Andreas R. de Biasi

Science for surgeons: Understanding pump thrombogenesis in continuous-flow left ventricular assist devices

Left ventricular assist devices (LVADs) have emerged as a mainstay, lifesaving treatment option for patients with refractory heart failure, with 1and 2-year actuarial survival rates of 80% and 70%, respectively, for the current generation of Food and Drug Administration-approved continuous-flow devices. Despite this progress, continuousflow LVADs are not without their shortcomings. One issue in particular continues to vex these devices and is increasingly garnering attention in the literature: Device thrombosis and its attendant thromboembolic complications. After a recent article exposed an unexpected uptick in the incidence of pump thrombosis with 1 of the 2 approved durable continuous-flow pumps, a flurry of studies quickly ensued that sought to better delineate the problem of LVAD thrombogenesis. Much of this effort focuses on developing patient-level and/or device-specific predictors of thrombus formation as clotting is not inevitable with current devices. The results of such clinical endeavors will no doubt bevital to improving outcomes; however, what is often lost in these analyses is an understanding of the thrombus itself. Simple questions like, ‘‘What exactly is a thrombus?’’ are often taken for granted, yet, overcoming the multifactorial scourge of LVAD thrombosis demands that we understand the answers to these fundamental questions. We therefore present a contemporary review of the basic science of thrombogenesis in the setting of LVAD support and begin by outlining how clots typically form in devices, incorporating new insights into established clotting cascades. Then, we invoke a Virchow’s triad of sorts to explain the 3 fundamental determinants of pump thrombogenesis: (1) titanium’s bioreactive surface acts as a nidus for

Outcomes of Open Repair of Mycotic Descending Thoracic and Thoracoabdominal Aortic Aneurysms

BACKGROUND The purpose of this study was to evaluate the short- and intermediate-term outcomes of open repair of mycotic thoracic and thoracoabdominal aneurysms. Contemporary surgical and perioperative techniques were utilized. METHODS From November 1997 to May 2014, 14 consecutive patients underwent open repair of descending thoracic (n = 9, 64.3%) and thoracoabdominal (n = 5, 35.7%) mycotic aortic aneurysms. All procedures were performed through the left side of the chest. Infected tissue was completely debrided and excised. Aortic continuity was restored in situ with a Dacron prosthesis (Macquet Corp, Oakland, NJ). Soft tissue coverage of the prosthesis was performed when anatomy and patient condition permitted. Perioperative outcomes, intermediate-term survival, and reinfection rates were examined. RESULTS All patients presented with either aneurysm-related symptoms or a clinical picture of sepsis. Diagnosis was confirmed utilizing computed tomography imaging. Mean age was 66 ± 13 years, 8 patients (57.1%) were male, and mean aneurysm size was 5.9 ± 1.3 cm. All patients were hypertensive, 3 (21.4%) had prior coronary revascularization, 7 (50%) had chronic pulmonary disease, 5 (35.7%) had diabetes mellitus, and 2 (14.3%) had end-stage renal disease requiring dialysis. Twelve patients (85.7%) had aneurysm-related pain, and 9 (64.3%) of them had contained rupture. Mean time from onset of illness to surgery was 36 days (range, 0 to 153). On preoperative blood cultures, 4 (28.6%) grew Staphylococcus aureus, 4 (28.6%) grew gram negative organisms, 2 (14.3%) grew mycobacterium, and 4 cultures (28.6%) had negative results. Empiric broad-spectrum antibiotics were initiated on all patients and adjusted based on final cultures. A majority of patients underwent repair utilizing a clamp-and-sew technique (n = 10, 71.4%); the remainder (n = 4, 28.6%) required repair under profound hypothermic circulatory arrest. After radical debridement of the infected tissue, grafts were placed in the normal anatomic position; 6 (42.9%) patients had additional soft tissue coverage, 5 (35.7%) utilizing an omental flap and 1 (7.1%), a serratus muscle flap. There was 1 in-hospital death (7.1%) secondary to ischemic bowel. Four patients (28.6%) required tracheostomy, and 1 (7.1%) had recurrent nerve injury. None of the patients incurred spinal cord injury, stroke, or new onset renal failure requiring dialysis. After surgery, all patients were given 6 weeks of intravenous antibiotics. Lifelong suppression therapy was maintained with oral antibiotics. There were no episodes of prosthetic graft infection on follow-up. Univariate analysis revealed that New York Heart Association functional class, diabetes, and preoperative renal dysfunction were preoperative risk factors for major adverse events. Mean follow-up time was 26.5 months (median 8.2; range, 1 to 142). Actuarial 5-year survival was 71%. CONCLUSIONS Open repair of mycotic descending thoracic and thoracoabdominal aortic aneurysms remains the gold standard of therapy. Aggressive intraoperative debridement with in situ prosthetic reconstruction permits a high rate of success in this very high risk cohort of patients. Lifelong antibiotic suppression therapy may prevent late prosthetic graft infection.

