Robert J. Beaulieu

Comparison of open and endovascular treatment of acute mesenteric ischemia

INTRODUCTION Acute mesenteric ischemia (AMI) is a commonly fatal result of inadequate bowel perfusion that requires immediate evaluation by both vascular and general surgeons. Treatment often involves vascular repair as well as bowel resection and the possible need for parenteral nutrition. Little data exist regarding the rates of bowel resection following endovascular vs open repair of AMI. METHODS Using the National Inpatient Sample database, admissions from 2005 through 2009 were identified according to International Classification of Diseases, Ninth Revision codes correlating to both AMI (557.0) and subsequent vascular intervention (39.26, 38.16, 38.06, 39.9, 99.10). Patients with a diagnosis of AMI but no intervention or nonemergent admission status were excluded. Patient level data regarding age, gender, and comorbidities were also examined. Outcome measures included mortality, length of stay, the need for bowel resection (45.6, 45.71-9, 45.8), or infusion of total parenteral nutrition (TPN; 99.10) during the same hospitalization. Statistical analysis was conducted by χ(2) tests and Wilcoxon rank-sum comparisons. RESULTS Of 23,744 patients presenting with AMI, 4665 underwent interventional treatment from 2005 through 2009. Of these patients, 57.1% were female, and the mean age was 70.5 years. A total of 679 patients underwent vascular intervention; 514 (75.7%) underwent open surgery and 165 (24.3%) underwent endovascular treatment overall during the study period. The proportion of patients undergoing endovascular repair increased from 11.9% of patients in 2005 to 30.0% in 2009. Severity of comorbidities, as measured by the Charlson index, did not differ significantly between the treatment groups. Mortality was significantly more commonly associated with open revascularization compared with endovascular intervention (39.3% vs 24.9%; P = .01). Length of stay was also significantly longer in the patient group undergoing open revascularization (12.9 vs 17.1 days; P = .006). During the study time period, 14.4% of patients undergoing endovascular procedures required bowel resection compared with 33.4% for open revascularization (P < .001). Endovascular repair was also less commonly associated with requirement for TPN support (13.7% vs 24.4%; P = .025). CONCLUSIONS Endovascular intervention for AMI had increased significantly in the modern era. Among AMI patients undergoing revascularization, endovascular treatment was associated with decreased mortality and shorter length of stay. Furthermore, endovascular intervention was associated with lower rates of bowel resection and need for TPN. Further research is warranted to determine if increased use of endovascular repair could improve overall and gastrointestinal outcomes among patients requiring vascular repair for AMI.

Individualized Performance Feedback to Surgical Residents Improves Appropriate Venous Thromboembolism Prophylaxis Prescription and Reduces Potentially Preventable VTE: A Prospective Cohort Study.

Objective: To investigate the effect of providing personal clinical effectiveness performance feedback to general surgery residents regarding prescription of appropriate venous thromboembolism (VTE) prophylaxis. Background: Residents are frequently charged with prescribing medications for patients, including VTE prophylaxis, but rarely receive individual performance feedback regarding these practice habits. Methods: This prospective cohort study at the Johns Hopkins Hospital compared outcomes across 3 study periods: (1) baseline, (2) scorecard alone, and (3) scorecard plus coaching. All general surgery residents (n = 49) and surgical patients (n = 2420) for whom residents wrote admission orders during the first 9 months of the 2013–2014 academic year were included. Outcomes included the proportions of patients prescribed appropriate VTE prophylaxis, patients with preventable VTE, and residents prescribing appropriate VTE prophylaxis for every patient, and results from the Accreditation Council for Graduate Medical Education resident survey. Results: At baseline, 89.4% of patients were prescribed appropriate VTE prophylaxis and only 45% of residents prescribed appropriate prophylaxis for every patient. During the scorecard period, appropriate VTE prophylaxis prescription significantly increased to 95.4% (P < 0.001). For the scorecard plus coaching period, significantly more residents prescribed appropriate prophylaxis for every patient (78% vs 45%, P = 0.0017). Preventable VTE was eliminated in both intervention periods (0% vs 0.35%, P = 0.046). After providing feedback, significantly more residents reported receiving data about practice habits on the Accreditation Council for Graduate Medical Education resident survey (87% vs 38%, P < 0.001). Conclusions: Providing personal clinical effectiveness feedback including data and peer-to-peer coaching improves resident performance, and results in a significant reduction in harm for patients.

