The impact of the establishment of a surgical high dependency unit on management of Abdominal Aortic Aneurysm

BACKGROUND

Our ability to maintain satisfactory levels of outcome after elective abdominal aortic aneurysm (AAA) surgery is increasingly strained by rising levels of co-morbidity in the presenting population. In this study we present a comparative outcome analysis of patients undergoing elective AAA surgery 18 months before and after the establishment of a surgical high dependency unit (HDU).

METHODS

The preoperative status (ASA and POSSUM scores), operative factors and postoperative outcomes as well as duration of stay were calculated for 104 patients undergoing elective AAA repair (57 prior to the HDU opening and 47 patients afterwards).

RESULTS

Patients undergoing surgery in the latter period had significantly higher ASA (2.5 +/- 0.06 versus 2.7 +/- 0.7; p = 0.007), overall POSSUM (33.2 +/- 0.5 versus 35.5 +/- 0.8; p = 0.02) and physiological POSSUM (16.3 +/- 0.3 versus 15.5 +/- 0.2; p = 0.048) scores than those operated on prior to establishment of the HDU (data are mean +/- SEM; 2-tailed p-score). The two groups had similar total lengths of hospital stay (518 versus 534 days). However, following establishment of the HDU patients occupied fewer ICU bed days (110 versus 181). This resulted in a saving of Euro 50,750.

CONCLUSION

The efficiency and quality of care following elective AAA surgery can be improved by provision of HDU step-down facilities without significantly increased expenditure.

Acute aortic occlusion in a patient with heparin-induced thrombocytopenia treated by thrombectomy

INTRODUCTION

Heparin-induced thrombocytopenia syndrome (HITS) is an infrequent complication of heparin anticoagulation.

CASE REPORT

We present the case of a 44-year-old male who was admitted with acute ischaemia of his right lower limb. He was initially treated with unfractionated heparin and thrombolysis, but subsequently developed acute aortic thrombosis 8 days following initiation of heparin therapy. This was treated with bilateral per-femoral thrombectomy with curative result.

CONCLUSION

This case report draws the attention of surgeons to the difficulties in diagnosing HITS and highlights the multidisciplinary management of a complicated case of acute ischaemia.

The Effect of Perioperative β-blockade on the Pulmonary Function of Patients Undergoing Major Arterial Surgery

INTRODUCTION

Concern about the potential detrimental side-effects of beta-blockade on pulmonary function often dissuades against their perioperative use in patients undergoing major arterial surgery (especially in those with chronic obstructive pulmonary disease (COPD)). In this study we aimed to establish prospectively the clinical relevance of these concerns.

METHODS

After ethics committee approval and individual informed consent, the pulmonary function of twenty patients (mean age 68.7 years (range 43-82), 11 males) scheduled to undergo non-emergency major vascular surgery was studied by recording symptoms and spirometry before and after institution of effective beta-blockade. Fifteen patients (75%) had significant smoking histories (mean pack years/patient=50), while 12 (60%) had COPD.

RESULTS

All patients tolerated effective beta-blockade satisfactorily without developing either subjective deterioration in symptoms or significant change on spirometry. The mean change in FEV1 following adequate beta-blockade was 0.05+/-0.24 liters (95% CI -0.06 to +1.61), p=0.35, giving a mean percentage change of 3.18%+/-11.66 (95% CI -2.26 to 8.62).

CONCLUSIONS

Previously held concerns about worsening pulmonary function through the short-term use of beta-blockers should not dissuade their perioperative usage in patients with peripheral vascular disease. Furthermore, the accuracy of pulmonary function tests in preoperative assessment and risk stratification also appears unaffected by this therapy.

Concomitant Detection of Systemic Atherosclerotic Disease while Screening for Abdominal Aortic Aneurysm

INTRODUCTION

Although population screening for abdominal aortic aneurysm (AAA) has/had a significant impact on disease-specific mortality, coexisting systemic atherosclerosis represents the major impediment to improved longevity. We examined the feasibility and yield of full cardiovascular assessment concomitant with screening for AAA detection.

