C 0 R R E S PO N D E N C E 137

Indeed, in one elderly patient arm swelling and pain developed within 48 h of elbow fistula construction and was of such severity that emergency fistula ligation was required for symptomatic relief. In 13 of our patients obstructing lesions were identified by venography in either the subclavian vein or more proximal veins, 1 1 of which underwent endovenom battoon ditatation. AMough this procedure achieved the prolonged function of six fistulas, in the remaining patients access was lost due to persistent or recurrent arm swelling.

Patients for whom the formation of an elbow fistula is appro- priate usually have a history of previously failed vascular access. Often there have been multiple subclavian vein punctures, and if these have been ipsilateral to the intended fistula we now perform venography as a preliminary investigation '. If stenoses are present, preoperative balloon dilatation may still permit use of the intended site. However, if dilatation is not possible or fails, we seek improved conditions for AVF construction in the contralateral arm.

A. Ready A. D. Barnes

G. Lipkin Queen Elizabeth Medical Centre Edgbaston Birmingham B15 2TH UK

Surratt R,,Picus D, Hicks M et al. The importance of pre- operative evaluation of the subclavian vein in dialysis access planning. AJR A m JRoentgenol1991; 156: 623-5. Kahn D, Pontin AR, Jacobson JE et al. Arteriovenous fistula in the presence of subclavian vein thrombosis: a serious complica- tion. BrJSutg 1990; 77: 682. McNally PG, Brown CB, Moorhead PJ, Raferty AT. Unmasking of subclavian vein obstruction following creation of arterio- venous fistulae for haemodialysis. A problem following line dialysis. Nephrol Dial Transplant 1987; 1: 258-60.

Authors' reply

Sir We agree with Mr Ready and colleagues that our paper on elbow arteriovenous fistulas ( AVFs) contains little information on arm oedema. Actually, the first draft provided more data, but these were deleted to meet the need to shorten the manuscript. Ready and colleagues pertinently stress the need for a normal venous outflow in upper-limb AVFs. We are well aware that marked stenosis or even thrombosis of the subclavian vein may be revealed only after creation of vascular access in patients who have undergone subclavian vein catheterization. In a series of 42 asymptomatic patients we studied 10 years ago, phlebography performed a mean(s.d.) of 25.7(0.9) months after removal of subclavian catheters demonstrated 19 per cent complete occlusion or severe stenosis of the subclavian vein I . However, the rate of venous complications of temporary haemodialysis access can be dramatically reduced by using Silastic (Dow Corning, Midland, Michigan, USA) catheters placed in the internal jugular ~ e i n ~ , ~ .

In patients who have had subclavian vein punctures, we use the contralateral arm to create an AVF. If for some reason this is not possible, phlebography is performed. When the subclavian vein is occluded and the innominate vein is patent, an AVF can still be constructed in the upper arm by inserting an autologous saphenous vein graft between the brachial artery and the jugular vein. This technique was successfully used in two patients and allowed prolonged haemodialysis treatment. We prefer this type of AVF to thigh fistulas, which have a much higher incidence of pseudo- aneurysm4.

Finally, in two patients with a brachiocephalic anastomosis, who presented with huge oedema of the upper Iimb due to narrow stenosis of the subclavian vein resisting endoluminal dilatation, we were able to salvage the fistula by implanting a bypass graft between

the dilated cephalic vein and the internal jugular vein. Oedema subsided quickly and the fistula was again punctured easily.

J. Elcheroth L. De Pauw P. Kinnaert

Hbpital Erasme Route de Lennik 808 8-1070 Brussels Belgium

1 Vanherweghem JL, Yassine T, Goldman M et al. Subclavian vein thrombosis: a frequent complication of subclavian vein cannula- tion for hemodialysis. CIin Nephroll986; 26: 235-8.

2 Canaud B, Beraud JJ, Joyeux H, Mion C. Internal jugular vein cannulation using 2 Silastic catheters. A new, simple and safe long-term vascular access for extracorporeal treatment. Nephron

3 Cappello M, De Pauw L, Bastin G et al. Central venous access for haemodialysis using the Hickman catheter Nephrol Dial Transplant 1989; 4: 988-92.

