Surgical factors in the prevention of infection following major lower limb amputation.

OBJECTIVES: Infection following major lower limb amputation is common but surgical influences on the rates of infection are not known. We aim to assess the influence of peri-operative surgical factors on outcome. DESIGN AND METHODS: Review of a prospective database included all patients undergoing a major lower limb amputation from March 2008 to July 2010. Infection was classified using Centre for Disease Control criteria and multivariate analysis performed to identify significant risk factors. RESULTS: 127 patients, median age 78 yrs (31-98) were included. 34.6% of patients developed a wound infection following surgery; 47.7% of which were classed as superficial incisional surgical site infections, with 52.3% being deep incisional surgical site infections. There was a higher infection rate in below knee than above knee amputations (p < 0.001). There was no relationship between the grade of the operating surgeon (p = 0.829), peri-operative antibiotics (p = 0.933), length of operation (p = 0.651), use of nerve catheter (0.267) and the post-operative presence of infection. There was a higher rate of infection with the use of suction drains (p < 0.05). The use of skin clips rather than sutures was associated with an increased rate of infection (p < 0.05). There was an increased need for revision surgery with the use of skin clips, although this was not significant (p = 0.07). CONCLUSIONS: Skin clips and surgical drains adversely influence the risk of infection in major limb amputation and their use should be avoided.

Improving the accuracy of self-assessment of practical clinical skills using video feedback--the importance of including benchmarks.

INTRODUCTION: Isolated video recording has not been demonstrated to improve self-assessment accuracy. This study examines if the inclusion of a defined standard benchmark performance in association with video feedback of a student's own performance improves the accuracy of student self-assessment of clinical skills. METHODS: Final year medical students were video recorded performing a standardised suturing task in a simulated environment. After the exercise, the students self-assessed their performance using global rating scales (GRSs). An identical self-assessment process was repeated following video review of their performance. Students were then shown a video-recorded 'benchmark performance', which was specifically developed for the study. This demonstrated the competency levels required to score full marks (30 points). A further self-assessment task was then completed. Students' scores were correlated against expert assessor scores. RESULTS: A total of 31 final year medical students participated. Student self-assessment scores before video feedback demonstrated moderate positive correlation with expert assessor scores (r = 0.48, p < 0.01) with no change after video feedback (r = 0.49, p < 0.01). After video feedback with benchmark performance demonstration, self-assessment scores demonstrated a very strong positive correlation with expert scores (r = 0.83, p < 0.0001). CONCLUSIONS: The demonstration of a video-recorded benchmark performance in combination with video feedback may significantly improve the accuracy of students' self-assessments.

Popliteal venous aneurysm causing pulmonary embolism and paradoxical embolisation in a patient with antiphospholipid syndrome.

INTRODUCTION: Popliteal venous aneurysms are rare and can cause recurrent pulmonary emboli despite adequate anticoagulation. REPORT: A 43-year old patient with known antiphospholipid syndrome developed an extensive pulmonary embolus and ischaemic stroke despite anticoagulation. Duplex ultrasound confirmed a right popliteal venous aneurysm containing non-adherent multi-layered thrombus. At operation an 8 cm x 5 cm true aneurysm of the popliteal vein was excised. A postoperative echocardiogram revealed a patent foramen ovale. DISCUSSION: This case is unusual as the patient suffered a paradoxical embolism due to his patent foramen ovale. Although antiphospholipid syndrome is associated with venous thrombosis, this is usually prevented by therapeutic anticoagulation.

Fibrin deposition in autochthonous Syrian hamster pancreatic adenocarcinomas induced by the chemical carcinogen N-nitroso-bis(2-oxopropyl)amine.

