Spectrum of ascending aortic aneurysms at a peri-urban tertiary hospital: an echocardiography-based study.

Introduction: Thoracic ascending aortic (TAA) aneurysms are an important cause of disability and death and require early detection for effective management. Currently, there is a paucity of data from Africa pertaining to TAA aneurysms. This study describes the spectrum of TAA aneurysms at a peri-urban tertiary hospital. Methods: A descriptive retrospective study based on clinical and echocardiographic imaging data of patients with TAA aneurysms from October 2017-October 2022. Advanced strain imaging was performed to measure left ventricular (LV) basal, apical, and global longitudinal strain as well as circumferential strain (CS) of the ascending aorta as a proxy measurement of aortic compliance. Results: The study comprised 139 cases of TAA aneurysms (52.5% females) with a mean age of 50 ± 14.8 years with 45 age and gender matched controls. Most cases (95%) were of African ethnicity. The main etiologies were hypertension (41.7%), HIV (36.6%), connective tissue disease (10.7%), congenital (2.2%) and mixed pathologies (8.6%). Two-thirds of patients (69.7%) presented in heart failure, 10% presented with aortic dissection. Thirty percent of the patients were classified as New York Heart Association (NYHA) class I, 59.7% NYHA II, 8.6% NYHA III and two patients NYHA class IV. Echocardiography revealed enlarged aortic dimensions compared to controls (P < 0.001). TAA aneurysms were complicated by severe aortic regurgitation (AR) in half (50.3%) of patients, moderate AR in 25.8%, and mild AR in 14.3%. The mean LV ejection fraction (46.9 ± 12.7%) was reduced compared to controls (P < 0.001). Aortic CS was reduced compared to controls [4.4 (3.2-6.2) % vs. 9.0 (7.1-13.4) %, P < 0.001]. Aortic stiffness was higher in the aortic aneurysm group compared to controls (15.39 ± 20.65 vs. 5.04 ± 2.09, P = 0.001). LV longitudinal strain (-13.9 ± 3.9% vs. 18.1 ± 6.7%), basal CS (-13.9 ± 5.6% vs. -17.9 ± 5.8%) and apical CS (-8.7 ± 8.5% vs. -30.6 ± 3.8%) were reduced compared to controls (P < 0.001). Most patients were on diuretic and anti-remodeling therapy. Surgery was performed in 29.4% and overall mortality was 7.9%. Mortality for acute aortic dissection was 40%. Conclusion: TAA aneurysms associated with hypertension and HIV are common in this predominantly African female population and are associated with considerable morbidity and mortality. Two-dimensional echocardiography and advanced strain imaging are potential tools for detecting and risk stratifying TAA aneurysms.

Two-dimensional echocardiographic and strain values of the proximal thoracic aorta in a normal sub-Saharan African population.

BACKGROUND: There is limited data regarding reference ranges for aortic dimensions in African populations. This study aims to establish normal reference ranges for echocardiographic dimensions and circumferential strain (CS) of the proximal thoracic aorta in a healthy sub-Saharan African population. METHODS: This was a secondary analysis of data from a prospective cross-sectional study of 88 participants conducted at Chris Hani Baragwanath Hospital (2017-2019). Aortic measurements were obtained as per the 2015 American Society of Echocardiography guidelines using a Philips iE33 system. Circumferential Strain was measured using Philips QLAB version 11.0 software offline semi-automated analysis of speckle-based strain 2-D speckle-tracking software (Amsterdam, The Netherlands). RESULTS: Mean age was 37.22 ± 10.79 years (41% male). The mean diameter at the aortic annulus, sinuses, sino-tubular junction (STJ) and ascending aorta (AAO) were 19.11 ± 2.38 mm, 27.40 ± 6.11 mm, 25.32 ± 3.52 mm and 25.36 ± 3.38 mm, respectively. Males had larger absolute and indexed aortic diameters at all levels when compared to females. The mean aorta CS was 11.97 ± 5.05%. There was no significant difference in CS based on gender (12.19 ± 5.04% vs 11.51 ± 5.02%, P = 0.267). On multivariate linear regression analysis, male sex was the most significant predictor of increased diameter at the level of the aortic annulus (r = 0.17, P = 0.014), body surface area was the most significant predictor at the sinuses (r = 0.17, P = 0.014) and AAO (r = 0.30, P < 0.001), while age was the most significant predictor at the STJ (r = 0.27, P = 0.004). There was a negative correlation between age and aortic CS (r = - 0.12, P < 0.001). The most important predictor of aorta CS was age, on multivariate analysis (r = - 0.19, P = 0.024). CONCLUSIONS: This study provides normal reference ranges for dimensions of the proximal aorta and circumferential strain (CS) in a sub-Saharan African population according to age, sex, and body habitus. It serves as a platform for future larger studies and allows for risk stratification of cardiovascular disease in an African population.

