Stephen H. McKellar

Ministernotomy versus conventional sternotomy for aortic valve replacement: A systematic review and meta-analysis

OBJECTIVE Most aortic valve replacements are by conventional full median sternotomy. Less invasive approaches have been developed with partial upper sternotomy (ministernotomy). METHODS Systematic review and meta-analysis were performed with studies comparing ministernotomy and full sternotomy for aortic valve replacement. RESULTS Twenty-six studies were selected, with 4586 patients with aortic valve replacement (2054 ministernotomy, 2532 full sternotomy). There was no difference in mortality (odds ratio 0.71, 95% confidence interval 0.49-1.02). Ministernotomy had longer crossclamp and bypass times (weighted mean difference 7.90 minutes, 95% confidence interval 3.50-10.29 minutes, and 11.46 minutes, 95% confidence interval 5.26-17.65 minutes, respectively). Both intensive care unit and hospital stays were shorter with ministernotomy (weighted mean difference -0.46 days, 95% confidence interval -0.72 to -0.20 days, and -0.91 days, 95% confidence interval -1.45 to -0.37 days, respectively). Ministernotomy had shorter ventilation time and less blood loss within 24 hours (weighted mean difference -2.1 hours, 95% confidence interval -2.95 to -1.30 hours, and -79 mL, 95% confidence interval -23 to 136 mL, respectively). Randomized studies tended to demonstrate no difference between ministernotomy and full sternotomy. Rate of conversion from partial to conventional sternotomy was 3.0% (95% confidence interval 1.8%-.4%). CONCLUSION Ministernotomy can be performed safely for aortic valve replacement, without increased risk of death or other major complication; however, few objective advantages have been shown. Surgeons must conduct well-designed, prospective studies of relevant, consistent clinical outcomes to determine the role of ministernotomy in cardiac surgery.

Comparison of coronary revascularization procedures in octogenarians: a systematic review and meta-analysis

Background Elderly patients are the fastest growing population in the US healthcare system and more patients aged 80 years and older require CABG or percutaneous coronary intervention (PCI) for coronary revascularization than ever before. Because octogenarian patients have not been adequately represented in randomized trials comparing CABG and PCI, the most appropriate method of revascularization for this group of patients has not been determined.Methods We performed a systematic review and a meta-analysis of 66 studies of coronary revascularization in patients aged over 80 years. The primary endpoints included 30 day mortality and long-term survival. Subgroup analyses stratified by revascularization type (PCI versus CABG) were also performed.Results Pooled estimate of 30 day mortality was 6.3% (95% CI 5.3%–7.5%), and for survival at 1, 3 and 5 years, 86% (84%–88%), 78% (74%–81%) and 67% (61%–72%), respectively. A greater number of men (P <0.001) and patients with multivessel disease (P = 0.004) were treated with CABG than with PCI. Pooled estimates, based on type of revascularization, of 30 day mortality and 1 year survival were similar (7.3% [6.3%–8.2%] for CABG vs 5.4% [4.4%–6.4%] for PCI and 86% [83%–88%] for CABG vs 87% [84%–91%] for PCI, respectively).Conclusions Available data indicate that revascularization can be performed in octogenarians with acceptable short-term and long-term outcomes; most of the evidence is, however, low level. Furthermore, it is unclear whether octogenarians derive greater survival benefit from CABG or from PCI because preprocedural risk profiles differ between intervention types. Periprocedural and long-term outcomes are, however, equivalent, and randomized, controlled trials of high-risk octogenarians are needed.

