G. Douglas Tracy

Prospective Randomized Trial of Polytetrafluoroethylene and Dacron Aortic Prosthesis. I. Perioperative Results

Over a two year period 80 patients were entered into a prospective randomized trial comparing polytetrafluoroethylene (PTFE) and Dacron infrarenal aortic reconstructions. Fifty-four patients were treated for aneurysm (30 single tubed grafts; 24 bifurcation grafts), and 26 patients were treated for occlusive disease (26 bifurcation grafts). The groups were matched for age, sex and preoperative risk factors. Five patients died after operation (6.3%) including two from hemorrhage, but there were no significant differences in mortality and morbidity between the PTFE and Dacron groups. The volume of blood lost at operation (1930 +/- 1340 ml, all patients); the volume of blood transfused (2.98 +/- 2.43 units); the volume of crystalloids infused (3050 +/- 1390 ml); the intraoperative heparin dosage (67.9 +/- 20.5 mg); the clamp time (71.6 +/- 34.5 min); and the total operating time (228.1 +/- 78.3 min) also showed no significant differences between PTFE and Dacron. The ankle systolic pressure index rose more for PTFE (0.96 +/- 0.24) than for Dacron (0.82 +/- 0.20; P less than 0.002) at the time of discharge. This partially reflects a difference in the index between the groups before operation (PTFE 0.79 +/- 0.30; Dacron 0.72 +/- 0.32), but it may also indicate that PTFE is less thrombogenic than Dacron.

Duodenal Obstruction Following Abdominal Aortic Reconstruction

Four patients developed duodenal obstruction after 161 abdominal aortic reconstructions, an incidence (2.5%) rivaling that of graft infection and arterioenteric fistula. The diagnosis is easily confirmed by gastrointestinal contrast studies. Duodenal obstruction is usually caused by perigraft collagenous adhesions and is probably less likely to occur if the mobilized duodenum is not replaced directly over the aorta during resuture of the retroperitoneum. Undetected duodenal obstruction leads to rapid dehydration and electrolyte and caloric depletion.

Iatrogenic femoral aneurysms.

The article is a timely inclusion in this journal dealing with risk management, but some important issues arising from the article have not been addressed. Were all cases from one institution? If so, any risk management conference does not seem to have been effective. All eight cases were associated with fracture treatment at the upper end of the femur, where it is well known that overpenetration by drills or screws is the common cause. What can be done to guard against such a technical mishap? This is the province of sound orthopaedic training, which stresses the anatomical proximity of the large vessels, the hazards of dull drill bits, unthreaded guidewires and the role of visual checking with image intensifiers, etc. (Cumberland, pers. comm.). It should not be forgotten that knee joint replacements, where mechanical saws that pass through the posterior ligament of the joint, within a hairsbreadth of the popliteal vessels, are also the setting for occasional vascular disaster. Late diagnosis is stressed in the article, but no remedial strategy. The diagnosis of ‘iatrogenic pseudoaneurysm’, alternatively called pulsating haematoma, can be made, simply and non-invasively, with duplex ultrasound, whereas the expansile pulsation is often detected by gentle palpation. If there is venous as well as arterial injury, an A–V fistula will have a palpable thrill, with a loud murmur heard readily with a simple stethoscope. As in the illustrations, the haematoma is much larger than its pulsating cavity. Only the cavity is seen in the arteriogram, smaller than a golf ball, whereas the thigh swelling is larger than an orange. A duplex scan will show both the haematoma and the cavity. All these aneurysms were treated by open repair, which is often not necessary. Were they treated by the orthopaedic surgeons or vascular surgeons? Prudent risk management dictates that orthopaedic surgeons (hopefully) inexperienced in iatrogenic vascular injury should call in vascular surgeons without delay. Open operation can be bloody and difficult, especially with a fresh A–V fistula, as the surgeon tries to gain control of the involved arteries (and/or veins) before entering the haematoma, which can be large. It introduces the risk of microbial contamination, potentially disastrous for the arterial repair or the fracture. If the aneurysm is small, with a pin-hole opening, it might be cured by gentle compression with the duplex probe, holding the cavity empty for long enough to induce clotting.1 If unsuccessful, there is a variety of endovascular techniques, safer and simpler than open repair, such as ultrasound-guided thrombin injection,2 endovascular coil insertion3 and/or stent insertions,4 which might remove the need for majority of open reconstructions.