Routine intraoperative leak testing for sleeve gastrectomy: is the leak test full of hot air?

BACKGROUND: Staple line leak after sleeve gastrectomy (SG) is a rare but dreaded complication with a reported incidence of 0% to 8%. Many surgeons routinely test the staple line with an intraoperative leak test (IOLT), but there is little evidence to validate this practice. In fact, there is a theoretical concern that the leak test may weaken the staple line and increase the risk of a postop leak. METHODS: Retrospective review of all SGs performed over a 7-year period was conducted. Cases were grouped by whether an IOLT was performed, and compared for the incidence of postop staple line leaks. The ability of the IOLT for identifying a staple line defect and for predicting a postoperative leak was analyzed. RESULTS: Five hundred forty-two SGs were performed between 2007 and 2014. Thirteen patients (2.4%) developed a postop staple line leak. The majority of patients (n = 494, 91%) received an IOLT, including all 13 patients (100%) who developed a subsequent clinical leak. There were no (0%) positive IOLTs and no additional interventions were performed based on the IOLT. The IOLT sensitivity and positive predictive value were both 0%. There was a trend, although not significant, to increase leak rates when a routine IOLT was performed vs no routine IOLT (2.6% vs 0%, P = .6). CONCLUSIONS: The performance of routine IOLT after SG provided no actionable information, and was negative in all patients who developed a postoperative leak. The routine use of an IOLT did not reduce the incidence of postop leak, and in fact was associated with a higher leak rate after SG.

The routine use of prosthetic mesh in austere environments: dogma vs data.

BACKGROUND: Mesh repair has become the standard in adult hernia repairs. Mesh infection is an uncommon but potentially devastating complication. Currently, there is widespread dogma against the use of prosthetic mesh (PM) in deployed or austere environments but little available data to support or refute this bias. METHODS: Retrospective review of all hernia repairs over 1 year in a forward deployed surgical unit in Afghanistan. Demographics, hernia type, repair performed, and mesh type were evaluated. Follow-up was completed up to 6 weeks and then as needed for up to a year, and complications to include infection were recorded. RESULTS: Sixty-six patients were identified, mean age was 38 (range 3 to 80) and 98% were male. Single-dose perioperative antibiotics and standard sterile technique were used in all cases. The majority (70%) had PM placed. The mean operative time was 54 min, and mean estimated blood loss was less than 25 cm(3). The vast majority of our hernias were inguinal (95%) with 1 ventral and 2 umbilical hernias. In the PM group, there were no surgical site infections, no mesh infections, and no mesh explantation or reoperation. There were no recurrences in either group identified at up to 1-year postoperation. There was no statistically significant difference in any outcome measure between the PM and no-PM groups. CONCLUSIONS: The use of PM for hernia repairs in the austere or forward environment appears safe and did not increase the risk of wound infection, mesh infections, or recurrence.

Laparoscopic sleeve gastrectomy in patients with preexisting gastroesophageal reflux disease : a national analysis.