METHODS

A total of 1032 asymptomatic men over the age of 50 years (328 were >60 years) underwent a detailed cardiac health questionnaire, sphygmomanometry, body mass index calculation, fasting lipid profiling, ultrasonographic (US) examination of their infrarenal aorta and carotid arteries, and treadmill exercise stress testing. Framingham and SCORE project estimations of the 10-year risk of ischemic heart disease (IHD) and fatal cardiovascular disease (CVD) of any cause were calculated for the men with an AAA and in those>60 years but with neither AAA nor known cardiac disease.

RESULTS

Overall, we detected an AAA>3 cm in 30 men (2.9%). Unaddressed obesity, smoking, hypertension, impaired glucose metabolism, and hypercholesterolemia were commonly identified in individuals both with and without an AAA, being notably frequent in those>60 years without an AAA. The 10-year risk of IHD and CHD in those>60 years was similar regardless of whether an AAA was present. Doppler screening for significant carotid stenosis had detection rates similar to those for aortic US scanning, being most useful in those>65 years of age. Exercise stress testing, however, was of only limited value when used nonselectively.

CONCLUSIONS

Modifiable atherosclerotic disease and cardiovascular risk can be readily detected in individuals presenting for AAA screening and are present to a significant degree at an earlier age. Consideration of selected, additional investigations is required to maximize the value of generalized screening programs.

Malignant Fibrous Histiocytoma Masquerading as a Psuedoaneurysm of the Profunda Femoris

We describe a patient with an aggressive soft tissue sarcoma masquerading as a profunda femoris pseudoaneurysm. A 73-year-old patient presented with a pulsatile swelling in her right groin. Femoral angiography demonstrated what appeared to be a pseudoaneurysm of the right profunda femoris artery and she underwent an open surgical repair. The patient represented 2 months later with an enlarging non-pulsatile, non-tender mass at the site of the wound. Open biopsy determined the diagnosis as malignant fibrous histiocytoma (MFH). An en bloc resection of the mass with reconstruction of the femoral artery and vein using PTFE grafts was performed.

A prospective, randomised trial of preoperative rectal diclofenac: Are we closing the gate after the horse has gone?

BACKGROUND

Diclofenac sodium is a non-steroidal anti-inflammatory agent commonly used to provide analgesia post-surgery. It is common clinical practice to administer a diclofenac suppository at induction to contribute to pre-emptive analgesia (PEA). Diclofenac takes up to 30 minutes to attain maximal plasma level after rectal administration.

AIM

To compare post-operative analgesia in patients who received diclofenac 30-45 minutes preoperatively, or at induction of anaesthesia.

METHODS

A prospective, randomised, double-blind controlled trial in 157 patients undergoing varicose vein surgery. Group A (control) received a rectal placebo 30-45 minutes preoperatively, group B received diclofenac 100 mg 30-45 minutes preoperatively and group C received placebo 30-45 minutes preoperatively and diclofenac 100 mg at induction. Outcome measures were Visual Analogue Scores (VAS) and requirement for rescue analgesia.

RESULTS

Patients in group A had significantly poorer analgesia than patients in groups B and C. There were no significant differences in VAS values and requirements for rescue analgesia between groups B and C 3-4 hours and 18-22 hours postoperatively.

CONCLUSION

For patients undergoing varicose vein surgery preoperative administration of rectal diclofenac significantly improves post-operative analgesia and this effect is independent of whether it is given at induction or 30-45 minutes preoperatively.

Angiogenesis in carotid atherosclerosis: the association with morphological features of plaque instability

Background

Intimal angiogenesis is a recognized feature of the atherosclerotic process. It has been described in the context of unstable coronary atherosclerotic lesions. The aims of this study were to assess the association between angiogenesis in atherosclerotic plaques and microscopic features of plaque instability, in particular intraplaque haemorrhage.

Methods

Consecutive patients undergoing carotid endarterectomy for carotid stenosis were included in the study. Endarterectomy specimens were examined and divided into their constituent atherosclerotic lesions. Histological sections were prepared and stained with haematoxylin and eosin, and immunohistochemically with an endothelial cell marker (CD34). Each lesion was classified according to the American Heart Association classification of atherosclerotic lesions. The size of plaque haemorrhage was measured in transverse histological sections using computerized image analysis. Haemorrhagic lesions were classified according to the size of haemorrhagic area (under 50 per cent of section area; over 50 per cent of section area). Microvessel counts were performed in CD34-stained sections at × 400 magnification and were verified with computerized image analysis. The Kruskal–Wallis test was used to study the differences in microvessel count in different atherosclerotic plaque types.