4 Kinnaert P, Vereerstraeten P, Toussaint C, Van Geertruyden J. Saphenous vein loop fistula in the thigh for maintenance hemo- dialysis WorldJSurg 1979; 3: 95-8.

1986; 43: 133-8.

Transient femoral nerve palsy complicating preoperative ilioinguinal nerve blockade for inguinal herniorrhaph y

Sir I read with interest the article by Mr Rosario and colleagues (Br J Surg 1994; 81: 897) , having recently encountered an analogous problem in our unit. A 28-year-old man was submitted to right inguinal herniorrhaphy, during which an ilioinguinal nerve block was induced by percutaneous injection (by an experienced anaesthetist) of 20 ml 0.5 per cent bupivacaine adjacent to the anterior superior iliac spine. After operation the patient complained of diminished cutaneous sensation on the anterior aspect of the right thigh; clinical assessment confirmed the patient's impression of absent touch and pinprick sensation in a roughly triangular region of the upper anterolateral thigh, but there was no evidence of motor deficit nor of tendon reflex deficit in the quadriceps group. The patient was reassured and had completely recovered by the time of planned discharge the following morning.

As in other parts of the body, there is substantial overlap in the cutaneous sensory territories in the thigh of the femoral, lateral femoral cutaneous, subcostal and genitofemoral nerves, all these being branches of the lumbar plexus; it can therefore be difficult to be sure which nerve is affected on examination of cutaneous sensation. In the present case, the total absence of motor signs in the presence of complete anaesthesia of part of the upper thigh made it unlikely that a mixed motor/sensory peripheral nerve was involved, as the anaesthetic sensitivities of group A motor and sensory fibres are similar. We therefore excluded involvement of the femoral nerve itself, favouring instead inadvertent blockade of the lateral femoral cutaneous nerve (L2-L3) , of meralgia paraesthetica fame. The course of this nerve takes it about 1 cm medial to the anterior superior iliac spine en route to the upper thigh, and it seems rather more likely that extravasating local anaesthetic should involve this nerve than the others mentioned above. There does not appear to be a report of this in the literature thus far.

Western General Hospitals NHS Trust Edinburgh EH4 2XU UK

R. Price

British JournalofSurgery 1995,82,134-139

138 C O R R E S P O N D E N C E

Authors’ reply Simple method of tightening cutting setons Sir The lateral femoral cutaneous nerve follows an initial course similar to that of the femoral nerve. We agree that the cutaneous innervation of the thigh is inconstant and subject to considerable overlap, and it is feasible that in one of our patients (no. 3) a cutaneous branch of the lumbar plexus had been affected. However, the reason for reporting our observation was to point out that ‘blind ilioinguinal nerve blockade at the time of general anaesthesia for inguinal hernia repair may be associated with appreciable morbidity, particularly with regard to inpatient stay, and that the procedure carries no demonstrable advantages over perioperative ilioinguinal infiltration under direct vision.

D. J. Rosario P. Skinner

A. T. Raftery Northern General Hospital NHS Trust Herries Road Shefield S5 7AU UK

Ischaemic colitis induced by cocaine abuse

Sir Ischaemic colitis is a rare complication of cocaine We present a case of right colonic gangrene in a 25-year-old male cocaine abuser. The man complained of severe diffuse abdominal pain for 12 h. A history af cocaine and alcohol abuse was obtained from his family. The patient had inhaled an unknown amount of cocaine the night before admission, and he had also drunk a large amount of alcohol. Physical examination showed a confused agitated patient in acute abdominal distress. Blood pressure was 90160 mmHg, pulse irregular at 104 beats per min. Temperature was 395°C and there were no cardiac murmurs. The abdomen was distended and diffusely tender with guarding and rebound tender- ness. Bowel sounds were absent. During examination he suddenly experienced abdominal cramps followed by emission of liquid bloody stools.

