to that in group 3. TNF-alpha was not elevated in group 1 or 2 compared to that in group 3 (0.104 to 2.518 pg./micromol. creatinine, mean 0.56, 0.094 to 1.278, mean 0.334 and 0.065 to 0.694, mean 0.241, respectively). CONCLUSIONS: Measuring the urinary levels of the cytokines IL-6 and soluble TNF receptor-1 may be useful as a noninvasive marker of reflux associated renal damage. Further studies with larger patient groups are necessary to locate the source of production of the elevated urinary cytokines measured in our study.