Rates and predictors of readmission after minor lower extremity amputations

OBJECTIVE One goal of the Patient Protection and Affordable Care Act is to reduce hospital readmissions, with financial penalties applied for excessive rates of unplanned readmissions within 30 days among Medicare beneficiaries. Recent data indicate that as many as 24% of Medicare patients require readmission after vascular surgery, although the rate of readmission after limited digital amputations has not been specifically examined. The present study was therefore undertaken to define the rate of unplanned readmission among patients after digital amputations and to identify the factors associated with these readmissions to allow the clinician to implement strategies to reduce readmission rates in the future. METHODS The electronic medical and billing records of all patients undergoing minor amputations (defined as toe or transmetatarsal amputations using International Classification of Diseases, Ninth Revision, codes) from January 2000 through July 2012 were retrospectively reviewed. Data were collected for procedure- and hospital-related variables, level of amputation, length of stay, time to readmission, and level of reamputation. Patient demographics included hypertension, diabetes, hyperlipidemia, smoking history, and history of myocardial infarction, congestive heart failure, peripheral arterial disease, chronic obstructive pulmonary disease, and cerebrovascular accident. RESULTS Minor amputations were performed in 717 patients (62.2% male), including toe amputations in 565 (72.8%) and transmetatarsal amputations in 152 (19.5%). Readmission occurred in 100 patients (13.9%), including 28 (3.9%) within 30 days, 28 (3.9%) between 30 and 60 days, and 44 (6.1%) >60 days after the index amputation. Multivariable analysis revealed that elective admission (P < .001), peripheral arterial disease (P < .001), and chronic renal insufficiency (P = .001) were associated with readmission. The reasons for readmission were infection (49%), ischemia (29%), nonhealing wound (19%), and indeterminate (4%). Reamputation occurred in 95 (95%) of the readmitted patients, including limb amputation in 64 (64%) of the patients (below knee in 58, through knee in 2, and above knee in 4). CONCLUSIONS Readmission after minor amputation was associated with limb amputation in the majority of cases. This study identified a number of nonmodifiable patient factors that are associated with an increased risk of readmission. Whereas efforts to reduce unplanned hospital readmissions are laudable, payers and regulators should consider these observations in defining unacceptable rates of readmission. Further, although beyond the scope of this study, it is not unreasonable to assume that pressure to reduce readmission rates in the population of patients with extensive comorbidity may induce practitioners to undertake amputation at a higher level initially to minimize the risk of readmission for reamputation and associated financial penalties and thus deprive the patient the chance for limb salvage.

Contralateral occlusion is not a clinically important reason for choosing carotid artery stenting for patients with significant carotid artery stenosis

OBJECTIVE Contralateral carotid artery occlusion by itself carries an increased risk of stroke. Carotid endarterectomy (CEA) in the presence of contralateral carotid artery occlusion has high reported rates of perioperative morbidity and mortality. Our objective was to determine if there is a clinical benefit to patients who receive carotid artery stenting (CAS) compared to CEA in the presence of contralateral carotid artery occlusion. METHODS We conducted a retrospective medical chart review over a 4.5-year institutional experience of persons with contralateral carotid artery occlusion and ipsilateral carotid artery stenosis who underwent CAS or CEA. The main outcome measures were 30-day cardiac, stroke, and mortality rate, and midterm mortality. RESULTS Of a total of 713 patients treated for carotid artery stenosis during this time period, 57 had contralateral occlusion (~8%). Thirty-nine of these patients were treated with CAS, and 18 with CEA. The most common indications for CAS were prior neck surgery (18), contralateral internal carotid occlusion (nine), and prior neck radiation (seven). The average age was 70 ± 8.5 for CEA and 66.7 ± 9.3 for CAS (P = .20). Both groups were predominantly men (CEA 12 of 18; CAS 28 of 39; P = .76), with similar prevalence of symptomatic lesions (CEA 8 of 18, CAS 20 of 39; P = .77). Two patients died within 30 days in the CAS group (5%). No deaths occurred within 30 days in the CEA group (P = .50); the mortality rate for CAS and CEA combined was 3.5%. No perioperative strokes or myocardial infarction occurred in either group. Two transient ischemic attacks occurred after CAS. At mean follow-up of 29.4 ± 16 months (CEA) and 28 ± 14.4 months (CAS; range, 1.5-48.5 months), seven deaths occurred in the CAS group and one in the CEA group (17.9% vs 5.5%; P = .40). There were two reinterventions in the CAS group for in-stent restenosis and there were no reoperations in the CEA group. CONCLUSIONS Although CEA and CAS can both be performed with good perioperative results and acceptable midterm mortality, the observed outcomes do not support use of contralateral carotid artery occlusion as a selection criterion for CAS over CEA in the absence of other indications.

Cohort comparison of thoracic endovascular aortic repair with open thoracic aortic repair using modern end-organ preservation strategies.