Immunofluorescence studies have demonstrated the presence of fib (a group of fibrinogen- and fibrin-related proteins that react with antibodies raised against fibrinogen) in the stroma of several transplantable animal and autochthonous human tumors. Acceptance of these reports was tempered by the possibility of artifactual clotting and fibrinolysis associated with tumor removal or tumor transplantation and by the relatively poor histology inevitable when immunofluorescence is performed on frozen tissue sections. An immunoperoxidase study therefore was undertaken of the ductal pancreatic carcinomas induced in female LGV Syrian hamsters by N-nitroso-bis(2-oxopropyl)amine [(BOP) CAS: 60599-38-4]. Artifactual clotting and fibrinolysis associated with tumor removal were avoided by systemic anticoagulation and antifibrinolysis. Fibronectin and residual fib were prominent components of tumor stroma. Prominent fib deposits also were found in a new location: the basement membrane zones of atypical pancreatic ducts and invasive carcinomas. In contrast, fib deposits were never found in the basement membranes of blood vessels, nerves, or pancreatic acini of BOP-treated or normal animals, or in the ductal basement membranes in the normal pancreas. Ducts with marked atypicality and invasive pancreatic carcinomas frequently exhibited discontinuous basement membrane staining for fib, which often paralleled loss of staining for the integral basement membrane proteins--type IV collagen and laminin. Loss of acquired fib basement membrane staining with malignant disease progression may serve as a new marker for local tumor invasion.

Augmentation of 1,2-dimethylhydrazine-induced colon cancer by experimental colitis in mice: role of dietary vitamin E.

Because ulcerative colitis predisposes to colonic cancer, for determination of the effect of colitis on experimental colon carcinogenesis, rectal instillations of peptides that attract and activate neutrophils were used to induce colitis in CD-1 (ICR) BR mice receiving 20 weekly injections of the carcinogen 1,2-dimethylhydrazine [(DMH) CAS: 540-73-8]. From week 4 through week 15 of DMH injections, twice-weekly enemas of formyl-norleucyl-leucyl-phenylalanine were given to DMH-treated mice. The effect of the antioxidant vitamin E in the diet (1,750 IU/kg diet) was studied in another group of mice treated with DMH and having colitis. Four weeks after DMH was discontinued, cancer occurred in 9 of 28 (32%) animals with DMH plus control enemas, in 22 of 29 (76%) animals with DMH plus colitis (P = .001), and in 16 of 28 (57%) animals with DMH plus colitis plus supplemental vitamin E (P = .11 compared with the group with DMH and colitis). Colitis enhances DMH-induced colonic carcinogenesis.

Pancreatic cancer in the Syrian hamster induced by N-nitrosobis(2-oxopropyl)-amine: cocarcinogenic effect of epidermal growth factor.

Because epidermal growth factor (EGF) is rapidly bound and internalized into rat pancreas, stimulates uptake of tritiated thymidine, and increases pancreatic weight, a cocarcinogenic effect on pancreatic cancer seemed likely. Pancreatic adenocarcinomas were induced in 70 female Syrian hamsters by 19 weekly s.c. injections of N-nitrosobis(2-oxopropyl)amine (BOP) (10 mg/kg). From Wk 5 through Wk 8 of BOP injections, additional s.c. injections of EGF (5 micrograms every 3 days for 10 injections) were given to 45 animals, while 25 received saline solution. An additional group of 10 received EGF alone, and another 10 animals received saline solution alone (controls). Eleven wk later, the mean body weight of EGF-treated animals increased by 29% as compared with that of controls, and their mean pancreatic weight relative to body weight increased by 44% as compared with controls. The mean body weight of EGF + BOP-treated animals increased by 10%, and their pancreatic weight relative to body weight increased by 22% as compared with that of animals treated with BOP alone. The incidence of pancreatic cancer in the EGF + BOP-treated animals was 75% versus 44% in those treated with BOP alone (P = 0.016). No tumors developed in either animals treated with EGF alone or control animals. EGF augments pancreatic carcinogenesis induced by BOP. The incidence of bronchial carcinomas doubles.

Implantable device for drug delivery and blood sampling in the rat.

An implantable drug-delivery and venous sampling device is described that is constructed from a polyvinyl chloride catheter and a rubber intravenous catheter plug coated with Silastic. The implant was used for repeated venous sampling and for both administration of parenteral solutions and injections into the right colon of the rat for periods to 1 mo.

Intestinal obstruction by overdistension of a jejunostomy catheter balloon: a salutary lesson.