OBJECTIVES: To analyze the effect of laparoscopic sleeve gastrectomy (LSG) on patients with gastroesophageal reflux disease (GERD) and to compare the results of LSG vs gastric bypass (GB) among patients with known GERD. DESIGN, SETTING, AND PATIENTS: We performed a retrospective review of the Bariatric Outcomes Longitudinal Database from January 1, 2007, through December 31, 2010, including inpatient and all outpatient follow-up data. We compared patients undergoing LSG with a concurrent cohort undergoing GB. MAIN OUTCOMES AND MEASURES: Rates of improvement or worsening of GERD symptoms, development of new-onset GERD, and weight loss and complications. RESULTS: A total of 4832 patients underwent LSG and 33 867 underwent GB, with preexisting GERD present in 44.5% of the LSG cohort and 50.4% of the GB cohort. Most LSG patients (84.1%) continued to have GERD symptoms postoperatively, with only 15.9% demonstrating GERD resolution. Of LSG patients who did not demonstrate preoperative GERD, 8.6% developed GERD postoperatively. In comparison, GB resolved GERD in most patients (62.8%) within 6 months postoperatively (P < .001). Among the LSG cohort, the presence of preoperative GERD was associated with increased postoperative complications (15.1% vs 10.6%), gastrointestinal adverse events (6.9% vs 3.6%), and increased need for revisional surgery (0.6% vs 0.3%) (all P < .05). The presence of GERD had no effect on weight loss for the GB cohort but was associated with decreased weight loss in the LSG group. CONCLUSIONS AND RELEVANCE: Laparoscopic sleeve gastrectomy did not reliably relieve or improve GERD symptoms and induced GERD in some previously asymptomatic patients. Preoperative GERD was associated with worse outcomes and decreased weight loss with LSG and may represent a relative contraindication.

Physiology and cardiovascular effect of severe tension pneumothorax in a porcine model.

BACKGROUND: Pneumothoraces are relatively common among trauma patients and can rapidly progress to tension physiology and death if not identified and treated. We sought to develop a reliable and reproducible large animal model of tension pneumothorax and to examine the cardiovascular effects during progression from simple pneumothorax to tension pneumothorax. MATERIALS AND METHODS: Ten swine were intubated, sedated, and placed on mechanical ventilation. After a midline celiotomy, a 10-mm balloon-tipped laparoscopic trocar was placed through the diaphragm, and a 28F chest tube was placed in the standard position and clamped. Thoracic insufflation was performed in 5-mm increments, and continuous cardiovascular measurements were obtained. RESULTS: Mean insufflation pressures of 10 mm Hg were associated with a 67% decrease in cardiac output (6.6 L/min versus 2.2 l/min; P = 0.04). An additional increase in the insufflation pressure (mean 15 mm Hg) was associated with an 82% decrease in cardiac output from baseline (6.8 versus 1.2 L/min; P < 0.01). Increasing insufflation pressures were associated with a corresponding increase in central venous pressure (from 7.6 mm Hg to 15.2 mm Hg; P < 0.01) and a simultaneous decrease in the pulmonary artery diastolic pressure (from 15 mm Hg to 12 mm Hg; P = 0.06), with the central venous pressure and pulmonary artery diastolic pressure approaching equalization immediately before the development of major hemodynamic decline. Pulseless electrical activity arrest was induced at an average of 20 mm Hg. Tension physiology was immediately reversible with adequate decompression, allowing for multiple repeated trials. CONCLUSIONS: A reliable and highly reproducible model was created for severe tension pneumothorax in a large animal. Major cardiovascular instability proceeding to pulseless electrical activity arrest with stepwise insufflation was noted. This model could be highly useful for studying new diagnostic and treatment modalities for tension pneumothorax.

Optimum cystic duct closure: a comparative study using metallic clips, ENSEAL, and ENDOLOOP in swine.

BACKGROUND: Metal clips are commonly used to secure the cystic duct during cholecystectomy, although use of an ENDOLOOP (Ethicon Endo-Surgery, Blue Ash, OH) is often touted as a more secure closure when postoperative endoscopic retrograde cholangiopancreatography (ERCP) is anticipated. The objective of this study was to test the strength of 3 different cystic duct closure methods in a model simulating postoperative biliary insufflation. METHODS: The extrahepatic biliary system, including common bile duct, gallbladder, and cystic duct, was harvested en bloc from 22 swine postmortem. A cholecystectomy was performed and the cystic duct was secured using 1 of 3 randomly assigned methods: metallic clips (Ethicon Endo-Surgery), an ENDOLOOP (Ethicon Endo-Surgery), or an ENSEAL tissue sealing device (Ethicon Endo-Surgery). The common bile duct was cannulated with a pressure-monitoring system and insufflated with air. The burst pressures, location of rupture, and size of the common bile duct and cystic duct were recorded and compared. RESULTS: There were 7 pigs each in the ENDOLOOP and ENSEAL groups and 8 in the metallic clip group, with no statistical significance between cystic and common bile duct size. Mean burst pressure was 432 mm Hg for metallic clips, 371 mm Hg for the ENDOLOOP, and 238 mm Hg for the ENSEAL device (P = .02). Post hoc analysis revealed clips to be statistically superior when compared with the ENSEAL (P= .01). There was no statistical difference between the ENDOLOOP and metal clips or between the ENDOLOOP and the ENSEAL. CONCLUSIONS: All 3 closure methods successfully secured the cystic duct, with mean burst pressures exceeding 195 mm Hg. Metallic clips demonstrated the highest burst pressures and no cystic duct stump leaks. This study challenges the traditional dogma of additionally securing the cystic duct with an ENDOLOOP when postoperative biliary instrumentation is expected and also suggests that an adequately secure closure may be obtained with thermal sealing devices.