BACKGROUND Pivotal trials showed that thoracic endovascular aortic repair (TEVAR) has improved outcomes compared with open surgery for treating descending thoracic aortic aneurysms. However, those trials included historical open controls in which modern end-organ preservation strategies were not routinely employed. To create a more level assessment, we compared our outcomes of elective TEVAR with modern open thoracic aortic repair (OTAR) controls. METHODS A retrospective review of thoracic aortic aneurysm patients undergoing TEVAR was compared with a contemporaneous cohort of OTAR patients. Partial bypass or hypothermic circulatory arrest was used in all OTAR patients. Cerebrospinal fluid drain placement was attempted in all patients. Preoperative characteristics, operative variables, and outcomes were recorded, and the Kaplan-Meier method was used for survival estimates. RESULTS The main outcome was mortality. Secondary outcomes included postoperative spinal cord ischemia (SCI) or stroke, and any persistent neurologic deficit 30 days following the operation. During the study period, 62 patients underwent TEVAR and 56 underwent OTAR with median follow-up of 23.7 months and 36.4 months, respectively. No difference existed between the TEVAR and OTAR with respect to overall neurologic complications (8.1% vs. 12.5%, P = 0.55) as well as any residual neurologic deficit at 30 days (0% vs. 5.4%, P = 0.10). TEVAR patients had fewer complications including pneumonia (P = 0.02), rebleeding (P = 0.02), and acute kidney injury (P = 0.001). There was no difference in 30-day mortality (1.6% vs. 8.9%, P = 0.10), 1-year mortality (12.2% vs. 14%, P = 0.80), or 5-year mortality (53.9% vs. 44%, P = 0.48) between TEVAR and OTAR, respectively. CONCLUSIONS TEVAR continues to show improved perioperative outcomes with a trend toward decreased 30-day mortality and fewer major adverse events compared with OTAR. However, with the routine use of end-organ preservation strategies during OTAR, neurologic deficits, particularly SCI, can be safely reduced to comparable levels with those of TEVAR and 1-year all-cause mortality rates are similar between the groups. These OTAR results may serve as a benchmark as TEVAR is increasingly applied for other aortic pathologies, such as chronic dissection, wherein long-term efficacy is not proven.

Fistula-in-ano: When to Cut, Tie, Plug, or Sew

IntroductionManagement of fistula-in-ano requires understanding of both perianal and rectal anatomy, as well as the surgical approaches available to ensure the highest possible postoperative continence and wound healing. Further, high rates of recurrence with medical management commonly bring these patients under the care of the colorectal surgeon after variable periods of failed conservative management. Novel techniques provide surgeons with tools to treat increasingly complex fistulas with a focus on maintaining sphincteric functionality and limiting recurrence.MethodThis manuscript presents our practice, including perioperative decision making regarding surgical approach, in managing patients with fistula-in-ano.ConclusionFamiliarity with these techniques prepares the general surgeon and colorectal surgeon to improve wound healing and functional outcomes in these patients, especially with complex disease involving the external and internal anal sphincters.

Malperfusion syndromes in aortic dissections

Aortic dissection remains a challenging clinical scenario, especially when complicated by peripheral malperfusion. Improvements in medical imaging have furthered understanding of the pathophysiology of malperfusion events in association with aortic dissection, including the elucidation of different mechanisms of branch vessel obstruction. Despite these advances, malperfusion syndrome remains a deadly entity with significant mortality. This review presents the latest knowledge regarding the pathogenesis of aortic dissection complicated by malperfusion syndrome, and discusses the diagnostic and therapeutic guidelines for management of this vicious entity.

A CMOS Current Steering Neurostimulation Array With Integrated DAC Calibration and Charge Balancing

An 8-channel current steerable, multi-phasic neural stimulator with on-chip current DAC calibration and residue nulling for precise charge balancing is presented. Each channel consists of two sub-binary radix DACs followed by wide-swing, high output impedance current buffers providing time-multiplexed source and sink outputs for anodic and cathodic stimulation. A single integrator is shared among channels and serves to calibrate DAC coefficients and to closely match the anodic and cathodic stimulation phases. Following calibration, the differential non-linearity is within

Efficacy of Axillary to Femoral Vein Bypass in Relieving Venous Hypertension in Dialysis Patients with Symptomatic Central Vein Occlusion

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Automated diagnosis of colon cancer using hyperspectral sensing

LSB at 8-bit resolution, and the two stimulation phases are matched within 0.3%. Individual control in digital programming of stimulation coefficients across the array allows altering the spatial profile of current stimulation for selection of stimulation targets by current steering. Combined with the self-calibration and current matching functions, the current steering capabilities integrated on-chip support use in fully implanted neural interfaces with autonomous operation for and adaptive stimulation under variations in electrode and tissue conditions. As a proof-of-concept we applied current steering stimulation through a multi-channel cuff electrode on the sciatic nerve of a rat.