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.

Can cytology accurately predict benign follicular nodules?

BACKGROUND: The reliability of fine-needle aspiration (FNA) biopsy in differentiating benign from malignant follicular lesions of the thyroid has been the subject of renewed debate recently. Although surgical excision has been recommended for most follicular lesions identified by cytology, this approach may not be necessary in all cases. The goal of this study was to determine whether FNA could be used as a diagnostic tool to safely identify patients with follicular thyroid nodules who do not require immediate surgical intervention. METHODS: A retrospective review was performed on a sample of 24 patients diagnosed with either follicular adenoma or follicular carcinoma after surgical excision of a thyroid nodule. The initial FNA biopsies were independently reviewed by two experienced cytopathologists in a blinded fashion and subsequently compared with final histologic diagnoses. RESULTS: For pathologist A, overall accuracy was 58%. The positive predictive value (PPV) of a benign diagnosis was 82%; PPV of a malignant diagnosis was 38%. For pathologist B, overall accuracy was 63%. The PPV of a benign diagnosis was 83%; PPV of a malignant diagnosis was 42%. CONCLUSIONS: This study suggests that in follicular lesions of the thyroid, a benign FNA biopsy report from an experienced cytopathologist has a high positive predictive value. The predictive value may not, however, be high enough to preclude surgery; other factors may need to be considered before recommending a nonoperative approach.

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.