Analysis of obesity-related outcomes and bariatric failure rates with the duodenal switch vs gastric bypass for morbid obesity.

OBJECTIVE: To compare the outcomes of a large cohort undergoing biliopancreatic diversion/duodenal switch (DS) vs gastric bypass (GB). DESIGN: Retrospective review of the Bariatric Outcomes Longitudinal Database from 2007 to 2010. All inpatient and outpatient follow-up data were analyzed. SETTING: Multicenter database. PATIENTS: Patients undergoing primary DS were compared with a concurrent cohort undergoing GB. MAIN OUTCOME MEASURES: The main outcome measures were (1) weight loss; (2) control of comorbidities including diabetes mellitus, hypertension, and sleep apnea; and (3) failure to achieve at least 50% excess body weight loss. RESULTS: One thousand five hundred forty-five patients underwent DS and 77 406 underwent GB, with a mean preoperative body mass index (BMI; calculated as weight in kilograms divided by height in meters squared) of 52 and 48, respectively (P < .01). The DS was associated with longer operative times, greater blood loss, and longer lengths of hospital stay (all P < .05). Early reoperation rates were higher in the DS group (3.3% vs 1.5%). Percentage of change in BMI was significantly greater in the DS group at all follow-up intervals (P < .05). Subgroup analysis of the superobese population (BMI >50) revealed significantly greater percentage of excess body weight loss in the DS group at 2 years (79% vs 67%; P < .01). Comorbidity control of diabetes, hypertension, and sleep apnea were all superior with the DS (all P < .05). The risk of weight loss failure was significantly reduced with DS vs GB for all patients, with a greater reduction in the BMI more than 50 subgroup. CONCLUSIONS: The DS is a less commonly used bariatric operation, with higher early risks compared with GB. However, the DS achieved better weight and comorbidity control, with even more pronounced benefits among the superobese.

Does needle thoracostomy provide adequate and effective decompression of tension pneumothorax?

BACKGROUND: Tension pneumothorax (tPTX) is a common and potentially fatal event after thoracic trauma. Needle decompression is the currently accepted first-line intervention but has not been well validated. The purpose of this study was to evaluate the effectiveness of a properly placed and patent needle thoracostomy (NT) compared with standard tube thoracostomy (TT) in a swine model of tPTX. METHODS: Six adult swine underwent instrumentation and creation of tPTX using thoracic CO2 insufflation via a balloon trocar. A continued 1 L/min insufflation was maintained to simulate an ongoing air leak. The efficacy and failure rate of NT (14 gauge) compared with TT (34F) was assessed in two separate arms: (1) tPTX with hemodynamic compromise and (2) tPTX until pulseless electrical activity (PEA) obtained. Hemodynamics was assessed at 1 and 5 minutes after each intervention. RESULTS: A reliable and highly reproducible tPTX was created in all animals with a mean insufflation volume of 2441 mL. tPTX resulted in the systolic blood pressure declining 54% from baseline (128-58 mm Hg), cardiac output declining by 77% (7-1.6 L/min), and equalization of central venous pressure and wedge pressures. In the first arm, there were 19 tPTX events treated with NT placement. All NTs were patent on initial placement, but 5 (26%) demonstrated mechanical failure (due to kinking, obstruction, or dislodgment) within 5 minutes of placement, all associated with hemodynamic decline. Among the 14 NTs that remained patent at 5 minutes, 6 (43%) failed to relieve tension physiology for an overall failure rate of 58%. Decompression with TT was successful in relieving tPTX in 100%. In the second arm, there were 21 tPTX with PEA events treated initially with either NT (n = 14) or TT (n = 7). The NT failed to restore perfusion in nine events (64%), whereas TT was successful in 100% of events as a primary intervention and restored perfusion as a rescue intervention in eight of the nine NT failures (88%). CONCLUSION: Thoracic insufflation produced a reliable and easily controlled model of tPTX. NT was associated with high failure rates for relief of tension physiology and for treatment of tPTX-induced PEA and was due to both mechanical failure and inadequate tPTX evacuation. This performance data should be considered in future NT guideline development and equipment design.