Results

A total of 239 atherosclerotic lesions from 73 patients was available for analysis, of which 73 were early lesions, 74 were raised fibroatheromas and 92 were unstable atherosclerotic plaques. One hundred and fifty lesions were not haemorrhagic; 89 exhibited intraplaque haemorrhage, of which 28 involved less than 50 per cent of the plaque section area. In 61 lesions the haemorrhage area was over 50 per cent of the section area. There were higher microvessel counts in plaques containing more than 50 per cent haemorrhage (median 277 (range 43–467)) compared with those containing less than 50 per cent (172 (57–372)) and non-haemorrhagic plaques (81 (7–389)) (P < 0·0001). Higher microvessel counts were observed in unstable atherosclerotic lesions (median 252 (range 43–467)), compared with stable fibroatheromas (106 (14–302)) and early atherosclerotic lesions (55 (7–237)) (P < 0·0001).

Conclusion

There are strong associations between plaque vascularity and presence and size of haemorrhage within atherosclerotic lesions, as well as features of plaque instability. This finding highlights the likely significance of these new blood vessels in the development of plaque instability and subsequent risk of stroke.

Association between intraplaque haemorrhage in the carotid atherosclerotic lesion, the degree of internal carotid artery stenosis and timing of ischaemic neurological events

Background

Expansion of carotid atherosclerotic plaques as a result of intraplaque haemorrhage has been implicated in the development of ischaemic neurological events. The relationship between the quantity of haemorrhage in the dominant atherosclerotic lesion, the degree of internal carotid artery (ICA) stenosis and the chronology of patients' symptoms was examined.

Methods

Consecutive patients undergoing carotid endarterectomy were included. The nature and timing of symptoms were recorded. Aortic arch injection digital subtraction angiography was performed before operation. Carotid endarterectomy specimens were serially sectioned and examined histologically. The amount of intraplaque haemorrhage was measured with digital image analysis. The influence of timing of symptoms on the quantity of intraplaque haemorrhage was compared with Kaplan–Meier analysis. Correlation between degree of ICA stenosis and quantity of intraplaque haemorrhage was assessed by means of regression analysis.

Results

Seventy-four patients (20 asymptomatic, 54 symptomatic) were included. The median latency of symptoms was 28 (1–600) days. Intraplaque haemorrhage was common: 54 (73 per cent) of 74 patients. Mean(s.e.m.) cumulative symptom-free survival before operation for patients with no intraplaque haemorrhage was 0·71(0·11), compared with 0·58(0·11) in those exhibiting haemorrhage in less than 50 per cent of the plaque area, and 0·20(0·07) in lesions with over 50 per cent (P = 0·002). A close correlation was observed between the degree of ICA stenosis and haemorrhagic content of the dominant atherosclerotic lesion (r2 = 0·433, P < 0·001).

Conclusion

These results confirm the association between intraplaque haemorrhage and the degree of ICA stenosis. They further demonstrate an association between the size of haemorrhage and timing of neurological events, suggesting a causative role for intraplaque haemorrhage in the development of ischaemic neurological events.

Association between plaque instability, angiogenesis and symptomatic carotid occlusive disease

BACKGROUND

Angiogenesis is a recognized feature of the atherosclerotic process and has been described in the context of unstable coronary atherosclerotic lesions. The aim of this study was to assess the association between angiogenesis in atherosclerotic carotid plaques and microscopic features of plaque instability, in particular intraplaque haemorrhage.

METHODS

Consecutive patients undergoing carotid endarterectomy were included. Endarterectomy specimens were divided into their constituent atherosclerotic lesions. Histological sections were prepared and stained with haematoxylin and eosin, and immunohistochemically with an endothelial cell marker (CD34). The quantity of intraplaque haemorrhage was measured in transverse histological sections using computerized image analysis. Microvessel counts were performed in CD34-stained sections and were verified through computerized image analysis.

