Evaluation of the Efficacy of a Novel Dermatotomy Device for Central Venous Cannulation.

OBJECTIVE: To test the effectiveness of a novel wire-guided scalpel (Guideblade) to create a precise dermatotomy incision for central venous catheter (CVC) insertion. DESIGN: Prospective, nonrandomized interventional study. SETTING: Stanford University, single-center teaching hospital. PARTICIPANTS: Cardiac and vascular surgical patients (n = 100) with planned CVC insertion for operation. INTERVENTIONS: A wire-guided scalpel was used during CVC insertion. RESULTS: A total of 188 CVCs were performed successfully with a wire-guided scalpel without the need for additional equipment in 100 patients, and 94% of CVCs were accomplished with only a single dermatotomy attempt. "No bleeding" or "minimal bleeding" at the insertion site was observed in 90% of patients 30 minutes after insertion and 80.7% at the conclusion of surgery. CONCLUSION: The wire-guided scalpel was effective in performing dermatotomy for CVC with a 100% success rate and a very high first-attempt rate. The wire-guided scalpel may decrease bleeding at the CVC insertion site.

The Penn Classification Predicts Hospital Mortality in Acute Stanford Type A and Type B Aortic Dissections.

OBJECTIVES: Mortality in acute aortic dissection varies depending on anatomic location, extent, and associated complications. The Stanford classification guides surgical versus medical management. The Penn classification stratifies mortality risk in patients with Stanford type A aortic dissections undergoing surgery. The objective of the present study was to determine whether the Penn classification can predict hospital mortality in patients with acute Stanford type A and type B aortic dissections undergoing surgical or medical management. DESIGN: Retrospective, observational study. SETTING: Tertiary care, university hospital. PARTICIPANTS: Patients with acute aortic dissection between January 2008 and December 2017. INTERVENTIONS: Examination of hospital mortality after surgical or medical management. MEASUREMENTS AND MAIN RESULTS: Three hundred fifty-two patients had confirmed dissections (186 type A, 166 type B). The overall mortality was 18.8% for type A and 13.3% for type B. Penn class A patients with type A or type B dissections undergoing surgical repair had the lowest mortality (both 3.1%). Penn class B, C, or B+C patients with type A dissections and Penn class B+C patients with type B dissections undergoing medical management had the greatest incidence of mortality (50.0%-57.1%). All others had intermediate mortality (6.7%-39.3%). Logistic regression analysis demonstrated that Penn class B, C, and B+C patients had a greater odds of mortality and predicted mortality than did Penn class A patients. CONCLUSIONS: The Penn classification predicts hospital mortality in patients with acute Stanford type A or type B aortic dissections undergoing surgical or medical management. Early endovascular repair may confer lower risk of mortality in patients with type B dissections presenting without ischemia.

The "Ice Age" in Cardiac Surgery: Evolution of the "Siberian" Method of Brain Protection During Deep Hypothermic Perfusionless Circulatory Arrest.

Deep hypothermic perfusionless circulatory arrest was the first practical neuroprotective technique used for open-heart surgery. It was refined at the Novosibirsk Medical Research Center in Siberia and was actively used from the mid-1950s until 2001.This review describes the development of this technique and its contribution to our understanding of the dynamic changes in human physiology during induced hypothermia for circulatory arrest without extracorporeal perfusion. Deep hypothermic perfusionless circulatory arrest was an important stepping stone in the development of modern approaches in neuroprotection and monitoring during cardiac surgery.

Protocol for prevention of spinal cord ischemia after thoracoabdominal aortic surgery.

OBJECTIVE: This manuscript was written to present a systemic protocol for the prevention, early detection, and treatment of spinal cord ischemia following open and endovascular thoracoabdominal aortic operations. METHODS: This protocol was a collaborative effort between surgeons, anesthesiologists and intensivists. It was implemented at our institution in November 2007. Nurses are trained to prevent, rapidly detect and ultimately aid in the treatment of spinal cord ischemia. RESULTS: Implementation of this protocol has aided in prevention, detection and treatment of spinal cord ischemia in patients after open and endovascular thoracoabdominal aortic operations. CONCLUSION: Standardized care and reliance on trained nursing staff to monitor for symptoms following thoracoabdominal aortic operations are safe and aid in the rapid detection, treatment and reversal of spinal cord ischemia.

