Body fat changes among antiretroviral-naive patients on PI- and NNRTI-based HAART in the Swiss HIV cohort study

BACKGROUND: Body fat changes are common in patients with HIV. For patients on protease inhibitor (PI)-based highly active antiretroviral therapy (HAART), these changes have been associated with increasing exposure to therapy in general and to stavudine in particular. Our objective is to show whether such associations are more or less likely for patients on non-nucleoside reverse transcriptase inhibitor (NNRTI)-based HAART. METHODS: We included all antiretroviral-naive patients in the Swiss HIV Cohort Study starting HAART after April 2000 who had had body weight, CD4 cell count and plasma HIV RNA measured between 6 months before and 3 months after starting HAART, and at least one assessment of body fat changes after starting HAART. At visits scheduled every 6 months, fat loss or fat gain is reported by agreement between patient and physician. We estimate the association between reported body fat changes and both time on therapy and time on stavudine, using conditional logistical regression. RESULTS: Body fat changes were reported for 85 (9%) out of 925 patients at their first assessment; a further 165 had only one assessment. Of the remaining 675 patients, body fat changes were reported for 156 patients at a rate of 13.2 changes per 100 patient-years. Body fat changes are more likely with increasing age [odds ratio (OR) 1.18 (1.00-1.38) per 10 years], with increasing BMI [OR 1.06 (1.01-1.11)] and in those with a lower baseline CD4 cell count [OR 0.91 (0.83-1.01) per 100 cells/microl]. There is only weak evidence that body fat changes are more likely with increasing time on HAART [OR 1.16 (0.93-1.46)]. After adjusting for time on HAART, fat loss is more likely with increasing stavudine use [OR 1.70 (1.34-2.15)]. There is no evidence of an association between reported fat changes and time on NNRTI therapy relative to PI therapy in those patients who used either one therapy or the other [OR 0.98 (0.56-1.63)]. CONCLUSION: Fat loss is more likely to be reported with increasing exposure to stavudine. We find no evidence of major differences between PI and NNRTI therapy in the risk of reported body fat changes.

[Manifestation and course of coronary heart disease in men and women--consequences for diagnosis and treatment]

Gender related issues in manifestation, diagnosis and treatment of coronary artery disease are important but still not well recognized. Women are more likely to present late after first symptoms of myocardial infarction. Myocardial infarction is more often unrecognized. In regard to complications after myocardial infarctions ventricular tachycardia and cardiac arrest are more frequent and women are also more likely to develop heart failure or cardiogenic shock. The reason for this is most probably the fact that women presenting with myocardial infarction are of older age and have a higher incidence of co-morbidities. Thrombolysis and coronary angioplasty are less often performed in women in the setting of myocardial infarction. However there is a clear trend toward improvement of this situation during the last years. The reopening rate of occluded coronary arteries with thrombolysis and with coronary angioplasty is similar in women compared to men. Perioperative risk with aorto-coronary bypass surgery is higher in women, which can not be fully explained by higher age and co-morbidities. However 10 years survival rate after aorto-coronary bypass-surgery is similar for men and women, although occlusion of venous grafts is seen more often in women. The benefit of structured cardiac rehabilitation after an acute event is similar for younger and older women and as good as in men. Positive effects of cardiac rehabilitation include increased physical performance, reduction of body fat, improvement of lipid-profiles and an improvement of the psychosocial situation and quality of life.

Links between body mass index, total body fat, cholesterol, high-density lipoprotein, and insulin sensitivity in patients with obesity related to depression, anger, and anxiety

OBJECTIVE: Define links between psychosocial parameters and metabolic variables in obese females before and after a low-calorie diet. METHOD: Nine female obese patients (age 36.1 +/- 7.1 years, body mass index [BMI] > 30 kg/m2) were investigated before and after a 6-week low-calorie diet accompanied by behavior therapy. Blood lipids, insulin sensitivity (Bergman protocol), fat distribution (by dual-energy X-ray absorptiometry [DEXA]), as well as psychological parameters such as depression, anger, anxiety, symptom load, and well-being, were assessed before and after the dieting period. RESULTS: The females lost 9.6 +/- 2.8 kg (p < .0001) of body weight, their BMI was reduced by 3.5 +/- 0.3 kg/m2 (p < .0001), and insulin sensitivity increased from 3.0 +/- 1.8 to 4.3 +/- 1.5 mg/kg (p = .05). Their abdominal fat content decreased from 22.3 +/- 5.5 to 18.9 +/- 4.5 kg (p < .0001). In parallel, psychological parameters such as irritability (p < .05) and cognitive control (p < .0001) increased, whereas feelings of hunger (p < .05), externality (p < .05), interpersonal sensitivity (p < .01), paranoid ideation (p < .05), psychoticism (p < .01), and global severity index (p < .01) decreased. Prospectively, differences in body fat (percent) were correlated to nervousness (p < .05). Waist-to-hip ratio (WHR) differences were significantly correlated to sociability (p < .05) and inversely to emotional instability (p < .05), whereas emotional instability was inversely correlated to differences in insulin sensitivity (p < .01). DISCUSSION: Weight reduction may lead to better somatic risk factor control. Women with more nervousness and better sociability at the beginning of a diet period may lose more weight than others.

