Active internal re-warming using a centrifugal pump and heat exchanger following haemorrhagic shock, surgical trauma and hypothermia in a porcine model.

BACKGROUND: The centrifugal vortex blood pump (CVBP) using heparin-bonded circuitry allows re-warming of hypothermic trauma patients without anticoagulation. Study objectives were to confirm efficacy, and to characterise the physiology of CVBP re-warming in a porcine model. METHODS: Sixteen pigs were randomised to conventional or CVBP re-warming. They were bled to a mean arterial pressure of 30 mmHg and cooled to 29 degrees C. A physiological analysis was recorded during resuscitation to normo-tension and re-warming back to 37 degrees C. RESULTS: CVBP animals re-warmed significantly faster: 85.0+16.4 min versus 217.4+49.3 min (p<0.0001). Activated clotting time was significantly elevated in both groups at 29 degrees C with a marked trend to normalise faster in CVBP pigs. The peak cardiac index (CI) was significantly lower (1.14+0.68 versus 4.83+1.50 L/(min m2), while the systemic vascular resistance (SVR) was significantly higher (4239.9+1173.0 versus 1472.6+451.2 dyn x S x m2/cm5) with CVBP (p<0.001). CONCLUSION: CVBP is simple and very effective at re-warming hypothermic animals and may also reverse coagulopathy more quickly. Physiological derangements of elevated SVR and diminished CI require further study to elaborate underlying aetiology, and define optimal re-warming strategies.

Utility of screening for blunt vascular neck injuries with computed tomographic angiography.

PURPOSE: To prospectively study the impact of implementing a computed tomographic angiography (CTA)-based screening protocol on the detected incidence and associated morbidity and mortality of blunt vascular neck injury (BVNI). METHODS: Consecutive blunt trauma patients admitted to a single tertiary trauma center and identified as at risk for BVNI underwent admission CTA using an eight-slice multi-detector computed tomography scanner. The detected incidence, morbidity, and mortality rates of BVNI were compared with those measured before CTA screening. A logistic regression model was also applied to further evaluate potential risk factors for BVNI. RESULTS: A total of 1,313 blunt trauma patients were evaluated. One hundred seventy screening CTAs were performed, of which 33 disclosed abnormalities. Twenty-three were evaluated angiographically, of which 15 were considered to have significant BVNIs, as were 4 of the 10 patients with abnormal CTAs and no angiogram. The incidence of angiographically proven BVNIs in our series was 1.1%. If four patients who were treated for BVNIs based on CTA alone are included, the incidence rises to 1.4%. This is significantly higher than the 0.17% incidence before screening (p < 0.001). In addition, the delayed stroke rate and injury-specific mortality fell significantly from 67% to 0% (p < 0.001) and 38% to 0% (p = 0.002), respectively. Overall mortality also fell significantly, from 38% to 10.5% (p = 0.049). Univariate logistic regression identified the presence of cervical spine injury as a significant predictor of BVNI (p < 0.001). CONCLUSION: CTA screening increases the detected incidence of BVNI 8-fold, with rates similar to angiographically based screening protocols. CTA screening significantly decreases BVNI-related morbidity and mortality in an efficient manner, underlying its utility in the early diagnosis of this injury.

T1a breast carcinoma and the role of axillary dissection.

HYPOTHESIS: Axillary dissection (AD) does not affect recurrence or survival in T1a breast cancer. DESIGN: Cohort study comparing patients who underwent AD and those who did not. SETTING: Provincial cancer agency. PATIENTS: Six hundred ninety-one women with pathologically diagnosed T1a tumors. MAIN OUTCOME MEASURES: Rates of axillary metastases stratified according to grade and lymphovascular and/or neural invasion, rates of relapse, and disease-specific survival. RESULTS: Grade 1, 2, and 3 tumors without lymphovascular and/or neural invasion had axillary nodal involvement rates of 0.7%, 7%, and 7.8% of patients, respectively; with lymphovascular and/or neural invasion, axillary nodes were involved in 9.1%, 39.3%, and 44.4%, respectively. No statistically significant differences were found between the cohorts in relapse rates (P =.70) or survival (P =.84). CONCLUSION: Higher tumor grade and lymphovascular and/or neural invasion increased the rate of nodal metastases in T1a tumors, but AD did not improve relapse rates or breast cancer-specific survival.

Endovascular repair of a ruptured renal artery aneurysm.

PURPOSE: To describe the percutaneous treatment of a ruptured renal artery aneurysm (RAA) using a stent-graft. CASE REPORT: An 86-year-old woman had sudden onset of right-sided back pain and a swollen left leg. Computed tomography disclosed a right retroperitoneal mass involving the kidney; the inferior vena cava was compressed, with thrombus in the left common iliac artery. There was a suggestion of RAA associated with contrast extravasation. Angiography confirmed a saccular aneurysm of the distal right main renal artery immediately proximal to the first segmental branch. A Jostent peripheral stent-graft was implanted with complete exclusion of the lesion. At 6-month follow-up, the patient remained asymptomatic, but there was a suggestion of in-stent restenosis, which is being followed closely. CONCLUSIONS: In elderly patients who are hemodynamically stable and have aneurysm anatomy that is suitable for stent-graft placement, the endovascular approach may allow rapid and definitive treatment of the hemorrhage.