Long-Term Risk of Aortic Events Following Aortic Valve Replacement in Patients With Bicuspid Aortic Valves

Bicuspid aortic valve (BAV) is associated with ascending aortopathy predisposing to aneurysmal dilatation and dissection, even after successful aortic valve replacement (AVR). There is, however, scant evidence on which to make recommendations for prophylactic replacement of the ascending aorta at the time of AVR. The medical records of patients who underwent AVR for BAV without aortic replacement or repair from 1960 to 1995 were reviewed. Follow-up was by review of the medical record and postal questionnaire. Among 1,286 patients, the mean age at operation was 58 ± 14 years. During the follow-up interval (median 12 years, range 0 to 38), there were 13 documented aortic dissections (1%), 11 ascending aortic replacements (0.9%), and 127 documented cases of progressive aortic enlargement (9.9%). Fifteen-year freedom from aortic dissection, enlargement, or replacement was 89% (95% confidence interval [CI] 87% to 91%) and was lower in patients with documented aortic enlargement at the time of AVR (85%, 95% CI 81% to 89%) compared to those whose aortic dimensions were normal (93%, 95% CI 90% to 96%) (p = 0.001). Multivariate predictors of aortic complications included interval (subsequent) AVR (hazard ratio [HR] 3.5, 95% CI 2.3 to 5.4, p <0.001), concomitant coronary artery bypass grafting (HR 2.6, 95% CI 1.7 to 4.0, p <0.001), enlarged aorta (HR 1.8, 95% CI 1.3 to 2.6, p = 0.001), and history of tobacco abuse (HR 1.8, 95% CI 1.2 to 2.6, p = 0.003). Aortic dilatation did not predict mortality. In conclusion, despite a true risk for aortic events after AVR for BAV, the occurrence of aortic dissection was low. Any incremental surgical risk imposed by prophylactic replacement of the ascending aorta must be equally low.

Frequency of Cardiovascular Events in Women With a Congenitally Bicuspid Aortic Valve in a Single Community and Effect of Pregnancy on Events

Pregnancy and congenitally bicuspid aortic valve (BAV) are thought to be risk factors for aortic dissection; however, the population-based risk for patients with the 2 risk factors remains unknown. We investigated the relation between pregnancy and ascending aortic events in women with congenital BAV living in Olmsted County, Minnesota. Our institutional echocardiographic database was searched for women residing in Olmsted County with congenital BAV diagnosed from 1980 to 1999. We reviewed medical records for end points of aortic events (dilatation, dissection, or surgery) and aortic valve replacement (AVR). Obstetric history and further outcome follow-up were collected by postal survey. We identified 88 women with BAV. Median age at diagnosis was 35 years. Obstetric history totaled 216 pregnancies and 186 deliveries. There were no aortic dissections. During follow-up (median 12.3 years), 24 patients underwent AVR (n = 14), ascending aortic surgery (n = 3), or AVR and ascending aortic surgery (n = 7). Pregnancy was not associated with dilatation of the aorta, aorta surgery, or AVR. At echocardiographic diagnosis of BAV, 5 patients (6%) had aortas >40 mm in greatest diameter and 1 patient has >50 mm. Of 60 patients with serial echocardiograms for comparison (median interval 10.7 years), 21 patients (35%) had aortas measuring >40 mm in greatest dimension and 2 patients had >50 mm. In conclusion, aortic dissection in women with BAV and pregnancy is rare in the community. There is a significant rate of progressive enlargement of the aorta, warranting longitudinal follow-up.

Choice of Hemostatic Agent Influences Adhesion Formation in a Rat Cecal Adhesion Model