Vascular adaptation of the internal thoracic artery graft early and late after bypass surgery

OBJECTIVE: Flow mismatch between the supplying artery and the myocardial perfusion region has been observed in patients with internal thoracic artery grafts. Thus coronary flow changes of arterial (internal thoracic artery grafts) and saphenous (saphenous vein grafts) bypass grafts were studied early and late after coronary artery bypass grafting. METHODS: Thirty patients undergoing elective bypass surgery (internal thoracic artery and saphenous vein grafts) were studied intraoperatively and (17 patients) 3 to 10 months postoperatively. Coronary flow was measured intraoperatively with the transit-time Doppler scanning technique. Postoperatively, flow velocity and coronary flow reserve were determined with the Doppler flow wire technique. Quantitative angiographic analysis was used to determine vessel size for calculation of absolute flow. RESULTS: Intraoperatively, internal thoracic artery graft flow was significantly lower than saphenous vein graft flow (31 +/- 8 vs 58 +/- 29 mL/min, P < .01). Postoperatively, internal thoracic artery graft flow increased significantly to 42 +/- 24 mL/min at 3 months and to 56 +/- 30 mL/min (P < .02 vs intraoperative value) at 10 months, respectively. However, saphenous vein graft flow remained unchanged over time (58 +/- 29 to 50 +/- 27 mL/min at 3 months and 46 +/- 27 mL/min at 10 months). Coronary flow reserve was abnormally low intraoperatively in the internal thoracic artery (1.3 +/- 0.3) and saphenous vein (1.6 +/- 0.5) grafts but increased significantly to normal values in both types of graft at follow-up. CONCLUSIONS: Bypass flow of the internal thoracic artery graft is significantly reduced intraoperatively when compared with that of the saphenous vein graft. However, 3 and 10 months after the operation, flow of the internal thoracic artery graft increases significantly and is similar to saphenous vein graft flow. This finding can be explained by an early flow mismatch of the native internal thoracic artery in the presence of a large perfusion territory. During follow-up, there is vascular remodeling of the internal thoracic artery, probably because of endothelium-mediated mechanisms.

Off-pump extraanatomic aortic bypass for the treatment of complex aortic coarctation and hypoplastic aortic arch

BACKGROUND: Despite advances in surgical and interventional techniques, the optimal surgical treatment of severe aortic (re) coarctation and hypoplastic aortic arch is still controversial. Anatomic repair may require extensive dissection, cardiopulmonary bypass, and deep hypothermic circulatory arrest with their inherent risks. The aim of this study was to analyze the outcome of off-pump extraanatomic aortic bypass as a surgical alternative to local repair. METHODS: From February 2000 to December 2005, ten consecutive patients (median age 20 years; range, 11 to 38 years) with severe aortic (re) coarctation (n = 4) and (or) hypoplastic aortic arch (n = 7) underwent off-pump extraanatomic aortic bypass through median sternotomy. All but three patients had undergone previous surgery for coarctation and angioplasty or stenting. Three patients underwent concomitant replacement of the ascending aorta because of an aneurysm using cardiopulmonary bypass. RESULTS: Postoperative hospital course was uneventful in all patients. There was no perioperative mortality or significant morbidity. During a mean follow-up of 48 +/- 22 months no patient required additional procedures. All patients were free of symptoms; no patient showed signs of heart failure after follow-up. At last follow-up, no patient presented with claudication, nor any patient experienced orthostatic problems due to a steal phenomenon. During follow-up, hypertension resolved in all patients with residual mild hypertension in two patients. CONCLUSIONS: Off-pump extraanatomic aortic bypass is an attractive treatment option for complex aortic (re) coarctation and hypoplastic aortic arch. Perioperative risks are minimized, hypertension is influenced favorably, and midterm survival is event-free.