Severity and Duration of Metabolic Acidosis After Deep Hypothermic Circulatory Arrest for Thoracic Aortic Surgery.

OBJECTIVE: To determine the severity, duration, and contributing factors for metabolic acidosis after deep hypothermic circulatory arrest (DHCA). DESIGN: Retrospective observational study. SETTING: University hospital. PATIENTS: Eighty-seven consecutive patients undergoing elective thoracic aortic surgery with DHCA. INTERVENTIONS: Regression analysis was used to test for relationships between the severity of metabolic acidosis and clinical and laboratory variables. MEASUREMENTS AND MAIN RESULTS: Minimum pH averaged 7.27±0.06, with 76 (87%) having a pH<7.35; 55 (63%), a pH<7.30; and 7 (8%), a pH<7.20. The mean duration of metabolic acidosis was 7.9±5.0 hours (range: 0.0 - 26.8), and time to minimum pH after DHCA was 4.3±2.0 hours (1.0 - 10.0 hours). Hyperchloremia contributed to metabolic acidosis in 89% of patients. The severity of metabolic acidosis correlated with maximum lactate (p<0.0001) and hospital length of stay (LOS) (r = 0.22, p<0.05), but not with DHCA time, DHCA temperature, duration of vasoactive infusions, or ICU LOS. Patient BMI was the sole preoperative predictor of the severity of postoperative metabolic acidosis. LIMITATIONS: This retrospective analysis involved short-term clinical outcomes related to pH severity and duration, which indirectly may have included the impact of sodium bicarbonate administration. CONCLUSIONS: Metabolic acidosis was common and severe after DHCA and was attributed to both lactic and hyperchloremic acidosis. DHCA duration and temperature had little impact on the severity of metabolic acidosis. The severity of metabolic acidosis was best predicted by the BMI and had minimal effects on short-term outcomes. Preventing hyperchloremic acidosis has the potential to decrease the severity of metabolic acidosis after DHCA.

Reversible spinal cord ischemia as a complication of acute aortic intramural hematoma.

Aortic intramural hematoma is a variant of acute aortic dissection characterized by localized hemorrhage into the aortic media causing a separation of the intimal and adventitial layers of the aorta. Malperfusion represents an unusual presenting sign of acute intramural hematoma. Herein, we describe the case of a patient with an acute Type A IMH who developed reversible ischemic spinal cord syndrome after presenting with paraplegia as a consequence of malperfusion. A decision was made to delay operative repair and, instead, emergently apply medical interventions to increase spinal cord perfusion pressure. Medical treatment was effective for the treatment of spinal cord ischemia and operative repair of the intramural hematoma was accomplished after complete recovery of neurologic function. This is the third case ever reported of an intramural hematoma presenting in the form of spinal cord ischemia.

A pilot study of darbepoetin alfa for prophylactic neuroprotection in aortic surgery.

BACKGROUND: Descending aortic (DA) surgery poses a high risk for spinal and cerebral infarction and routine use of lumbar drains allows for measurement of CSF markers of neurologic injury. Erythropoiesis medications have extensive preclinical data demonstrating neuroprotection. We hypothesized that prophylactic darbepoetin alfa (DARB) given before surgery reduces neurologic injury in patients undergoing DA repair. METHODS AND RESULTS: We performed a prospective adaptive dose-finding trial of prophylactic DARB ( www.clinicaltrials.gov NCT00647998) that terminated prematurely following publication of an erythropoietin stroke study showing possible harm. Enrollment halted before dose adjustments; nine patients each received 1 mg/kg IV DARB immediately before surgery. A prospective cohort of nine untreated patients was subsequently obtained for comparison. The primary outcome of death or neurologic impairment at discharge occurred in 1/9 (11 %) DARB patients and 3/9 (33 %) controls (p = 0.58). There were no statistical differences in changes of CSF biomarkers from baseline to 48 h comparing DARB patients to controls: S100ß, median 214 versus 260 ng/ml (p = 0.69); glial fibrillary acidic protein (GFAP), median 0.022 versus 0.58 ng/ml (p = 0.45). In patients with early perioperative neurologic ischemia, there were greater changes in CSF biomarkers, compared to those without ischemia: S100ß, median 2301 versus 124 ng/ml (p = 0.04); GFAP, median 31.78 versus 0.31 ng/ml (p = 0.34). CONCLUSIONS: There were no significant effects of prophylactic DARB on clinical outcome or CSF markers of neurologic injury in this pilot study, although all point estimates favored treatment. DA repair is a promising model of prophylactic neuroprotection.

