Surgical Approaches for Pericardial Diseases: What Is New?

PURPOSE OF REVIEW: The purpose of this review is to discuss the evolving techniques and approaches for pericardiectomy, with a focus on the use of cardiopulmonary bypass (CPB) and the extent of radical pericardial resection. The review aims to highlight the benefits and considerations associated with these modifications in radical pericardiectomy. RECENT FINDINGS: Recent studies have demonstrated that the use of CPB during pericardiectomy does not increase procedural risk or negatively impact survival. In fact, it has been shown to contribute to a more radical resection and improve postoperative outcomes, which is associated with less recurrence and better survival. The review emphasizes the importance of radical pericardiectomy and the use of CPB in achieving successful outcomes. Radical resection of the pericardium, facilitated by CPB, helps minimize the risk of recurrent constrictions and the need for reinterventions. The findings highlight the correlation between postoperative outcomes and survival, further supporting the use of CPB.

Modified Ravitch Procedure for Pectus Excavatum Combined With Complex Cardiac Surgery.

Pectus excavatum is common in patients with connective tissue disorders or congenital heart disease undergoing cardiac surgery, and is occasionally severe enough to warrant repair. The optimal surgical strategy is currently debated. We report our experience with simultaneous repair. From January 2012 to January 2020, 11 patients (median age of 35 ± 18 years, range 12-74) underwent a modified Ravitch procedure for severe pectus excavatum performed by a single thoracic surgeon at the time of simultaneous complex cardiac surgery. Eight patients (73%) had a confirmed connective tissue disorder and 2 patients (18%) had recurrent pectus excavatum following a failed Nuss procedure in adolescence. The mean Haller index was 7.3 ± 3.2 (range 3.8-13). The most common concomitant cardiac procedures were valve-preserving aortic root replacement (n=7, 64%) and mitral valve repair (n = 4, 36%). Patients are presented as a case series with descriptive analysis. The median total operative and cardiopulmonary bypass times were 400 minutes (±109 minutes) and 168 minutes (± 43 minutes), respectively. No deaths occurred in-hospital or during follow-up. There were no reoperations for bleeding, tamponade or other indications. No deep or superficial sternal wound infections occurred. Postoperative analgesia regimens were multimodal to facilitate early mobilization and pulmonary hygiene. None of the patients required prolonged ventilation or reintubation for respiratory failure. The mean stay in the intensive care unit was 82 hours (±56 hours) and the mean hospital stay was 9.1 days (2.4 days). Concurrent pectus excavatum repair at the time of cardiac surgery using a modified Ravitch technique can be safely performed by a multi-disciplinary team and should be considered for patients with multiple indications for operation.

The current era of left ventricular assist devices.

Left ventricular assist devices (LVADs) have changed the landscape of treatment options for patients with end stage heart failure. Due to the limited availability of donor hearts for transplantation, LVADs have become an important option for many of these patients. Much progress has been made in the device industry since then, and newer devices continue to improve patient outcomes. In this review, we will discuss some of the key transitions in LVADs over the years, the current LVADs used in practice today, implantation techniques, the impact of the new heart allocation system on LVAD use and future prospective LVADs.

Serious Gastrointestinal Complications After Cardiac Surgery and Associated Mortality.

BACKGROUND: Severe gastrointestinal (GI) complications (GICs) after cardiac surgery are associated with poor outcomes. Herein, we characterize the severe forms of GICs and associated risk factors of mortality. METHODS: We retrospectively analyzed the clinically significant postoperative GICs after cardiac surgical procedures performed at our institution from January 2010 to April 2017. Multivariable analysis was used to identify predictors for in-hospital mortality. RESULTS: Of 29,909 cardiac surgical procedures, GICs occurred in 1037 patients (3.5% incidence), with overall in-hospital mortality of 14% compared with 1.6% in those without GICs. GICs were encountered in older patients with multiple comorbidities who underwent complex prolonged procedures. The most lethal GICs were mesenteric ischemia (n = 104), hepatopancreatobiliary (HPB) dysfunction (n = 139), and GI bleeding (n = 259), with mortality rates of 45%, 27%, and 17%, respectively. In the mesenteric ischemia subset, coronary artery disease (odds ratio [OR], 4.57; P = .002], coronary bypass grafting (OR, 6.50; P = .005), reoperation for bleeding/tamponade (OR, 12.07; P = .01), and vasopressin use (OR, 11.27; P < .001) were predictors of in-hospital mortality. In the HPB complications subset, hepatic complications occurred in 101 patients (73%), pancreatitis in 38 (27%), and biliary disease in 31 (22%). GI bleeding occurred in 20 patients (31%) with HPB dysfunction. In the GI bleeding subset, HPB disease (OR, 10.99; P < .001) and bivalirudin therapy (OR, 12.84; P = .01) were predictors for in-hospital mortality. CONCLUSIONS: Although relatively uncommon, severe forms of GICs are associated with high mortality. Early recognition and aggressive treatment are mandatory to improve outcomes.