Jejunostomy is an alternative method for feeding patients who cannot be fed orally. However, there may be an associated morbidity and potential mortality. In the case presented, overdistension of a jejunostomy catheter balloon led to intestinal obstruction and pressure necrosis (of the small bowel), with subsequent abscess formation leading to death from septicemia.

PTFE, collars, and patches.

The results of PTFE grafts to crural vessels have been sufficiently poor for some surgeons to consider primary amputation for critical ischemia in the absence of suitable lengths of autologous vein from arm or leg. However, the results of two anastomotic techniques using a short segment of interposed vein, are encouraging. We have attained 1-year patency rates of 74% (n = 72) using PTFE with the Taylor patch technique (personal communication) and 47% (n = 27) using PTFE with Miller collar anastomoses to distal crural vessels. To investigate the hemodynamic benefit of these techniques, they have been tested (using a pulsatile flow model incorporating standard pressure, viscosity, graft and vessel length, and anastomotic angle) against a standard end-to-side PTFE anastomosis to cadaver internal mammary artery. There was no significant difference in flow between the anastomotic methods. Downstream resistance was dictated by the diameter of the recipient vessel providing a vein interposition technique was used (r greater than .80), but this relationship was lost if a direct PTFE-arterial anastomosis was performed (r = .06), suggesting additional anastomotic resistance in the latter. This constitutes experimental evidence to suggest that direct PTFE-arterial anastomosis risks hemodynamically important technical errors, which are avoidable by the use of either the Miller collar or Taylor patch.

Method of one-way surgical drainage for the inexpensive accurate measurement of abdominal secretions.

A simple, inexpensive method for one-way collection and measurement of secretions is described. This method has been used successfully in surgical practice in Bath for more than 20 years (1).

Partial amputations of the foot for diabetic gangrene.

Over a 5-year period 68 diabetic patients underwent 102 primary partial amputations of the foot for infected diabetic gangrene. Seventy (69%) of these operations healed without further local surgery, but five patients needed seven femoropopliteal bypass grafts (two bilateral) to achieve healing. In total, 32 primary operations needed revision by further surgery to the foot or by leg amputation. Of the original operations 31% were carried out by a consultant surgeon; the rest (69%) were performed by a junior surgeon. By contrast, only four of the 32 operations needing revision (12%) had originally been done by a consultant, whereas 28/32 (88%) had been carried out by a junior surgeon. Of limbs at risk 65/80 (81%) were salvaged. Five patients died during their hospital admission, giving an overall mortality of 7%.

Meatal strictures after transurethral prostatectomy using latex or polyvinyl chloride three-way catheters.

Because latex rubber catheters have been implicated in urethral stricture formation, the incidence of urethral strictures following transurethral prostatectomy (TUP) and subsequent catheterisation with latex rubber or polyvinyl chloride catheters was compared. A total of 84 patients with benign prostatic hyperplasia (n = 71) or prostatic carcinoma (n = 13) underwent assessment of urethral diameter and subsequent internal urethrotomy prior to TUP. Following resection, 42 patients received three-way self-retaining latex rubber catheters and 42 received similar catheters made of PVC. Catheters were removed when the urine was clear (mean time = 3 days), and no patient required recatheterisation. Urinary flow was assessed in all patients at 6, 12 and 24 weeks after surgery, and diminution of flow with submeatal stricture formation was noted in one patient who had received a latex rubber catheter, and in one who had received a PVC catheter. In this study, the composition of the catheter had no bearing on subsequent stricture formation following TUP.

Vascular reconstruction at the groin: oblique or vertical incisions?

Incisions for vascular access at the groin are usually vertical. Because such incisions cross the moist skin-crease area and disrupt lymphatics, they may be more prone to infection than oblique incisions placed above and parallel to the groin crease. To determine whether this was the case, 149 patients undergoing vascular reconstruction through a groin incision over a period of 30 months were studied. Those with previous groin incisions were excluded, and where an incision was necessary in both groins, each wound was studied separately. Over a 10-day postoperative period 5 of 85 vertical wounds developed infection with purulent discharge, whereas no oblique wounds (n = 82) became infected (P = 0.032). Oblique incisions for vascular access at the groin are associated with a decreased incidence of wound infection compared with conventional vertical incisions.