Strain estimation in aortic roots from 4D echocardiographic images using medial modeling and deformable registration.

Even though the central role of mechanics in the cardiovascular system is widely recognized, estimating mechanical deformation and strains in-vivo remains an ongoing practical challenge. Herein, we present a semi-automated framework to estimate strains from four-dimensional (4D) echocardiographic images and apply it to the aortic roots of patients with normal trileaflet aortic valves (TAV) and congenital bicuspid aortic valves (BAV). The method is based on fully nonlinear shell-based kinematics, which divides the strains into in-plane (shear and dilatational) and out-of-plane components. The results indicate that, even for size-matched non-aneurysmal aortic roots, BAV patients experience larger regional shear strains in their aortic roots. This elevated strains might be a contributing factor to the higher risk of aneurysm development in BAV patients. The proposed framework is openly available and applicable to any tubular structures.

Vascular distribution of stroke and its relationship to perioperative mortality and neurologic outcome after thoracic endovascular aortic repair.

OBJECTIVE: This study assessed the vascular distribution of stroke after thoracic endovascular aortic repair (TEVAR) and its relationship to perioperative death and neurologic outcome. METHODS: A retrospective review was performed for patients undergoing TEVAR between 2001 and 2010. Aortic arch hybrid and abdominal debranching cases were excluded. Demographics, operative variables, and neurologic complications were examined. Stroke was defined as any new focal or global neurologic deficit lasting>24 hours with radiographic confirmation of acute intracranial pathology. RESULTS: Perioperative stroke occurred in 20 of 530 patients (3.8%) undergoing TEVAR. The cohort was 55% male and a mean age of 75.2±8.9 years (range, 57-90 years). Among patients with perioperative strokes, the indication for surgery was degenerative aneurysm in 14 (mean diameter, 6.8 cm), acute type B dissection in four, penetrating atherosclerotic aneurysm in one, and aortic transection in one. Cases were performed urgently or as an emergency in 60%. The proximal landing zone was zone 2 in 11 or zone 3 in nine. All strokes were embolic. The vascular distribution of stroke involved the anterior cerebral (AC) circulation in eight (zone 2, n=5) and the posterior cerebral (PC) circulation in 12 (zone 2, n=6). Laterality of cerebral infarction included five right-sided, eight left-sided, and seven bilateral strokes. Nine strokes were diagnosed<24 hours after operation. There was no difference in baseline demographics, aortic pathology, acuity, zone coverage, preoperative left subclavian artery revascularization, number of stents, or estimated blood loss between stroke groups based on vascular distribution. Independent risk factors for any perioperative stroke were chronic renal insufficiency (odds ratios [OR], 4.65; 95% confidence interval [CI], 1.22-17.7; P=.02) and history of prior stroke (OR, 4.92; 95% CI, 1.69-14.4; P=.004); the risk factor for AC stroke was prior stroke (OR, 7.67; 95% CI, 1.25-46.9; P=.03) and the risk factors for PC stroke were age (OR, 1.11; 95% CI, 1.00-1.23; P=.04), prior stroke (OR, 7.53; 95% CI, 1.78-31.8; P=.006), zone 2 coverage (OR, 6.11; 95% CI, 1.15-32.3; P=.03), and penetrating atherosclerotic ulcer (OR, 32.7; 95% CI, 1.33-807.2; P=.03). Overall in-hospital mortality was 20% (n=4), with those sustaining PC strokes observed to trend toward increased mortality (33% vs 0%; P=.12). Patients with AC strokes were more likely than those with PC strokes to achieve complete recovery of neurologic deficits before discharge (75% vs 17%; P=.02). CONCLUSIONS: Perioperative stroke after TEVAR is primarily an embolic event. Although infrequent, stroke was associated with significant morbidity and death, particularly among those with strokes involving the PC circulation.