RESULTS

Some 239 atherosclerotic lesions from 73 patients were available for analysis; 73 were early lesions, 74 were raised fibroatheromas and 92 were unstable atherosclerotic plaques. One hundred and fifty lesions were not haemorrhagic; 89 exhibited intraplaque haemorrhage, of which 28 involved less than 50 per cent of the plaque sectional area. There were higher microvessel counts in plaques containing over 50 per cent haemorrhage (P < 0.0001), unstable atherosclerotic lesions (P < 0.0001) and atherosclerotic lesions obtained from symptomatic patients (P < 0.001).

CONCLUSION

There are strong associations between plaque vascularity, quantity of intraplaque haemorrhage and presence of symptomatic carotid occlusive disease.

Nutritional, respiratory, and psychological effects of recombinant human growth hormone in patients undergoing abdominal aortic aneurysm repair

BACKGROUND

Recombinant human growth hormone (rhGH) has been shown to have powerful anabolic effects and to reduce or even prevent nitrogen catabolism in stressed patients. The effects of rhGH on functional parameters are less clearly defined. The aim of this study was to assess the effects of perioperative rhGH on nutritional markers, skeletal muscle function, and psychological well-being in patients undergoing infrarenal, abdominal aortic aneurysm repair.

METHODS

Thirty-three patients undergoing elective infrarenal abdominal aortic aneurysm repair were randomized to one of three groups: (1) control (n = 12): placebo for 6 days before and after surgery; (2) preop + postop (n = 10): rhGH (Genotropin; Pharmacia Ltd, Uppsala, Sweden) 0.3 IU/kg/d for 6 days before and after surgery; and (3) postop (n = 11): placebo for 6 days before and rhGH 0.3 IU/kg/d for 6 days after surgery. Patients were assessed on days -7 and -1 before surgery and days 7, 14, and 60 after surgery.

RESULTS

Administration of rhGH resulted in increased insulin-like growth factor 1 levels, the increase being significantly more marked in the group given rhGH preoperatively. Preoperative and postoperative rhGH reduced the postoperative decrease in both serum transferrin and grip strength at day 7 by 30% and 70%, respectively. Postoperative respiratory function and arterial oxygenation also were improved, with significant differences in arterial oxygenation between rhGH-treated and untreated groups. No difference in mood was seen between groups after surgery, nor was there any difference between subjective assessment of fatigue scores between groups.

CONCLUSIONS

This pilot study indicates that rhGH administered preoperatively has beneficial effects on skeletal muscle and respiratory function and may be more useful than postoperative rhGH administration alone.

The effects of recombinant human growth hormone on cardiopulmonary function in elective abdominal aortic aneurysm repair

OBJECTIVES

Cardiorespiratory complications are the predominant source of morbidity in patients undergoing major surgery. Recombinant human growth hormone (rhGH) has previously been shown to be effective in improving respiratory and cardiac function in compromised patients.

DESIGN

The aim of this study was to assess the effects of perioperative rhGH on cardiac function in 33 patients undergoing elective infrarenal abdominal aortic aneurysm repair.

METHODS

Patients were randomised to one of three groups: placebo for 6 days before and after surgery (control, n = 12); genotropin (GH) 0.3 units/kg/day for 6 days before and after surgery (pre and postop GH, n = 10) and placebo for 6 days before and GH (0.3 units/kg/day) for 6 days after surgery (postop EH, n = 11). Patients were assessed on days 7 and 1 before and days 7, 14 and 50 after operation. Intraoperative cardiac index (CI) was measured after induction of anaesthesia, before and after aortic cross-clamping, after aortic unclamping and at the end of surgery.

RESULTS

Pretreatment with GH resulted in a significantly higher heart rate during surgery and was associated with a trend towards higher cardiac index (CI) (p < 0.067) at all stages of surgery. Mean arterial blood pressure at the stage of aortic unclamping was significantly higher in patients treated with GH preoperatively.

CONCLUSIONS

Larger studies are required to evaluate the beneficial effects of GH in aortic surgery. However, data from this pilot study suggests that perioperative GH administration may result in improved cardiac performance during aortic surgery.