Reoperative ''valve-in-valve'' transapical transcatheter mitral valve replacement in a high-risk patient with a recent transapical transcatheter aortic valve replacement and a degenerated bioprosthetic mitral valve

Transapical transcatheter aortic valve replacement (TAAVR) can safely be performed in high-risk patients who are not candidates for conventional replacement. However, using the transapical transcatheter (TA) approach as a reoperative strategy in patients who have undergone previous TA valve surgery has not been well described. We therefore report the first known case of a patient who recently underwent TA-AVR and subsequently developed severe prosthetic mitral regurgitation that was managed with a ‘‘valve-invalve’’ TA mitral valve (MV) replacement.

National Analysis of Short-Term Outcomes and Volume-Outcome Relationships for Transcatheter Aortic Valve Replacement in the Era of Commercialization.

Objectives: We queried the 2012 National Inpatient Sample in order to (1) further describe the short-term outcomes for transcatheter aortic valve replacement (TAVR) and (2) characterize possible volume-outcome relationships and other prognostic factors for this procedure. Methods: Demographics and inhospital outcomes were tabulated for all patients, as were hospital characteristics and procedural-volume data for all centers at which patients underwent TAVR. Logistic regression analyses were performed to identify independent risk factors for mortality or morbidity. Results: 7,635 patients aged ≥18 years received TAVR during the study period; 84.5% (n = 6,450) underwent transfemoral TAVR and the rest were treated transapically. The median age was 83 years (IQR 77-88 years) and cardiovascular comorbidities were widespread. Overall inhospital mortality was 5.0% (n = 380), and 1.4% (n = 105) of the patients experienced a stroke. All-cause procedure-related morbidity was 24.7% (n = 1,885). Annual hospital TAVR volume did not predict inhospital mortality or morbidity (OR 1.00, 95% CI 0.99-1.00, p = 0.111 and OR 1.00, 95% CI 0.99-1.00, p = 0.947, respectively). Conclusions: Our analysis helps to confirm the short-term safety profile of TAVR and further demonstrates that inhospital outcomes have remained acceptable as this procedure has become commercialized.

Transapical mitral valve-in-valve implantation for patients in cardiogenic shock.

Transcatheter aortic valve implantation has demonstrated excellent results in high risk and inoperable patients, and been extended to valve-in-valve implantation for those with prosthetic aortic and, more recently, mitral valve failure. Despite its use in high risk and inoperable patients, active cardiogenic shock has historically been considered a contraindication. We describe 2 patients in acute cardiogenic shock from prosthetic mitral valve failure treated with transcatheter mitral valve-in-valve implantation. Transcatheter mitral valve therapies should be considered in patients in cardiogenic shock from prosthetic mitral valve failure, although, larger studies are needed to make any strong recommendation.

Common Cause of Mortality in Trauma but Manageable Nonetheless.

Information about a real patient is presented in stages (boldface type) to expert clinicians (Drs Eachempati and Salemi), who respond to the information, sharing their reasoning with the reader (regular type). A discussion by the authors follows. An obese but otherwise healthy 53-year-old man was unloading a delivery van when he was struck from behind by a slow-moving garbage truck, pinning him between the 2 vehicles. The patient was lying supine on the ground when emergency medical services arrived. He was alert and oriented with a Glasgow Coma Scale score of 15. The patient was complaining of pain in his right upper extremity and numbness in his left foot. His initial vital signs were notable for a heart rate of 100 bpm; his blood pressure was 150/90 mm Hg; and his breathing was elevated at 22 breaths per minutes. The patient denied loss of consciousness and had no neck, back, or chest pain. Per emergency medical services, the patient’s midchest appeared erythematous and his left lung field was coarse on auscultation, and he had a small abrasion on his left knee. The rest of his in-the-field examination was unremarkable. A cervical collar was placed, and the patient was placed on a back-board for transport. The patient’s vital signs remained stable en route per the emergency medical services’ report, although he became increasingly anxious and repeatedly removed both his cervical collar and a nonrebreather mask that had been placed empirically. On arrival in our trauma bay, the patient was found to be in shock: pulse rate, 129 bpm; blood pressure, 69/51 mm Hg; respiratory rate, 20 breaths per minute; and O 2 saturation, 80% on room air. He remained awake with a Glasgow Coma Scale score of 15 but now was complaining of difficulty breathing and of right-sided chest and back pain. His …

Aortic Angulation Does Not Impact Outcomes in Self-Expandable or Balloon-Expandable Transcatheter Aortic Valve Replacement