INTRODUCTION Hemostatic agents are frequently used during abdominal surgery and some are linked to adhesion formation. We sought to evaluate the impact of several commonly used hemostatic agents on adhesion formation in a rat peritoneal model. METHODS In our study, Wister outbred rats underwent laparotomy and excision of a portion of their peritoneum to initiate adhesion formation process. One of six different hemostatic agents, namely, activated starch microspheres (Arista AH; Medafor Inc., Minneapolis, MN), glutaraldehyde activated collagen (BioGlue; Cryolife Inc., Kennesaw, GA), thrombin coated collagen microspheres (FloSeal; Baxter Inc., Deerfield, IL), thrombin activated fibrin polymer (Tisseel, Baxter), polyethylene glycol polymer (CoSeal, Baxter), or oxidized cellulose (Surgicel; Ethicon Inc., Somerville, NJ), was placed in the area of peritoneal defect. All animals were sacrificed on post-op day 7 and strength and extent of adhesion formation was determined. Histopathological examination of rat caecum was also performed. RESULTS Arista and CoSeal showed significantly lower adhesion formation than controls (P < 0.05). Higher adhesion scores were seen in BioGlue (P < 0.05) treated rats. Additionally, histopathologic examination showed that BioGlue caused statistically more inflammation and necrosis than controls (P < 0.05). Total adhesion score increased with residual amount of agent present at 7 d. CONCLUSIONS Use of Arista and CoSeal may help in reducing peritoneal adhesions after intra-abdominal surgeries. Furthermore, there appears to be a relationship between the creation of inflammation and necrosis in tissues and the eventual formation of adhesions. This could aid in improving the design of these agents in the future.

Treatment of infected left ventricular assist device using antibiotic-impregnated beads

There is no well-established therapy for treating infections of heart-assist or artificial heart devices, a serious problem with life-threatening consequences. We used a promising new approach in which antibiotic-impregnated polymethylmethacrylate beads were placed around an implanted left ventricular assist device to control an external blood pump infection in a bridge-to-transplant patient. In this case report, we describe the potential of antimicrobial-impregnated polymethylmethacrylate beads for in situ control of infections involving external surfaces of cardiovascular devices.

Surgical treatment of tricuspid valve insufficiency promotes early reverse remodeling in patients with axial-flow left ventricular assist devices.

OBJECTIVE The HeartMate II (Thoratec Corp, Pleasanton, Calif) continuous-flow left ventricular assist device has emerged as the standard of care for patients with advanced heart failure. The objective of this study was to assess the safety and early effectiveness of concomitant tricuspid valve procedures in patients undergoing implantation of a HeartMate II device. METHODS From February 2007 to April 2010, 83 patients underwent HeartMate II left ventricular assist device implantation. Of these, 37 patients had concomitant tricuspid valve procedures (32 repairs, 5 replacements) for severe tricuspid regurgitation. The effects of a tricuspid valve procedure on tricuspid regurgitation and right ventricular remodeling were assessed comparing echocardiographic findings at baseline and 30 days after left ventricular assist device implantation. Overall survival was also compared. RESULTS Patients undergoing a concomitant tricuspid valve procedure had more tricuspid regurgitation (vena contracta, 5.6 ± 2.1 mm vs 2.9 ± 2.0 mm; P < .001), worse right ventricular dysfunction (right ventricular end-diastolic area, 33.6 ± 6.2 mm vs 31.6 ± 8.5 mm; P = .05), higher mean right atrial pressure (17.4 ± 7.1 mm Hg vs 14.9 ± 5.1 mm Hg; P = .03), and a higher Kormos score (2.6 ± 2.1 vs 1.2 ± 1.4; P = .0008) preoperatively. One month after surgery, tricuspid regurgitation was worse in patients who underwent left ventricular assist device implantation alone (+18.6%), whereas it improved significantly in patients undergoing a concomitant tricuspid valve procedure (-50.2%) (P = .005). A corresponding significant reduction in right ventricular end-diastolic area (33.6% ± 6.2% vs 30.1% ± 9.7%; P = .03) and a trend toward better right ventricular function (55.5% ± 79.7% vs 35.7% ± 60.5%; P = .28) were noted in patients undergoing a concomitant tricuspid valve procedure. Survival was comparable between the 2 groups. CONCLUSIONS In patients with severe tricuspid regurgitation undergoing left ventricular assist device implantation, a concomitant tricuspid valve procedure effectively reduces tricuspid regurgitation and promotes reverse remodeling of the right ventricle.