Recurrent varicose veins

Recurrence of varicose veins after treatment has been reported as being between 7% and 65%. During the five month period from August to December 1993, 400 operations on 265 patients were performed for varicose vein disease. Of these, 53 patients had presented with recurrent vein disease in 72 limbs (18%). All patients underwent Duplex scanning of their deep and superficial systems and sites of venous incompetence were identified. The sapheno-femoral junction (SFJ) was found to be incompetent in 52 limbs, of which 31 had previously undergone flush ligation. Sapheno-popliteal junction (SPJ) was incompetent in 33 limbs, while the long saphenous vein (LSV) was found to be incompetent in 67 cases. There were no major complications in this group. Minor complications occurred in 10 cases (14%), mainly in the form of thigh paraesthesia. The more common causes of recurrent disease have been identified and therefore, it should be possible to reduce its incidence. Duplex scanning is essential for any unit dealing with recurrence.

Recurrent laryngeal nerve dysfunction following carotid endarterectomy

Recurrent laryngeal nerve dysfunction is a significant complication of carotid endarterectomy and vocal cord paralysis is a major source of morbidity. This study prospectively assessed patients undergoing carotid endarterectomy to determine the nature and frequency of vocal cord damage and attempt to identify avoidable factors. Fifty consecutive patients undergoing carotid endarterectomy for symptomatic disease were studied. A standardized surgical technique was used emphasizing identification of the vagus nerve and minimal disturbance of the surrounding tissues. All patients underwent pre-operative and post-operative (day 2) indirect laryngoscopy and videostroboscopy. Pre-operative assessment found asymptomatic compensated vocal cord paralysis in one patient who had previously had a stroke. Post-operative laryngoscopy revealed asymptomatic impaired vocal cord mobility in three patients (6%) all of whom recovered completely. In addition six patients (12%) developed post-operative hoarseness of whom five have fully recovered. The remaining patient (2%) developed vocal cord paralysis which is permanent to date. This prospective study demonstrates that recurrent laryngeal nerve dysfunction is a common but often transient complication of carotid endarterectomy. The incidence of vocal cord paralysis in this group was less than many of the reported series. This could be due to the technique of minimal dissection which may prevent disturbance of the vagal segmental blood supply. Pre-operative vocal cord assessment is essential in all patients undergoing carotid endarterectomy.

Plasma factors augment neutrophil and endothelial cell activation during aortic surgery

Lung injury following reperfusion results from endothelial damage caused by release of cytotoxic products by activated neutrophils (PMN) in the pulmonary microvasculature. This process is facilitated by the release of pro-inflammatory cytokines and arachidonic metabolites following the outset of reperfusion. This study aimed to evaluate the effect of plasma obtained before and after revascularisation on neutrophil and endothelial cell activation. Plasma (IR-plasma) was obtained from venous blood samples taken before and during aortic cross-clamping, and 5, 40 and 60 min following clamp removal in seven patients undergoing elective infrarenal aortic aneurysm resection. PMN from healthy volunteers (n = 5) were incubated with these plasma samples or with fMLP (N-formylmethionyl-leucyl-phenylalanine) as positive control for 30 min and assessed flow-cytometrically for CD11b expression. Human endothelial cells (ECV-304) were incubated with IR plasma for 2, 4 and 6 h or with tumour necrosis factor (TNF) (20 ng/ml) as positive control and assessed for ICAM-1 expression. Incubation with IR plasma resulted in a significant increase from pre-clamp in PMN CD11b expression. A similar trend was seen in endothelial cell ICAM-1 expression following 2 h incubation. These results indicate that reperfusion-induced endothelial dysfunction may be mediated by plasma factors released upon revascularisation which facilitate neutrophil-endothelial interaction through up-regulation of adhesion receptor expression.