Risk factors, outcomes, and clinical manifestations of spinal cord ischemia following thoracic endovascular aortic repair.

OBJECTIVE: The purpose of this study was to assess the incidence, risk factors, and clinical manifestations of spinal cord ischemia (SCI) after thoracic endovascular aortic repair (TEVAR). METHODS: A retrospective review of a prospectively collected database was performed for all patients undergoing TEVAR at a single academic institution between July 2002 and June 2010. Preoperative demographics, procedure-related variables, and clinical details related to SCI were examined. Logistic regression analysis was performed to identify risk factors for the development of SCI. RESULTS: Of the 424 patients who underwent TEVAR during the study period, 12 patients (2.8%) developed SCI. Mean age of this cohort with SCI was 69.6 years (range, 44-84 years), and 7 were women. One-half of these patients had prior open or endovascular aortic repair. Indication for surgery was either degenerative aneurysm (n = 8) or dissection (n = 4). Six TEVARs were performed electively, with the remaining done either urgently or emergently due to contained rupture (n = 2), dissection with malperfusion (n = 2), or severe back pain (n = 2). All 12 patients underwent extent C endovascular coverage. Multivariate regression analysis demonstrated chronic renal insufficiency to be independently associated with SCI (odds ratio [OR], 4.39; 95% confidence interval [CI], 1.2-16.6; P = .029). Onset of SCI occurred at a median of 10.6 hours (range, 0-229 hours) postprocedure and was delayed in 83% (n = 10) of patients. Clinical manifestations of SCI included lower extremity paraparesis in 9 patients and paraplegia in 3 patients. At SCI onset, average mean arterial pressure (MAP) and lumbar cerebrospinal fluid (CSF) pressure was 77 mm Hg and 10 mm Hg, respectively. Therapeutic interventions increased blood pressure to a significantly higher average MAP of 99 mm Hg (P = .001) and decreased lumbar CSF pressure to a mean of 7 mm Hg (P = .30) at the time of neurologic recovery. Thirty-day mortality was 8% (1 of 12 patients). The single patient who expired, never recovered any lower extremity neurologic function. All patients surviving to discharge experienced either complete (n = 9) or incomplete (n = 2) neurologic recovery. At mean follow-up of 49 months, 7 of 9 patients currently alive continued to exhibit complete, sustained neurologic recovery. CONCLUSION: Spinal cord ischemia after TEVAR is an uncommon, but important complication. Preoperative renal insufficiency was identified as a risk factor for the development of SCI. Early detection and treatment of SCI with blood pressure augmentation alone or in combination with CSF drainage was effective in most patients, with the majority achieving complete, long-term neurologic recovery.

Does perioperative systolic blood pressure variability predict mortality after cardiac surgery? An exploratory analysis of the ECLIPSE trials.

BACKGROUND: Few studies describe an association of perioperative blood pressure stability with postoperative outcome. We tested the hypothesis that systolic blood pressure (SBP) variability in patients undergoing cardiac surgery is associated with 30-day mortality. METHODS: Perioperative blood pressure variability was evaluated in the 1512 patients who were randomized and had perioperative hypertension in the ECLIPSE trials. Blood pressure variability was assessed as the product of magnitude × duration of SBP excursions outside defined SBP ranges (area under the curve). SBP ranges were analyzed from 65 to 135 mm Hg intraoperatively and 75 to 145 mm Hg pre- or postoperatively, up to 105 to 135 mm Hg intraoperatively and 115 to 145 mm Hg pre- or postoperatively, with the narrower ranges defined by progressively increasing the lower SBP limit by 10 mm Hg increments. Multiple logistic regression was used to assess the association of blood pressure variability with 30-day mortality obtained from the primary ECLIPSE trial results. RESULTS: Increased SBP variability outside a range of 75 to 135 mm Hg intraoperatively and 85 to 145 mm Hg pre- and postoperatively is significantly associated with 30-day mortality. The odds ratio was 1.16 (95% confidence interval, 1.04-1.30) for 30-day mortality risk per incremental SBP excursion of 60 mm Hg × min/h. The predicted probability of 30-day mortality increased for low-risk patients from 0.2% to 0.5%, and for high-risk patients from 42.4% to 60.7% if the area under the curve increased from 0 to 300 mm Hg × min/h. CONCLUSIONS: Perioperative blood pressure variability is associated with 30-day mortality in cardiac surgical patients, proportionate to the extent of SBP excursions outside the range of 75 to 135 mm Hg intraoperatively and 85 to 145 mm Hg pre- and postoperatively. Predicted mortality was greater for high-risk patients than for low-risk patients.

