Concomitant Surgical Ablation in Paroxysmal vs Persistent Atrial Fibrillation During Mitral Surgery.

BACKGROUND: Despite prospective randomized evidence supporting concomitant treatment of atrial fibrillation (AF) during mitral valve (MV) surgery, variation in surgical management of AF remains. We assessed longitudinal outcomes after surgical treatment of persistent or paroxysmal AF during MV surgery in Medicare beneficiaries. METHODS: All Medicare beneficiaries with a diagnosis of AF undergoing MV surgery (2018-2020) were evaluated. Patients were stratified by no AF treatment, left atrial appendage obliteration (LAAO) alone, or surgical ablation and LAAO (SA+LAAO). Doubly robust risk adjustment and subgroup analysis by persistent or paroxysmal AF were performed. RESULTS: A total of 7517 patients with preoperative AF underwent MV surgery (32.1% no AF treatment, 23.1% LAAO alone, 44.7% SA+LAAO). After doubly robust risk adjustment, AF treatment with SA+LAAO or LAAO alone were associated with lower 3-year readmission for stroke or bleeding. However, SA+LAAO was associated with reduced 3-year mortality and readmission for AF or heart failure compared with no AF treatment or LAAO alone. Compared with no AF treatment or LAAO alone, SA+LAAO was associated with lower composite end point of stroke (hazard ratio, 0.75) or death (hazard ratio, 0.83) at 3 years. Subgroup analysis identified similar longitudinal benefits of SA+LAAO in patients with persistent or paroxysmal AF. CONCLUSIONS: In Medicare beneficiaries with AF undergoing MV surgery, SA+LAAO was associated with improved longitudinal outcomes compared with LAAO alone or no AF treatment in patients with paroxysmal or persistent AF. These contemporary real-world data further clarify the benefit of SA+LAAO during MV surgery across all types of AF.

Robot-Assisted Diagnostic Laparoscopy: A Safe and Feasible Adjunct to the Management of Massive Spontaneous Pneumoperitoneum.

Pneumoperitoneum is the abnormal presence of free air in the peritoneal cavity. Oftentimes, it is a surgical emergency requiring exploratory laparotomy as most cases of pneumoperitoneum are due to perforated hollow viscus. However, not all pneumoperitoneum cases are surgical; nonsurgical pneumoperitoneum can arise from thoracic, abdominal, gynecologic, and other causes. We present a case of a 35-year-old male who developed a non-surgical pneumoperitoneum in the setting of drug overdose. The patient underwent robot-assisted diagnostic laparoscopy without findings of perforation or other pathology. Resolution of pneumoperitoneum was evidenced on follow-up computed tomography scan. This case emphasizes the importance of diagnostic laparoscopy in the setting of a confusing clinical picture and the feasibility of utilizing the robotic approach in hemodynamically stable patients.

Robotic mitral repair: maintaining quality at all levels of complexity.

Over the last two decades, robotic mitral valve surgery has evolved from application of standard repair techniques for focal degenerative disease to a broad range of repair techniques navigating nearly all mitral pathologies at different complexity levels, the latter only performed in highly experienced robotic programs. The basic setup and steps of the operation have been standardized and many groups have reported reproducibility, excellent long-term durability and exceedingly rare mortality rates comparable to sternotomy. This has created a surge of interest in robotic cardiac surgery by patients, referring physicians and cardiac surgeons, all seeking the least invasive approach to mitral valve repair. In response, a growing number of major institutions have initiated robotic programs. This article discusses the gaps in practice before the widespread shift to a robotic approach as a standard treatment of mitral valve disease. In addition, we describe our techniques to approach complex mitral pathologies that transcend current, limited patient selection criteria.

Apical Resection and Cryoinjury of Neonatal Mouse Heart.

Neonatal mouse hearts have a regenerative capacity similar to adult zebrafish. Different cardiac injury models have been established to investigate the regenerative capacity of neonatal mouse hearts, including ventricular amputation, cryoinjury, and ligation of a major coronary artery. While the ventricular resection model can be utilized to study how tissue forms and regenerates de novo, cryoinjury and coronary artery ligation are methods that might better mimic myocardial infarction by creating tissue damage and necrosis as opposed to the removal of healthy tissue in the ventricular amputation model. Here we describe methods of creating ventricular resection and cardiac cryoinjury in newborn mice.

Mononuclear diploid cardiomyocytes support neonatal mouse heart regeneration in response to paracrine IGF2 signaling.

Injury to the newborn mouse heart is efficiently regenerated, but this capacity is lost by one week after birth. We found that IGF2, an important mitogen in heart development, is required for neonatal heart regeneration. IGF2 originates from the endocardium/endothelium and is transduced in cardiomyocytes by the insulin receptor. Following injury on postnatal day 1, absence of IGF2 abolished injury-induced cell cycle entry during the early part of the first postnatal week. Consequently, regeneration failed despite the later presence of additional cell cycle-inducing activities 7 days following injury. Most cardiomyocytes transition from mononuclear diploid to polyploid during the first postnatal week. Regeneration was rescued in Igf2-deficient neonates in three different contexts that elevate the percentage of mononuclear diploid cardiomyocytes beyond postnatal day 7. Thus, IGF2 is a paracrine-acting mitogen for heart regeneration during the early postnatal period, and IGF2-deficiency unmasks the dependence of this process on proliferation-competent mononuclear diploid cardiomyocytes.

Differential regenerative capacity of neonatal mouse hearts after cryoinjury.