Management of varicose veins according to reason for presentation.

Of 229 newly referred patients with varicose veins, untoward symptoms were the most frequent reason for presentation (38%). Cosmetic concerns were significantly more common in women than in men (33% vs 8%, P < 0.001). Sclerotherapy was offered to 20 patients (8.7%). Surgical operation was offered in 113 (49.3%), mostly for symptoms. No invasive treatment was indicated in 96 patients (42%), more than half of whom had presented because of inappropriate fears of deterioration or with symptoms unrelated to their veins. We advocate that careful evaluation of the reasons for presentation should be used as a guide to the efficient management of varicose veins.

The effect of cephradine prophylaxis on wound infection after arterial surgery through a groin incision.

Cephradine administered prophylactically to a group of 35 patients undergoing reversed saphenous vein femoro-popliteal bypass, iliofemoral endarterectomy or profundaplasty through a groin incision, resulted in a significant reduction in the incidence of wound infection (P = 0.025; exact probability test). One gram of cephradine was given at induction of anaesthesia, followed by three postoperative doses of one gram at 6 hourly intervals. The overall wound infection rate at 7 days, as assessed by frank purulent discharge, was 15%. After cephradine prophylaxis, no infections were noted as judged on this basis, but erythema of the suture line was seen in equal numbers (40% of each group). Where the indication for operative intervention was rest pain or gangrene, the incidence of wound infection was very much increased, 80% of the infected cases being from this group.

Wound perfusion with bupivacaine: objective evidence for efficacy in postoperative pain relief.

Conflicting reports exist for the efficacy of intermittent wound perfusion with bupivacaine in the relief of postoperative pain. A study was devised to assess postoperative pain relief objectively using a Patient Controlled Analgesic Device (PCAD) during continuous wound perfusion with bupivacaine or saline. Thirty consecutive patients undergoing cholecystectomy were randomised to receive continuous postoperative wound perfusion with 0.5% bupivacaine for 24 h followed by normal saline for a further 24 h or vice versa. During the study period, conventional analgesia was provided using a PCAD set to deliver (and record the number of) on-demand bolus doses of intravenous pethidine 0.2 mg/kg at half-hourly intervals as required. Pethidine requirements were higher on the first postoperative day, regardless of which solution was given, but bupivacaine perfusion almost halved mean linear analogue pain scores compared to those recorded with saline. Likewise, the number of bolus doses of pethidine demanded was reduced by an average of 68% compared to those recorded during saline perfusion on day 1 (P = 0.01) and by 82% on day 2 (P = 0.01). When assessed by objective criteria, perfusion of surgical wounds with bupivacaine after cholecystectomy produces better pain relief than wound perfusion with saline.

Surgical palliation for pancreatic cancer: will biliary bypass alone suffice?

Because a number of options are available to relieve the obstructed bile duct, stomach or both in patients with irresectable carcinoma of the pancreatic head, palliative surgery for this condition was reviewed retrospectively between 1971 and 1981 at the Royal United Hospital, Bath. One hundred and sixty-five patients underwent a biliary bypass procedure with (n = 37), or without (n = 128) gastric drainage. Thirty patients had a prophylactic gastroenterostomy to avoid gastric outlet obstruction: tumour encroachment made gastroenterostomy essential in seven others. After biliary bypass alone, operative mortality was 14%. After a concomitant gastroenterostomy, mortality was 27% (P less than 0.04). Within a year of biliary bypass alone, there was a 9% incidence of gastric outlet obstruction requiring gastric drainage, with an associated mortality rate of 18%. Survival after biliary bypass or biliary bypass with gastroenterostomy was equal (7-8 months). Except where gastric outlet obstruction is imminent, palliation for irresectable pancreatic head carcinomas should be by biliary bypass alone, because the addition of a gastroenterostomy almost doubles the mortality without any advantage in survival time.

Ruptured aneurysm of the common iliac artery as a cause of unilateral hip pain.

Rupture of an aneurysm of the common iliac artery is a rare cause of pain in the hip. We describe an elderly hypertensive patient with an aneurysmal rupture of the left common iliac artery who presented with unilateral hip pain masquerading as septic arthritis.