Automated, compliant, high-flow common carotid to middle cerebral artery bypass

The authors describe the use of the Cardica C-Port xA Distal Anastomosis System to perform an automated, high-flow extracranial-intracranial bypass. The C-Port system has been developed and tested in coronary artery bypass surgery for rapid distal coronary artery anastomoses. Air-powered, it performs an automated end-to-side anastomosis within seconds by nearly simultaneously making an arteriotomy and inserting 13 microclips into the graft and recipient vessel. Intracranial use of the device was first simulated in a cadaver prepared for microsurgical anatomical dissection. The authors used this system in a 43-year-old man who sustained a subarachnoid hemorrhage after being assaulted and was found to have a traumatic pseudoaneurysm of the proximal intracranial internal carotid artery. The aneurysm appeared to be enlarging on serial imaging studies and it was anticipated that a bypass would probably be needed to treat the lesion. An end-to-side bypass was performed with the C-Port system using a saphenous vein conduit extending from the common carotid artery to the middle cerebral artery. The bypass was demonstrated to be patent on intraoperative and postoperative arteriography. The patient had a temporary hyperperfusion syndrome and subsequently made a good neurological recovery. The C-Port system facilitates the performance of a high-flow extracranial-intracranial bypass with short periods of temporary arterial occlusion. Because of the size and configuration of the device, its use is not feasible in all anatomical situations that require a high-flow bypass; however it is a useful addition to the armamentarium of the neurovascular surgeon.

The effect of pulsed jet lavage in vertebroplasty on injection forces of polymethylmethacrylate bone cement, material distribution, and potential fat embolism: a cadaver study

STUDY DESIGN: In vitro testing of vertebroplasty techniques including pulsed jet-lavage for fat and marrow removal in human cadaveric lumbar and thoracic vertebrae. OBJECTIVE: To develop jet-lavage techniques for vertebroplasty and investigate their effect on cement distribution, injection forces, and fat embolism. SUMMARY OF BACKGROUND DATA: The main complications of cement vertebroplasty are cement leakage and pulmonary fat embolism, which can have fatal consequences and are difficult to prevent reliably by current vertebroplasty techniques. METHODS: Twenty-four vertebrae (Th8-L04) from 5 osteoporotic cadaver spines were grouped in triplets depending on bone mineral density (BMD). Before polymethylmethacrylate (PMMA) vertebroplasty, a pulsatile jet-lavage for removal of intertrabecular fat and bone marrow was performed in 2 groups with 8 specimens each, performing radial and axial irrigation from the biopsy needles. One hundred mL of Ringer solution were injected through 1 pedicle and regained by low vacuum via the contralateral pedicle. Eight control vertebrae were not irrigated. All specimens underwent standardized PMMA cement augmentation injecting 20% of the vertebral volume. Injection forces, cement distribution, and extravasations were quantified. RESULTS: All irrigation solution could be retrieved with the vacuum applied. A Kruskal-Wallis test revealed significantly higher injection forces of the control group as compared with the irrigated groups (P = 0.021). Dilatation of the syringe at forces above 300 N occurred in 75% of the untreated compared with 12.5% of the lavaged specimens. CT distribution analysis showed more homogenous cement distribution of the cement and significantly less extravasation in the irrigated specimens. CONCLUSION: The developed lavage technique for vertebroplasty showed to be feasible and reproducible. The reduction of injection forces would allow the use of more viscous PMMA cement lowering the risk for cement embolization and results in a safer procedure. The wash-out of bone marrow and the possible reduction of pulmonary fat embolism have to be verified with in vivo models.

Fat implant is superior to muscle implant in vestibular schwannoma surgery for the prevention of cerebrospinal fluid fistulae