Reversal of delayed-onset paraparesis after revision thoracic endovascular aortic repair for ruptured thoracic aortic aneurysm.

Thoracic endovascular aortic repair (TEVAR) is an important surgical option for the emergency treatment of ruptured thoracic aortic aneurysms, but is associated with a risk of spinal cord ischemia (SCI). Although risk factors for the development of SCI have been well described, the effectiveness of treatment to increase spinal cord perfusion pressure remains incompletely understood. We report the successful treatment of delayed-onset paraparesis after revision TEVAR for acute descending thoracic aortic rupture with the combined use of blood pressure augmentation and cerebrospinal fluid drainage. The clinical manifestations, pathophysiology, and management of SCI after TEVAR are reviewed.

Preoperative total lymphocyte count in peripheral blood as a predictor of poor outcome in adult cardiac surgery.

OBJECTIVE: The aim of this study was to investigate the prognostic value of the preoperative total lymphocyte count in peripheral blood as a predictor of postoperative complications and mortality in cardiac surgery. DESIGN: A retrospective, observational study. SETTING: The Novosibirsk State Research Institute of Circulation Pathology (single institution). PARTICIPANTS: All adults undergoing primary cardiopulmonary bypass in 2009. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The cohort size was 1,368 patients operated upon with cardiopulmonary bypass. Patient characteristics, hospital mortality, postoperative complications, ventilation time, intensive care unit, and hospital stay were analyzed. A preoperative total lymphocyte count <1,500 cells/µL was associated with significantly higher mortality by univariate (p < 0.0001) and multivariate (p < 0.044) analyses. A low preoperative total lymphocyte count was associated with more frequent inotropic support (p < 0.001); postoperative heart arrhythmia (p < 0.001); dialysis-dependent acute renal failure (p < 0.001); and a prolonged ventilation time (p = 0.001), intensive care unit stay (p < 0.001), and hospital stay (p = 0.007). CONCLUSIONS: A low preoperative total lymphocyte count in peripheral blood is a useful prognostic criterion for the evaluation of a complicated postoperative period in cardiac patients operated under cardiopulmonary bypass.

The Economic Consequences of Cardiac Surgery Associated Acute Renal Dysfunction After Heart Surgery.

The Society of Thoracic Surgeons definition of acute renal failure requires a 3-fold rise in creatinine, creatinine > 4 mg/dL (with at least 0.5mg/dL rise from preoperative value), or new hemodialysis requirement. This definition does not capture the incidence, clinical impact, and economic burden of lesser degrees of acute renal dysfunction. A retrospective cohort study using discharge data from 650 hospitals was extracted from the Premier administrative database (2010-2014) for index cardiac cases (isolated coronary artery bypass grafting, isolated valve, and coronary artery bypass grafting-valve). We documented acute renal dysfunction through International Classification of Diseases (ICD) 9-CM codes and hospital charges, excluding those patients with pre-existing renal dysfunction. The incidence, length of stay , and total hospital costs associated with renal dysfunction for each of the index procedures were captured. The results reported are unadjusted for demographic and clinical factors. A total of 200,471 procedures were available for analysis in the database. The mean age was 66 years, 68.2% were male and 74% were white. Based on ICD 9-CM codes and hospital charges for these cases, 27,216 (13.6%) patients had some level of renal dysfunction. In addition to increase in length of stay, patients who developed renal dysfunction had an associated 57-85% increase in total cost of hospitalization. The incidence of renal dysfunction in this study is higher than reported previously. The Society of Thoracic Surgeons definition of renal failure captures only severe disease and may miss lesser degrees of dysfunction, which nonetheless have an impact on patient outcome and costs.