Differential effects of lower limb revascularisation on organ injury and the role of the amino acid taurine

Lower torso revascularisation following ischaemia results in a systemic inflammatory response. Endothelial barrier function is disrupted by neutrophil-derived proteases and oxidants. Taurine, an amino acid found in large quantities in neutrophils, is a powerful endogeneous anti-oxidant. The aims of this study were to investigate the systemic effects of reperfusion following lower limb revascularisation and to evaluate the role of taurine administration in preventing this injury. A rat model of aortic occlusion (30 min) followed by 2 h of reperfusion was used. Animals were randomised to one of three groups (n = 10 per group): control; ischaemia reperfusion untreated (IR) and taurine-treated. Taurine (4% solution) was administrated orally for 48 h prior to the experiment. Neutrophil infiltration and microvascular permeability were assessed by measuring tissue myeloperoxidase activity and wet/dry weights respectively in lung, liver, kidney, and in cardiac and skeletal muscle. Statistical analysis was by means of analysis of variance (ANOVA). Reperfusion resulted in pulmonary and renal microvascular injury as assessed by organ oedema. Hepatic tissue, skeletal and cardiac muscle were unaffected by lower limb revascularisation. Taurine was effective in preventing neutrophil-mediated pulmonary but not renal microvascular injury. These data suggest that, whilst reperfusion-induced pulmonary injury is predominantly neutrophil-mediated, agents other than neutrophil-derived oxidative metabolites, capable of independently causing organ injury through direct endothelial damage, are produced during reperfusion.

Skin closure and the incidence of groin wound infection: a prospective study

Groin wound infection is a dreaded complication of vascular surgery and may jeopardize an underlying graft. A variety of skin closures have been used and the object of this study was to prospectively determine the relationship between skin closure and wound infection. One hundred fourteen consecutive patients (70 men and 44 women) undergoing bypass surgery with a groin incision (n = 173) were randomly assigned to skin closure with subcuticular Maxon, interrupted nylon, continuous nylon, or clips following a standard two-layer closure of subcutaneous tissue. Fourteen (12%) patients had diabetes and 50 (44%) had digital ulceration and gangrene. Aortofemoral bypass was performed in 25% of the patients and infrainguinal bypass in the remaining 75%. Perioperative wound cultures were obtained before closure. Wounds were inspected and cultures repeated on postoperative days 3, 5, 7, 10, and 14. Infection was defined as a positive culture. Groin wound infection occurred in 3% of the population and graft infection in 0.6%. The type of suture did not influence the incidence of infection. This study failed to demonstrate a significant difference in the incidence of wound infection with the use of different suture materials. We conclude that suture material should be selected on the basis of surgeon preference and costs.

Effects of hypothermia on the function, membrane integrity, and cytoskeletal structure of hepatocytes

To increase the storage time of livers for transplantation, a better understanding of hypothermia-induced hepatocyte damage is necessary. To this end, we have characterized the effects of hypothermia on long-term function and cytoskeletal organization of hepatocytes cultured in the collagen sandwich configuration, which maintains the expression of liver-specific functions for several weeks. In these studies, cultured hepatocytes (maintained at 37 degrees C for 7 days) were exposed to 4 degrees C in Leibovitz-15 (L15), University of Wisconsin (UW) solution, or L15 supplemented with 2.5 g% polyethylene glycol (PEG) for various time periods followed by a return to normothermia. When L15 medium was used, the long-term albumin secretion rate of cultured hepatocytes was decreased by 50% after 4 h, and by 95% after 24 h of exposure to 4 degrees C. Amorphous precipitates of F-actin and fragmented short microtubules were also observed after 4 and 12 h of hypothermia, respectively. Similar results were obtained when hepatocytes were stored in UW solution. However, in L15 supplemented with PEG, no significant reduction in long-term albumin secretion rates and intact actin and microtubule morphology was observed even after 24 h of exposure to 4 degrees C. The membrane integrity and long-term albumin secretion of hepatocytes stored in the presence of PEG were decreased to approximately 50% only after 48 h of exposure to 4 degrees C. Thus, PEG may be a useful additive in preservation solutions for hepatocytes in hepatocyte-based liver support systems and for intact tissue as well.