Laboratory tests showed a haematocrit of 49 per cent, white cell count of 35 X loy/] with left shift, prothrombin time of 47 per cent and serum creatiniine level of 5.7pgldl. Plain abdominal radiography showed a non-specific bowel gas pattern. Abdominal computed tomography revealed an oedematous ascending colon and caecum, splenomegaly, and a normal liver and pancreas. At laparotomy the ascending colon and caecum were gangrenous, with a small free perforation. All other abdominal viscera were normal and there was full pulsation in the main visceral trunks and their branches. Right hemicolectomy with ileocolic anastomosis was followed by an uneventful recovery. The resection specimen showed ischaemic gangrene of the colon with no signs of embolism or atheroma. There was no evidence of chronic inflammatory bowel disease, granuloma or vasculitis.

We conclude that the patient had a focal ischaemic colitis caused by cocaine, a drug known to initiate vasoconstriction mediated by catecholamine release.

A. Sanjuanbenito Dehesa J. M. Fernandez Cebritin

Ramdn y Cajal Hospital Madrid Spain

1 Freudenberger DS, Cappell MS, Hutt DA. Intestinal infarction after intravenous cocaine administration. Ann Intern Med 1990;

2 Yang RD, Han M W , McCarthy JH. Ischemic colitis in a crack abuser. Dig DisSci 1991; 36: 238-40.

3 Fishel R, Harnamoto G, Barbul A, Jiji V, Efron G. Cocaine colitis. Is this a new syndrome? Dis Colon Rectum 1985; 26: 264-6.

Sir Messrs Seow-Choen and Leong’s method for avoiding repeated anaesthesia for setonage of anal fistula (Br J Surg 1994; 81: 12 14) is intriguing. However, a simpler and equally effective method is to pass several setons simultaneously at the initial procedure, but tying only one. The others are held together by separate threads but not tied. When the first seton becomes loose, it is discarded and another is readily freed and tied. This procedure can be repeated as many times as there are setons in situ.

United Bulawayo Hospitals PO Box 958 Bula way0 Zimbabwe

M. H. Cotton

Laparoscopic cholecystectomy for the left-handed surgeon

Sir Readers may be interested to learn of our experience in adapting laparoscopic cholecystectomy to accommodate the left-handed surgeon. In contrast to open operation, laparoscopic surgery is one area in which the left-handed surgeon is not disadvantaged by using right-handed instruments, although problems of access, exposure and cannula placement become more important. This is particularly true for gallbladder surgery, where good visualization of Calot’s triangle is vital and a satisfactory angle of approach to the cystic duct is required for clipping and cutting. We have tried a number of different configurations and found the following technique to be highly satisfactory.

The left-handed surgeon stands either between the legs or on the patient’s left-hand side, adhering to the principle that surgeon, gallbladder and television monitor should be in a straight line parallel to the direction of camera view. The camera is placed at the umbilicus and the fundus-retracting forceps in the right iliac fossa. A 5-mm cannula is placed in the mid-epigastrium for grasping Hartmann’s pouch and a 10-mm working port is established in the right subcostal region. Placement of the latter cannula is most critical: it must be close to the costal margin so that instruments enter the port almost vertically and are thus out of the line of camera view; it must also be placed more laterally than for the right-handed procedure to give a good angle of approach for dissecting Calot’s triangle, clipping the duct and using scissors. If the cannula is placed too far laterally, the surgeon has to bend over awkwardly and his or her left hand fouls with the side of the patient. It is worth establish- ing this port last of all, after visualizing the galIbladder and carefully establishing the ideal position.

The operation itself proceeds no differently from the standard right-handed technique, although dissection of the cystic duct and artery is done primarily from the right (posterior) aspect. Removal of the gallbladder may be via the right subcostal cannula but is best performed via the umbilicus after moving the camera to the subcostal port, particularly if the gallbladder is bulky.

This technique will allow the left-handed surgeon to perform the operation comfortably and ergonomically, a welcome change for the nondextrous, who are continually forced to adapt to a right-handed world.

L. Pouw B.Tisttoh

Echuca Regional Health Francis Street Echuca Victoria 3564 Australia

British Journal of Surgery 1995,82,134- 139