Objective: This study aims to examine the use of a radial artery graft for bypass of the maxillary artery (MA) to the supraclinoid internal carotid artery (ICA) in treating ICA occlusions.

Study design and setting: This method was carried out on five adult cadaver sides. The MA was reached 1–2 cm inferior to the crista infratemporalis, following a frontotemporal craniotomy and a zygomatic arch osteotomy. Extradurally 2–3 cm lateral to the foramen rotundum, a hole was drilled in the sphenoid bone with a 4 mm tipped drill. A radial artery graft was passed through the hole to the inside of the dura. Before giving the infraorbital artery branch, the MA was dissected from the surrounding tissue and transected. The proximal end of the graft was anastomosed end-to-end with the MA and the distal end of the graft end-to-side with the supraclinoid ICA.

Results: The mean calibre of the MA was 2.6 ± 0.3 mm. The mean calibre of the proximal end of the radial artery graft was 2.5 ± 0.25 mm and the distal end was 2.35 ± 0.2 mm. The mean length of the radial artery graft was 4.0 ± 0.5cm.

Conclusion: This study suggested that the cases with ICA occlusion, which require high blood flow, may be treated as an alternative to current bypass methods requiring long vein grafts.

Mobilisation of the latissimus dorsi muscle as a functional graft necessarily involves division of perforating arteries that enter the distal portion of the muscle, rendering it vulnerable to ischaemic damage when the muscle is stimulated electrically. Using a fluorescent microsphere technique we showed that the blood flow contributed by the thoracodorsal artery decreases in a proximal-to-distal direction, and that of the perforating arteries in a distal-to-proximal direction, but for neither does the flow decline to zero. This is consistent with earlier reports of anastomotic connections between the 2 arterial territories. We went on to use fluorescence microscopy to demonstrate the existence of these vascular anastomoses, the first such evidence obtained under physiological conditions of pressure and flow. In clinical applications, the existence of anastomotic connections offers the prospect of maintaining flow to the distal part of the grafted muscle without the delays inherent in neovascularisation procedures.

A comparison was made between the rate of passage of digesta through the digestive tract of pigs with an ileo-rectal anastomosis (IRA) or an Heal T-cannula according to the single marker dose method by using polyethylene glycol (PEG) as liquid marker, Cr2O3 as solid phase marker and Yb2O3-mordantedcell walls as fibre marker. The rate of passage was slightly faster with IRA than with cannulated pigs.

Water balance, electrolyte and acid-base status of a group of five South African Mutton Merino wethers given chopped lucerne hay ad libitum was determined before and after ileorectal anastomosis. In general, the sheep recovered rapidly from surgery, resuming, within 10 days, a level of dry matter intake only slightly less than pre-operative levels (1323 (s.e. 147) and 1419 (s.e. 196) g/day respectively, P > 0·05). A new water balance was established at about the same time, when sheep with an ileorectal anastomosis drank about 2500 ml/day more water, while losing about 2400 ml/day more water in the faeces and about 365 ml/day less water in the urine than did the control sheep. Most of the electrolyte and acid-base parameters tested were not significantly affected by the anastomosis but the concentrations of oxygen and potassium in the blood of sheep with an anastomosis were significantly lower (P < 0·001), while those of chloride (P < 0·001) and bicarbonate (P < 0·05) were significantly higher, than before surgery. These observations, together with normal blood pH values, suggest that bypassing the large intestine caused a compensated metabolic alkalosis.

Energy balance was determined on the five sheep with an ileorectal anastomosis as well as five control animals in an indirect, open-circuit calorimeter. Despite a significantly lower (P < 0·05) loss of nitrogen and energy via the urine (due to a lower output of urine) in sheep with an ileorectal anastomosis, total heat loss, whether absolute or relative to energy intake, did not differ from control values and therefore indicated that basal metabolic rate was not significantly affected.

From post-mortem examinations, anastomoses appear to have induced a marked atrophy of the bypassed caecum and colon, whilst the mass of the large intestine was significantly less than in control animals, despite the significant enlargement of the rectum. On the other hand, the small intestine appeared unaffected, either macroscopically or histologically.

The most significant physiological changes that occurred on bypassing the large intestine were related to loss of water reabsorbtion. However, good adaptation to the increased turn-over of water was evident, providing free access to water and a salt lick was allowed.