Renal haemodynamics and prostaglandin synthesis in partial unilateral ureteric obstruction

Haemodynamic changes in partial unilateral ureteric obstruction (PUUO) may be related to altered prostaglandin synthesis. In 12 dogs the left ureter was partially obstructed for 5 weeks. In six dogs the ureter was reimplanted into the bladder and to investigate the effect of this procedure on the contralateral side the other six animals underwent ipsilateral nephroureterectomy. Renal blood flow (RBF) was measured by the distribution of radiolabelled microspheres. Changes in urinary prostaglandin (PG) concentrations were validated by renin activity using angiotensin I. Reduced left RBF during obstruction was associated with increased thromboxane A2 synthesis (P < 0.01). Increased RBF to the non-obstructed side was associated with elevated PGE2 formation (P < 0.05). Elevated angiotensin I levels (P < 0.01) corresponded to maximal increases in PG synthesis. Reimplantation of the obstructed kidney did not exert a direct effect on contralateral RBF or PG concentration. Haemodynamic changes in PUUO in vivo are associated with alterations in renal PGs.

The comparison of type of incision for transperitoneal abdominal aortic surgery based on postoperative respiratory complications and morbidity

Equal access to the abdominal aorta can be attained through midline and transverse abdominal incisions. The surgical literature suggests that transverse incisions cause less postoperative pain and morbidity. Fifty patients (10 females and 40 males, mean age 67 years) undergoing abdominal aortic surgery were randomised to a midline (n = 25) or transverse (n = 25) incision. All patients were evaluated preoperatively and postoperatively for seven days. Changes in pulmonary function (FVC and FEV1), time to open and close the incision, analgesia used (morphine mg/kg/h), clinical or X-ray evidence of chest infection, and the duration of ICU stay were recorded. In the transverse group there was a reduction in the incidence of chest complications (20% vs. 28%, p = ns) and these incisions took longer to open (13.9 +/- 4.6 vs. 9.9 +/- 5.1, p < 0.05), but overall there was no significant difference between any other parameter in the two groups. Our results show no statistically significant difference in morbidity or analgesia consumption following transverse or midline abdominal incisions and we conclude that the type of incision used can be left to the surgeon's preference.

Is antibiotic penetration compromised in the ischaemic tissues of patients undergoing amputation?

Antibiotic prophylaxis is indicated for patients undergoing amputation for severe ischaemia or gangrene. However, the adequacy of tissue levels of antibiotics in ischaemic tissue is not known. In this study the serum and tissue antibiotic levels were measured after intravenous administration of metronidazole (15 mg/kg body weight) and cephradine (20 mg/kg body weight). In 11 patients, venous samples were taken at time 0 (induction of anaesthesia) 10, 30 and 60 min. Samples of 2 g each of fat and muscle were collected from the amputation site and three distal sites. Metronidazole and cephradine levels were measured and the degree of limb ischaemia estimated preoperatively by an isotope limb blood flow method. Our results indicate that both metronidazole and cephradine penetrate ischaemic tissues to levels equivalent of a Mean Inhibitory Concentration (MIC) 50 for most organisms encountered in vascular surgery, and that the degree of ischaemia does not alter this.

Effect of preclotting on the porosity and thrombogenicity of knitted Dacron grafts

The effects of single- and four-stage preclotting methods on graft porosity and thrombogenicity were compared in two types of Dacron prosthesis. The single-stage method significantly reduced leakage of blood (P less than 0.001), but did not seal the grafts. The four-stage method rendered the grafts impermeable at the second step. Thrombogenicity was compared by perfusing preclotted grafts with fresh heparinized blood (containing 111In-labelled platelets) in an artificial circulation. Platelet deposition and consumption were significantly less in the four-stage method whilst platelet function remained unchanged during perfusion. We conclude that the four-stage technique is superior to standard preclotting methods by rendering knitted Dacron grafts impermeable and hypothrombogenic.

Persistent Müllerian duct syndrome. Review and report of 3 cases

Three cases of persistent Müllerian duct syndrome are reported. All were phenotypically and karyotypically male but with persistent duct remnants. Problems encountered in management and surgery are discussed.

Urinary Tract Undiversion

Nine children underwent urinary diversion for lower urinary tract obstruction and were followed for periods of 2.5 to 15 years (median 10 years). Eight had cutaneous ureterostomies and the ninth had an ileal conduit. Undiversion was performed because of the return of normal function, the possibility of renal transplantation and ileal conduit stomal obstruction. The patients have been followed for periods ranging from 6 months to 9 years (median 2.5 years) after undiversion. To date, eight have moderate to good renal function. The remaining child has progressive renal failure. Eight are continent and one has mild stress incontinence.