The duodenal switch for morbid obesity: modification of cardiovascular risk markers compared with standard bariatric surgeries.

BACKGROUND: Obesity is associated with cardiovascular risk factors such as lipid levels and increased levels of C-reactive peptide (CRP). We hypothesized that duodenal switch (DS) would show equivalent or superior risk reduction compared with standard bariatric surgeries. METHODS: Patients underwent DS, sleeve gastrectomy (SG), or gastric bypass (GB) over a 2-year period. Body mass index (BMI), lipid panel, and CRP were measured preoperatively and then 3, 6, and 12 months postoperatively. RESULTS: A total of 130 patients were identified; 42 underwent DS, 40 underwent SG, and 48 underwent GB. All groups had similar sex and comorbidity profiles, but the mean preoperative BMI was greatest in the DS group (mean = 52). At all intervals weight loss was greater in the DS group (P < .01), with a final BMI of 31 for the DS group, 31 for the SG group, and 28 for the GB group. Cholesterol and low-density lipoprotein showed significantly greater improvement at all time points with DS compared with SG and GB (P < .01). Baseline CRP levels among DS patients were double that of SG and GB, but rapidly declined to equivalent levels by 3 months and normalized in 79%. CONCLUSIONS: The DS procedure resulted in a superior reduction in cardiovascular and proinflammatory risk markers compared with GB and SG.

Hyperacute lung rejection in the pig-to-human model 4: evidence for complement and antibody independent mechanisms.

BACKGROUND: We assessed whether the combination of complement regulation and depletion of xenoreactive antibodies improves the outcome of pulmonary xenografts compared with either strategy alone. METHODS: Lungs from pigs heterozygous (hDAF(+/-)) or homozygous (hDAF(+/+)) for the human decay accelerating factor transgene (hDAF) or their nontransgenic litter mates (hDAF(-/-)) were perfused with heparinized whole human blood. In additional groups, xenoreactive natural antibodies (XNA) were depleted by pig lung perfusion (hDAF(-/-)/AbAbs, hDAF(+/-)/AbAbs) before the experiment. This combined approach was augmented by adding soluble complement receptor 1 (sCR1) to the perfusate in one further group (hDAF(+/-)/AbAbs/sCR1). RESULTS: HDAF(-/-) lungs perfused with unmodified human blood were rejected after 32.5 min (interquartile range, IQR 5 to 210). HDAF(+/-) lungs survived for 90 min (IQR 10 to 161, P = 0.54). Both groups showed a rapid rise in pulmonary vascular resistance (PVR), which is a characteristic feature of hyperacute rejection (HAR). This phenomenon was blunted in the hDAF(+/+) group, although survival (48 min, IQR 14 to 111) was not further prolonged. Antibody depletion (AbAbs) led to a significant increase in survival time (hDAF(-/-)/AbAbs: 315 min, IQR 230 to 427; hDAF(+/-)/AbAbs: 375 min, IQR 154 to 575), reduced PVR and less complement production. Addition of sCR1 reduced complement elaboration but did not further improve survival (200 min, IQR 128 to 580) and surprisingly tended to increase PVR. CONCLUSIONS: Depletion of xenoreactive antibodies is more effective than membrane-bound complement regulation to blunt hyperacute rejection of pulmonary xenografts, but even the combined approach including soluble-phase complement inhibition is not sufficient to reliably prevent organ failure within hours. It therefore seems likely that other factors independent of antibody and complement contribute to HAR in this model.