Pulmonary valve replacement in primary repair of tetralogy of Fallot in adult patients.

BACKGROUND: Adults with unrepaired tetralogy of Fallot (ToF) are common in developing countries. Long-term overload of the right ventricle places adult patients at risk for postoperative right heart failure after primary repair, which contributes to morbidity and mortality. The effect of pulmonary valve replacement (PVR) in reducing postoperative morbidity and mortality in adults has never been validated. METHODS: We conducted a retrospective cohort study in adults (age ≥18 years) with ToF undergoing primary repair from January 2014 to December 2019 at our institution. Patients were divided into three groups according to techniques used to enlarge the right ventricle outflow tract (RVOT). Baseline variables and perioperative outcomes were collected. The primary endpoint was operative mortality. Secondary endpoints were incidences of right heart failure and stage 3 acute kidney injury (AKI). RESULTS: A total of 56 patients were enrolled (mean age 41.5±11.7 years, 30 females, 53.6%). They were divided into three groups designated as the following: TA-PVR group for trans-annular patch enlargement with PVR; TA group for trans-annulus patch enlargement without PVR; and group AP for annulus preservation. Four patients (7.1%) died postoperatively, all due to right heart failure. All twelve patients in the TA-PVR group survived. There was no significant difference in mortalities among groups. Ten patients (17.9%) developed right heart failure after surgery with no significant difference among groups. Three patients (5.4%) developed stage 3 AKI after surgery, none belonging to the TA-PVR group, however, not statistically significant. CONCLUSIONS: Right heart failure is a common complication after primary repair of adult ToF. Trans-annulus patch enlargement should be cautiously selected in this population. PVR with trans-annulus patch enlargement may be a promising technique to protect against postoperative right heart failure and mortality when annulus preservation is not feasible.

Comparison of mechanical cardiopulmonary support strategies during lung transplantation.

INTRODUCTION: Lung transplantation outcomes are influenced by the intraoperative mechanical cardiopulmonary support strategy used. This surgery was historically done either on cardiopulmonary bypass (CPB) or off pump. Recently, there has been increased interest in intraoperative support with veno-arterial (VA) or veno-venous (VV) extracorporeal membrane oxygenation (ECMO). However, there is a lack of consensus on the relative risks, benefits and indications for each intraoperative support strategy. AREAS COVERED: This review includes information from cohort studies, case-control studies, and case series that compare morbidity and/or mortality of two or more intraoperative cardiopulmonary support strategies during lung transplantation. EXPERT OPINION: The optimal strategy for intraoperative cardiopulmonary support during lung transplantation remains an area of debate. Current data suggest that off pump is associated with better outcomes and could be considered whenever feasible. ECMO is generally associated with preferable outcomes to CPB, but the data supporting this association is not robust. Interestingly, whether CPB is unplanned or prolonged might influence outcomes more than the use of CPB itself. These observations can help guide surgical teams in their approach for intraoperative mechanical support strategy during lung transplantation and should serve as the basis for further investigations.

Quantifying the learning curve of emergent total arch replacement in acute type A aortic dissection.