OBJECTIVE: Meticulous sealing of opened air cells in the petrous bone is necessary for the prevention of cerebrospinal fluid (CSF) fistulae after vestibular schwannoma surgery. We performed a retrospective analysis to determine whether muscle or fat tissue is superior for this purpose. METHODS: Between January 2001 and December 2006, 420 patients underwent retrosigmoidal microsurgical removal by a standardized procedure. The opened air cells at the inner auditory canal and the mastoid bone were sealed with muscle in 283 patients and with fat tissue in 137 patients. Analysis was performed regarding the incidence of postoperative CSF fistulae and correlation with the patient's sex and tumor grade. RESULTS: The rate of postoperative CSF leak after application of fat tissue was lower (2.2%) than after use of muscle (5.7%). Women had less postoperative CSF leakage (3.4%) than men (5.6%). There was an inverse correlation with tumor grade. Patients with smaller tumors seemed to have a higher rate of CSF leakage than those with large tumors without hydrocephalus. Only large tumors with severe dislocation of the brainstem causing hydrocephalus showed a higher incidence of CSF leaks. CONCLUSION: Fat implantation is superior to muscle implantation for the prevention of CSF leakage after vestibular schwannoma surgery and should, therefore, be used for the sealing of opened air cells in cranial base surgery.

Distal Roux-en-Y gastric bypass for the treatment of morbid obesity

Background: Classical Roux-en-Y gastric bypass (cRYGB) is a combined restrictive and slightly malabsorptive operation. Excess-BMI-loss (EBMIL) in cRYGB is ~60%, but is diminished for super obese patients (BMI > 50 kg/m2). We therefore designed a modified, mainly malabsorptive distal RYGB (dRYGB). Methods: We report mid-term results after 77 consecutive dRYGB in which malabsorption is inversely related to the length of the common channel. The common channel was 100–150 cm long depending on preoperative BMI, the biliopancreatic limb was 100 cm long, which left >>250 cm for the alimentary channel. To avoid the potentially dangerous combination of malabsorption with sustained restriction the pouch size was increased to ~50ml and a 25 mm circular stapler was used for the gastro-jejunostomy. Results: 33 open and later on 44 laparoscopic interventions have been performed. Median preoperative BMI was 50.2 kg/m 2. No severe intraoperative complications have been observed and no anastomotic leakage was noted in the postoperative period. 5 patients needed balloon dilation of an anastomotic stricture. 3 marginal ulcers occurred at the gastrojejunostomy. The 54 patients with a follow-up time of over 12 months (median 24 months) showed an overall median BMI-reduction of 17 to an actual median BMI of 31.6 kg/m2, corresponding to a EBMIL of 74.5%. Obesity-related comorbid conditions were significantly reduced or cured. Intermittent diarrhea or steatorrhea in 12 patients was easily treated by pancreatic enzyme supplementation. Conclusion: dRYGB is technically more demanding than cRYGB, but shows excellent results in terms of weight-loss and therefore also in reduction of comorbidity especially in super-obese patients. Measuring all three limb lengths allows for a calibration of the malabsorption. The quality of food-intake being important to (super-) obese patients in terms of quality of life, a less restrictive pouch seems more adapted to them. Lifelong multidisciplinary follow-up is mandatory.

Addition of dextran sulfate to blood cardioplegia attenuates reperfusion injury in a porcine model of cardiopulmonary bypass

OBJECTIVE: Contact of blood with artificial surfaces and air as well as ischemia/reperfusion injury to the heart and lungs mediate systemic and local inflammation during cardiopulmonary bypass (CPB). Activation of complement and coagulation cascades leads to and accompanies endothelial cell damage. Therefore, endothelial-targeted cytoprotection with the complement inhibitor and endothelial protectant dextran sulfate (DXS, MW 5000) may attenuate CBP-associated myocardial and pulmonary injury. METHODS: Eighteen pigs (DXS, n=10; phosphate buffered saline [PBS], n=8) underwent standard cardiopulmonary bypass. After aortic cross-clamping, cardiac arrest was initiated with modified Buckberg blood cardioplegia (BCP), repeated after 30 and 60 min with BCP containing either DXS (300 mg/10 ml, equivalent to 5mg/kg) or 10 ml of PBS. Following 30 min reperfusion, pigs were weaned from CPB. During 2h of observation, cardiac function was monitored by echocardiography and invasive pressure measurements. Inflammatory and coagulation markers were assessed regularly. Animals were then sacrificed and heart and lungs analyzed. RESULTS: DXS significantly reduced CK-MB levels (43.4+/-14.8 ng/ml PBS, 35.9+/-11.1 ng/ml DXS, p=0.042) and significantly diminished cytokine release: TNFalpha (1507.6+/-269.2 pg/ml PBS, 222.1+/-125.6 pg/ml DXS, p=0.0071), IL1beta (1081.8+/-203.0 pg/ml PBS, 110.7+/-79.4 pg/ml DXS, p=0.0071), IL-6 (173.0+/-91.5 pg/ml PBS, 40.8+/-19.4 pg/ml DXS, p=0.002) and IL-8 (304.6+/-81.3 pg/ml PBS, 25.4+/-14.2 pg/ml DXS, p=0.0071). Tissue endothelin-1 levels were significantly reduced (6.29+/-1.90 pg/100mg PBS, 3.55+/-1.15 pg/100mg DXS p=0.030) as well as thrombin-anti-thrombin formation (20.7+/-1.0 microg/ml PBS, 12.8+/-4.1 microg/ml DXS, p=0.043). Also DXS reduced cardiac and pulmonary complement deposition, neutrophil infiltration, hemorrhage and pulmonary edema (measured as lung water content, 81+/-3% vs 78+/-3%, p=0.047), indicative of attenuated myocardial and pulmonary CPB-injury. Diastolic left ventricular function (measured as dp/dt(min)), pulmonary artery pressure (21+/-3 mmHg PBS, 19+/-3 mmHg DXS, p=0.002) and right ventricular pressure (21+/-1 mmHg PBS, 19+/-3 mmHg DXS p=0.021) were significantly improved with the use of DXS. CONCLUSIONS: Addition of DXS to the BCP solution ameliorates post-CPB injury and to a certain extent improves cardiopulmonary function. Endothelial protection in addition to myocyte protection may improve post-CPB outcome and recovery.

