{'fraction_non_alphanumeric': 0.01876675603217158, 'fraction_numerical': 0.00871313672922252, 'mean_word_length': 4.924603174603175, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Continuous intravenous morphine for pain relief after abdominal surgery.

We read with interest the article by Slater and Raftery (Annals, July 1988, vol 70, p243) evaluating PTFE loop graft patency, complications and patient survival. In addition to their experience we should like to include a further possible complication, brought to light in a recent case. A 36-year-old farmer had a PTFE loop graft inserted into the right groin 6 years previously for haemodialysis. Three years later a successful renal transplant was performed. Since then, over the last 3 years, he had been asymptomatic until jumping down from a tractor. The patient experienced pain and parathesiae of sudden onset in the right foot and calf. Examination revealed an acutely ischaemic leg, a normal femoral pulse, but none below on the affected side. An arteriogram showed a unilateral right common femoral artery occlusion compatible with an acute thrombotic episode. The loop graft was also thrombosed. At operation, his groin was explored and fresh thrombus was found occluding his common femoral artery, with old thrombus extruding from the PTFE loop graft into the lumen of that artery at the anastomotic site. After thrombectomy and removal of the loop graft he made an uneventful recovery. This experience might suggest that the thrombosed loop graft was at fault causing the acute ischaemic episode. A M CLARKE MB BS Senior House Officer M HORROCKS MS FRCS Consultant Surgeon Bristol Royal Infirmary Bristol