Evolution of general surgical problems in patients with left ventricular assist devices

BACKGROUND Left ventricular assist devices (LVADs) are increasingly used to treat patients with end-stage heart failure. These patients may develop acute noncardiac surgical problems around the time of LVAD implantation or, as survival continues to improve, chronic surgical problems as ambulatory patients remote from the LVAD implant. Previous reports of noncardiac surgical problems in LVAD patients included patients with older, first-generation devices and do not address newer, second-generation devices. We describe the frequency and management of noncardiac surgical problems encountered during LVAD support with these newer-generation devices to assist noncardiac surgeons involved in the care of patients with LVADs. METHODS We retrospectively reviewed the medical records of consecutive patients receiving LVADs at our institution. We collected data for any consultation by noncardiac surgeons within the scope of general surgery during LVAD support and subsequent treatment. RESULTS Ninety-nine patients received implantable LVADs between 2003 and 2009 (first-generation, n = 19; second-generation, n = 80). Excluding intestinal hemorrhage, general surgical opinions were rendered for 34 patients with 49 problems, mostly in the acute recovery phase after LVAD implantation. Of those, 27 patients underwent 28 operations. Respiratory failure and intra-abdominal pathologies were the most common problems addressed, and LVAD rarely precluded operation. Patients with second-generation LVADs were more likely to survive hospitalization (P = .04) and develop chronic, rather than emergent, surgical problems. CONCLUSION Patients with LVADs frequently require consultation from noncardiac surgeons within the scope of general surgeons and often require operation. Patients with second-generation LVADs are more likely to become outpatients and develop more elective surgical problems. Noncardiac surgeons will be increasingly involved in caring for patients with LVADs and should anticipate the problems unique to this patient population.

Bridge to Removal: A Paradigm Shift for Left Ventricular Assist Device Therapy

Ventricular assist devices have become standard therapy for patients with advanced heart failure either as a bridge to transplantation or destination therapy. Despite the functional and biologic evidence of reverse cardiac remodeling, few patients actually proceed to myocardial recovery, and even fewer to the point of having their device explanted. An enhanced understanding of the biology and care of the mechanically supported patient has redirected focus on the possibility of using ventricular assist devices as a bridge to myocardial recovery and removal. Herein, we review the current issues and approaches to transforming myocardial recovery to a practical reality.

Practice characteristics of Emergency Department extracorporeal cardiopulmonary resuscitation (eCPR) programs in the United States: The current state of the art of Emergency Department extracorporeal membrane oxygenation (ED ECMO).

PURPOSE To characterize the current scope and practices of centers performing extracorporeal cardiopulmonary resuscitation (eCPR) on the undifferentiated patient with cardiac arrest in the emergency department. METHODS We contacted all US centers in January 2016 that had submitted adult eCPR cases to the Extracorporeal Life Support Organization (ELSO) registry and surveyed them, querying for programs that had performed eCPR in the Emergency Department (ED ECMO). Our objective was to characterize the following domains of ED ECMO practice: program characteristics, patient selection, devices and techniques, and personnel. RESULTS Among 99 centers queried, 70 responded. Among these, 36 centers performed ED ECMO. Nearly 93% of programs are based at academic/teaching hospitals. 65% of programs are less than 5 years old, and 60% of programs perform ≤3 cases per year. Most programs (90%) had inpatient eCPR or salvage ECMO programs prior to starting ED ECMO programs. The majority of programs do not have formal inclusion and exclusion criteria. Most programs preferentially obtain vascular access via the percutaneous route (70%) and many (40%) use mechanical CPR during cannulation. The most commonly used console is the Maquet Rotaflow(®). Cannulation is most often performed by cardiothoracic (CT) surgery, and nearly all programs (>85%) involve CT surgeons, perfusionists, and pharmacists. CONCLUSIONS Over a third of centers that submitted adult eCPR cases to ELSO have performed ED ECMO. These programs are largely based at academic hospitals, new, and have low volumes. They do not have many formal inclusion or exclusion criteria, and devices and techniques are variable.