Is aortic occlusion advisable in the management of massive hemorrhage? Experimental study in dogs.

Occlusion of the thoracic aorta is meant to improve cerebral and cardiac perfusion in the moribund, exsanguinating trauma patient. Yet clinical and experimental experience shows no evident benefit from this critical maneuver, and hind limb paralysis (HLP) is a feared complication. Our study is intended to verify whether aortic occlusion can decrease further blood loss and therefore be useful during treatment of hemorrhagic shock. Four groups of 10 dogs were submitted to hemorrhagic shock and treated with blood (40 mL/kg) and saline (35 mL/kg). Group I was then submitted to intermittent intra-aortic occlusion (IIAO), Groups II and III to IIAO and to a second bleeding (rebleeding), and Group IV to rebleeding only, without IIAO. All dogs received volume replacement during this rebleeding phase and were kept alive for 8 days. Five dogs died and seven had HLP in the three groups submitted to IIAO. Death and HLP occurred even in the dogs of Group I, which were not submitted to a second bleeding. IIAO reduced blood loss from 139 mL/kg to 48 mL/kg. There were no complications or deaths among the 10 dogs in Group IV. Although efficient in reducing blood loss, IIAO was associated with a 16% mortality and 23% of HLP, whereas volume replacement alone was tolerated without complications or death. We conclude that IIAO is dangerous while treating severe hemorrhagic shock even after volume replacement and hemodynamic stabilization.

Blood supply to the human sternocleidomastoid muscle by the sternocleidomastoid branch of the occipital artery.

The contribution of the sternocleidomastoid branch of the occipital artery, superior arterial pedicle (SAP), to the irrigation of the sternocleidomastoid muscle (SCM) was evaluated in fresh human cadavers by injecting Neoprene-latex for minute dissection. From its insertion in the mastoid process of the temporal bone, the SCM was divided into six levels. The Neoprene-latex injected into the SAP reached the upper three levels in all SCMs studied, which corresponds to the middle part of the studied SCM. In 43.3% of the SCM, this branch reached level four and in 36.6%, it reached level five.

Variation of infrarenal aortic diameter: A necropsy study.

PURPOSE: To determine anatomicomorphological changes in the infrarenal portion of the abdominal aorta, we performed 645 dissections of the segment in corpses undergoing necropsy. METHODS: The aortas were removed from the corpses with a surgical technique; by means of a device that we designed, the external diameter of the artery was measured after luminal pressure was reestablished. This way, it was possible to avoid underestimation of the arterial diameter postmortem. The influence of age, sex, body size, arterial hypertension, chronic obstructive pulmonary disease, and coronary disease on the aortic diameter and the influence of different degrees of sclerosis on the infrarenal aorta wall were analyzed. Considering the diameters, aortas were regarded as "normal" when they did not present any ectasia, arteriomegaly, aneurysm, or hypoplasia. RESULTS: The sample involved 645 subjects whose ages ranged from 19 to 97 years (mean age, 55.8 years). Of the 645 subjects, 65.5% (423) were men, 34.5% (222) were women, 81% (523) were white, and 19% (122) were of another race. The diameters of arteries showing no anomalous dilatation (ectasis, arteriomegaly, or aneurysm) varied according to subject age, sex, body length, and the degree of atherosclerosis on the aorta wall (P <.01). Aortic diameters of those subjects with arterial hypertension, coronary disease, and chronic obstructive pulmonary disease were compared with the aortic diameters of control subjects, and significant differences were not shown (P >.05). Twenty-nine aneurysms were found (4.5% prevalence). Four were ruptured aneurysms, and all occurred in aortas with diameters larger than 5.0 cm. CONCLUSION: The infrarenal aortic diameter enlarges with aging, and this enlargement occurs earlier in men than in women. Those subjects who had a longer body length and advanced sclerosis on the aorta wall had larger aortic diameters. There was a high prevalence of infrarenal aneurysms (4.5%), with rupture found solely in aortas with diameters larger than 5.0 cm.