Different anticoagulation strategies in off-pump coronary artery bypass operations: a European survey

In order to determine anticoagulation strategies in OPCAB a questionnaire survey among 750 European cardio-thoracic surgeons was performed. Questions addressed volume of OPCAB procedures performed, intra- and perioperative heparinization and antiplatelet therapy, as well as perioperative management. A total of 325 (43.7%) questionnaires were returned and validated. Perioperative protocols for administration of antiplatelets differed among the respondent surgeons. Perioperative prophylaxis of thrombosis (low or high molecular weight heparin) is performed by 78%. Intraoperative heparin dosage range between 70 U/kg to 500 U/kg, 60% of respondents prefer a low-dose regimen (< or = 150 U/kg). Correspondingly, the lowest activated clotting time (ACT) during surgery is accepted to be 200 s by 24%, 250 s by 18% and 300 s by 26% of surgeons. Protamine is used by 91% of respondents, while 52% perform a 1:1 reversal. A cell-saver and antifibrinolytics are used by 70% and 40%, respectively. Interestingly, 56% of respondents think bleeding in OPCAB patients is not reduced when compared to on-pump CABG. In addition, 34% of respondents believe there is an increased risk of early graft occlusion following OPCAB. This survey demonstrates widely different intra- and perioperative anticoagulation strategies for OPCAB procedures among European surgeons.

The Shelhigh No-React bovine internal mammary artery: a questionable alternative conduit in coronary bypass surgery?

BACKGROUND: Increasing age and comorbidities among patients undergoing coronary artery bypass surgery (CABG) stimulates the exhaustive research for alternative grafts. No-React treatment should render the tissue resistant against degeneration and reduce early inflammatory response. The aim of the present study was an invasive assessment of the patency of No-React bovine internal mammary artery (NRIMA grafts) used as bypass conduit in CABG surgery. PATIENTS AND METHODS: Nineteen NRIMA grafts were used in 17 patients (2.9%) out of a total of 572 patients undergoing CABG surgery within a 12-month period. All intraoperative data were assessed and in-hospital outcome was analysed. Follow-up examination was performed 7.0+/-4.0 months after initial surgery, including clinical status and coronary angiography to assess patency of the NRIMA grafts. RESULTS: Average perioperative flow of all NRIMA grafts was 71+/-60 ml/min. One patient died in hospital due to a multi-organ failure. Four patients refused invasive assessment. Follow-up was complete in 12 patients with overall 13 NRIMA grafts. Nine NRIMA grafts (69.2%) were used for the right coronary system, two NRIMA grafts (15.4%) on the LAD and two on the circumflex artery. Graft patency was 23.1% and was independent of the intraoperative flow measurement. CONCLUSIONS: NRIMA grafts show a very low patency and cannot be recommended as coronary bypass graft conduits. Patency was independent of the perioperative flow, assessed by Doppler ultrasound. Because of this unsatisfying observation, this type of graft should be utilised as a last resource conduit and used only to revascularise less important target vessels, such as the end branches of the right coronary artery.