BACKGROUND: Acute type A aortic dissection with arch involvement is a life-threatening condition, which requires immediate surgical attention. Emergent total arch replacement and root reconstruction is a technically demanding operation with varying outcomes based on surgeon experience. The human factors in total arch replacement in the emergent setting have never been systematically investigated. The ability of surgeons with low volumes to achieve acceptable results in their start-up period is not known. METHODS: From January 2013 to December 2016, patients with acute type A aortic dissection who underwent emergent total arch replacement with three surgeons were enrolled. Basic characteristics, procedural and postoperative outcomes were collected. The time of critical surgical steps and operative mortality were calculated using descriptive statistics and cumulative SUM (CUSUM) analysis. RESULTS: A total of 300 patients (age 53.8±11.5 years, female 63, 21.0%) with acute type A aortic dissection underwent emergent total arch replacement. A total of 219 patients (73.0%) had root reinforcement, 295 patients (98.3%) underwent frozen elephant trunk repair. Mean circulatory arrest and cross-clamp times were 29.8±9.8 and 112.3±32.1 min, respectively. The operative mortality was 6.7%, the stroke rate was 4.0%. The mean length of postoperative ICU and hospital stays were 8.4±10.6 and 18.0±12.2 days, respectively. By CUSUM depictions, surgeons appeared to have different learning curves with regards to operative time. By CUSUM failure analysis on operative mortality, two newly appointed surgeons in their start-up period stayed in an acceptable range, while one senior surgeon with higher volumes experienced superior outcomes and better performance. CONCLUSIONS: Although emergent total arch replacement for acute type A dissection is a complex scenario, surgeons well-trained in adult cardiac surgery are able to achieve acceptable results in their start-up period.

Prothrombin Complex Concentrate Reduces Blood Product Utilization in Heart Transplantation.

BACKGROUND: Current practices for the reversal of warfarin before cardiac surgery include the use of vitamin K and fresh frozen plasma (FFP) to reduce the risk of bleeding. Although the 2010 International Society of Heart and Lung Transplantation guidelines acknowledge the use of prothrombin complex concentrate (PCC), there is no clear consensus on its efficacy. The objective of this study was to assess the efficacy of four-factor (4-F) PCC administration in patients requiring warfarin reversal before heart transplantation by determining blood product utilization perioperatively. METHODS: Twenty-one patients who received 4-F PCC for warfarin reversal before heart transplantation were compared to a similar cohort of 39 patients who did not receive 4-F PCC, from January 2011 to July 2015. Blood product utilization was collected retrospectively for the 24-hour preoperative, intraoperative, and 48-hour postoperative periods. RESULTS: Patients receiving 4-F PCC required fewer blood products in all three time periods. In the 24-hour preoperative period, 22 (56%) patients in the control group and 2 (10%) patients in the 4-F PCC groups received blood products (p<0.001). Intraoperatively, all patients received blood products. The 4-F PCC group required fewer units of packed red blood cells (median 3 vs 7 units, p<0.001) and FFP (median 4 vs 9 units, p<0.001). In the 48-hour postoperative period, 20 (51%) patients in the control group and 5 (24%) patients in the 4-F PCC group received blood products (p=0.04). CONCLUSIONS: 4-F PCC is associated with reduced blood product utilization 24 hours preoperatively and intraoperatively. Historically, the majority of patients require FFP for warfarin reversal preoperatively. In this single-center study, a significant reduction in the need for FFP was demonstrated with the use of 4-F PCC.

A contemporary analysis of pulmonary hypertension in patients undergoing mitral valve surgery: Is this a risk factor?