Objectives: The role of aortic angulation in attenuating procedural success in balloon-expandable (BE) and self-expandable (SE) transcatheter aortic valve replacement (TAVR) has been controversial. Methods: We retrospectively assessed patients undergoing SE and BE TAVR who had an aortic angle measured on multidetector computed tomography at a single tertiary referral center. The primary outcome was device success, measured per the Valve Academic Research Consortium-2 criteria. Clinical outcomes at 30 days (including mortality) were also assessed. Results: A total of 251 patients were identified; 182 patients received a BE valve and 69 patients an SE valve. The median aortic angle was 46.8° (range 24.4–70°) in the BE group and 43.3° (range 20–71°) in the SE group. In multivariate logistic regression analysis, aortic angulation did not affect device success. Mortality at 30 days and 12 months and postprocedural clinical outcomes were similarly not associated with aortic angulation. Conclusion: In this cohort of patients undergoing BE and SE TAVR over a wide range of aortic angles, we found no associations between angle and device success or any other clinical metrics. Increased aortic angulation does not adversely affect outcomes in BE or SE TAVR.

Systemic blood pressure trends and antihypertensive utilization following continuous-flow left ventricular assist device implantation: an analysis of the interagency registry for mechanically assisted circulatory support

Background Elevated systemic blood pressure (SBP) has been linked to complications in Continuous-flow left ventricular assist devices (CF-LVADs), including stroke and pump thrombosis. We queried Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) to describe the response of SBP to CF-LVAD implantation and to delineate contemporary trends in antihypertensive (AH) utilization for patients with these pumps. Methods We identified all CF-LVAD implantations in patients older than 18 years from 2006-2014, excluding those whose durations were less than 30 days. Pre-implant patient demographics and characteristics were obtained for each record. SBPs [i.e., mean arterial pressures (MAPs)], AH-use data, and vital status were tabulated, extending up to 5 years following implantation. Results A total of 10,329 CF-LVAD implantations were included for study. Post-implant, SBPs increased rapidly during the first 3 months but plateaued thereafter; AH utilization mirrored this trend. By 6 months, mean MAPs climbed 12.2% from 77.6 mmHg (95% CI: 77.4-77.8) pre-implantation to 87.1 mmHg (95% CI: 86.7-87.4) and patients required a mean of 1.8 AH medications (95% CI: 1.75-1.78) -a 125% increase from AH use at 1-week post-implantation (0.8 AHs/patient, 95% CI: 0.81-0.83) but a 5.3% decrease from pre-implant utilization (1.9 AHs/patient, 95% CI: 1.90-1.92). Once medication changes stabilized, the most common AH regimens were lone beta blockade (15%, n=720) and a beta blocker plus an ACE inhibitor (14%, n=672). Conclusions SBP rises rapidly after CF-LVAD implantation, stabilizing after 3 months, and is matched by concomitant changes in AH utilization; this AH use has increased over consecutive implant years.

National Analysis of Short-Term Outcomes After Pulmonary Resections on Cardiopulmonary Bypass

BACKGROUND Pulmonary resections using cardiopulmonary bypass (CPB) are infrequently performed. Their short-term outcomes are not well described. We queried the National Inpatient Sample over a 10-year period (2001 to 2011) to more clearly delineate the short-term outcomes of patients undergoing pulmonary resections on CPB. METHODS We identified all patients 18 years and older who underwent pulmonary lobectomy (LB) or pneumonectomy (PN) on CPB; lung transplantations were excluded. We then grouped these patients based on the setting in which bypass was used: LB/PN with planned CPB (group 1), LB/PN with concomitant on-pump cardiac procedure (group 2), or LB/PN requiring CPB secondary to injury (group 3). Demographic data and inhospital outcomes were obtained for each patient. RESULTS In all, 843 patients underwent LB or PN on CPB during the study period. Lobectomies were the most commonly performed procedure overall. Inhospital mortality for groups 1, 2, and 3 were 22% (n = 58), 16% (n = 61), and 57% (n = 115), respectively. Complications were prevalent across all groups. Routine discharge was achieved by fewer than half of all patients: 48% of group 1 (n = 128); 34% of group 2 (n = 129); and 18% of group 3 (n = 36). Pneumonectomy (odds ratio 2.74, 95% confidence interval: 1.00 to 7.53, p = 0.049) as well as using CPB either as part of a combined cardiac surgery (odds ratio 1.48, 95% confidence interval: 0.39 to 5.59, p = 0.002) or because of injury (odds ratio 6.52, 95% confidence interval: 2.13 to 19.99, p = 0.002) were found to be significant multivariate predictors of short-term mortality. CONCLUSIONS Pulmonary resections on CPB carry considerable short-term mortality and morbidity, but some risk can be partially mitigated when bypass is planned preoperatively.