OBJECTIVE: Pulmonary hypertension (PHT) has been considered a risk factor for mortality in cardiac surgery. Among mitral valve surgery (MVS) patients, we sought to determine if severe PHT increases mortality risk and if patients who undergo concomitant tricuspid valve surgery (TVS) incur additional risk. METHODS: Preoperative PHT was assessed in 1571 patients undergoing MVS, from 2004 to 2013. Patients were stratified into PHT groups as follows (mm Hg): none (<35); moderate (35-49); severe (50-79); and extreme (≥80). Propensity-score matching resulted in a total of 430 patients, by PHT groups, and 384 patients, by TVS groups. RESULTS: Patients with severe PHT had higher mortality, both 30-day (4% PHT vs 1% no PHT, P < .02) and late (defined as survival at 5 years): 75.5% severe versus 91.9% no PHT (P < .001). In propensity-score-matched groups, severe PHT was not a risk factor for 30-day (3% each, P = 1.0) or late mortality (86.2% severe vs 87.1% no PHT; P = .87). TVS did not increase 30-day (4.7% TVS vs 4.2% no TVS, P = .8) or late mortality (78.7% TVS vs 75.3% no TVS, P = .90). Late survival was lower in extreme PHT (75.4% vs no PHT 91.5%, P = .007), and a trend was found in 30-day mortality (11% extreme vs 3% no PHT, P = .16). CONCLUSIONS: Mortality in MVS is unaffected by severe PHT or the addition of TVS, yet extreme PHT remains a risk factor. Severe PHT (50-79 mm Hg) should not preclude surgery; concomitant TVS does not increase mortality.

Insulin therapy for pre-hyperglycemic beta-cell endoplasmic reticulum crowding.

Insulin therapy improves ß-cell function in early stages of diabetes by mechanisms that may exceed alleviation of glucotoxicity. In advance type 2 diabetes, hyperglycemia causes ß-cell damage and ultimately ß-cell loss. At such an advanced stage, therapeutic modalities are often inadequate. Growing evidence indicates that in early stages of type-2 diabetes and some types of monogenic diabetes linked with malfunctioning endoplasmic-reticulum (ER), the ß-cell ER fails to process sufficient proinsulin once it becomes overloaded. These changes manifest with ER distention (ER-crowding) and deficiency of secretory granules. We hypothesize that insulin therapy may improves ß-cell function by alleviating ER-crowding. To support this hypothesis, we investigated pre-diabetic ß-cell changes in hProC(A7)Y-CpepGFP transgenic mice that develop prolonged pre-diabetes due to proinsulin dysmaturation and ER-crowding. We attenuated the ß-cell ER proinsulin synthesis with a treat-to-target insulin therapy while avoiding hypoglycemia and weight gain. Alleviation of ER-crowding resulted in temporary improvement in proinsulin maturation, insulin secretion and glucose tolerance. Our observations suggest that alleviation of pre-diabetic ER-crowding using a treat-to-target insulin therapy may improve ß-cell function and may prevent further metabolic deterioration.

In vivo misfolding of proinsulin below the threshold of frank diabetes.

OBJECTIVE: Endoplasmic reticulum (ER) stress has been described in pancreatic ß-cells after onset of diabetes-a situation in which failing ß-cells have exhausted available compensatory mechanisms. Herein we have compared two mouse models expressing equally small amounts of transgenic proinsulin in pancreatic ß-cells. RESEARCH DESIGN AND METHODS: In hProCpepGFP mice, human proinsulin (tagged with green fluorescent protein [GFP] within the connecting [C]-peptide) is folded in the ER, exported, converted to human insulin, and secreted. In hProC(A7)Y-CpepGFP mice, misfolding of transgenic mutant proinsulin causes its retention in the ER. Analysis of neonatal pancreas in both transgenic animals shows each ß-cell stained positively for endogenous insulin and transgenic protein. RESULTS: At this transgene expression level, most male hProC(A7)Y-CpepGFP mice do not develop frank diabetes, yet the misfolded proinsulin perturbs insulin production from endogenous proinsulin and activates ER stress response. In nondiabetic adult hProC(A7)Y-CpepGFP males, all ß-cells continue to abundantly express transgene mRNA. Remarkably, however, a subset of ß-cells in each islet becomes largely devoid of endogenous insulin, with some of these cells accumulating large quantities of misfolded mutant proinsulin, whereas another subset of ß-cells has much less accumulated misfolded mutant proinsulin, with some of these cells containing abundant endogenous insulin. CONCLUSIONS: The results indicate a source of pancreatic compensation before the development of diabetes caused by proinsulin misfolding with ER stress, i.e., the existence of an important subset of ß-cells with relatively limited accumulation of misfolded proinsulin protein and maintenance of endogenous insulin production. Generation and maintenance of such a subset of ß-cells may have implications in the avoidance of type 2 diabetes.