Neonatal mouse hearts fully regenerate after ventricular resection similar to adult zebrafish. We established cryoinjury models to determine if different types and varying degrees of severity in cardiac injuries trigger different responses in neonatal mouse hearts. In contrast to ventricular resection, neonatal mouse hearts fail to regenerate and show severe impairment of cardiac function post transmural cryoinjury. However, neonatal hearts fully recover after non-transmural cryoinjury. Interestingly, cardiomyocyte proliferation does not significantly increase in neonatal mouse hearts after cryoinjuries. Epicardial activation and new coronary vessel formation occur after cryoinjury. The profibrotic marker PAI-1 is highly expressed after transmural but not non-transmural cryoinjuries, which may contribute to the differential scarring. Our results suggest that regenerative medicine strategies for heart injuries should vary depending on the nature of the injury.

Wearable multi-channel microelectrode membranes for elucidating electrophysiological phenotypes of injured myocardium.

Understanding the regenerative capacity of small vertebrate models has provided new insights into the plasticity of injured myocardium. Here, we demonstrate the application of flexible microelectrode arrays (MEAs) in elucidating electrophysiological phenotypes of zebrafish and neonatal mouse models of heart regeneration. The 4-electrode MEA membranes were designed to detect electrical signals in the aquatic environment. They were micro-fabricated to adhere to the non-planar body surface of zebrafish and neonatal mice. The acquired signals were processed to display an electrocardiogram (ECG) with high signal-to-noise-ratios, and were validated via the use of conventional micro-needle electrodes. The 4-channel MEA provided signal stability and spatial resolution, revealing the site-specific electrical injury currents such as ST-depression in response to ventricular cryo-injury. Thus, our polymer-based and wearable MEA membranes provided electrophysiological insights into long-term conduction phenotypes for small vertebral models of heart injury and regeneration with a translational implication for monitoring cardiac patients.

Percutaneous cholecystostomy versus laparoscopic cholecystectomy in patients with acute cholecystitis and failed conservative management: a matched-pair analysis.

INTRODUCTION: The role of percutaneous cholecystostomy (PC) or laparoscopic cholecystectomy (LC) in the management of patients with acute cholecystitis presenting beyond 72 hours from the onset of symptoms is unclear and undefined. The aim of this study was to examine and compare the outcomes of PC or LC in the management of these patients, who failed 24 hours of initial nonoperative management. PATIENTS AND METHODS: A retrospective chart review between January 1999 and October 2010 revealed 261 patients with acute calculus cholecystitis beyond 72 hours from onset of symptoms who failed initial nonoperative management. Twenty-three of 261 (8.8%) underwent PC and were compared with a similar 1:1 matched cohort of LC, matched using sex, age, race, BMI, diabetes, and sepsis to minimize the influence of treatment selection bias. RESULTS: There was no significant difference between PC versus LC regarding morbidity [4/23 (17%) vs. 2/23 (9%), P=0.665] and mortality [3/23 (13%) vs. 0/23 (0%), P=0.233]. The length of hospital stay was significantly longer in the PC group (15.9±12.6 vs. 7.6±4.9 d, P=0.005). CONCLUSION: In this matched cohort analysis, PC failed to show a significant reduction in morbidity compared with LC and was associated with a significantly longer hospital stay.

Biologic versus nonbiologic mesh in ventral hernia repair: a systematic review and meta-analysis.

BACKGROUND: The current standard of treatment for most ventral hernias is a mesh-based repair. Little is known about the safety and efficacy of biologic versus nonbiologic grafts. A meta-analysis was performed to examine two primary outcomes: recurrence and wound complication rates. METHODS: Electronic databases and reference lists of relevant articles were systematically searched for all clinical trials and cohort studies published between January 1990 and January 2012. A total of eight retrospective studies, with 1,229 patients, were included in the final analysis. RESULTS: Biologic grafts had significantly fewer infectious wound complications (p < 0.00001). However, the recurrence rates of biologic and nonbiologic mesh were not different. In subgroup analysis, there was no difference in recurrence rates and wound complications between human-derived and porcine-derived biologic grafts. CONCLUSIONS: Use of biologic mesh for ventral hernia repair results in less infectious wound complications but similar recurrence rates compared to nonbiologic mesh. This supports the application of biologic mesh for ventral hernia repair in high-risk patients or patients with a previous history of wound infection only when the significant additional cost of these materials can be justified and synthetic mesh is considered inappropriate.

Argon beam coagulation versus fibrin sealant for hemostasis following liver resection: a randomized study in a porcine model.

BACKGROUND/AIMS: Bleeding from the raw liver surface represents a significant surgical complication after elective liver resection or hepatic trauma. The application of argon beam coagulation (ABC) has been proposed to improve hemostasis, but is associated with significant necrosis of the liver parenchyma. Topical hemostatic agents, i.e. fibrin sealant (FS), have also been recommended, yet the optimal management is under debate. This study compares the efficacy and safety of both methods following liver resection in an animal model. METHODOLOGY: Twenty pigs underwent liver resection, and were then randomized into ABC or FS group for treatment of raw liver surfaces. Intraoperative and postoperative parameters were studied. Animals were sacrificed at day 12, and extent of necrosis was assessed using a scoring system and morphometry. RESULTS: Intraoperative parameters did not show any significant difference between two groups except for shorter time of application in the FS group. Postoperatively, animals in the FS group showed significantly higher hemoglobin levels (p=0.0001). Histologically, FS showed a smaller depth of necrosis than ABC (p=0.022). CONCLUSIONS: The use of FS is superior to ABC for management of the raw liver surface after liver resection, in terms of application time, postoperative bleeding and the extent of liver tissue necrosis.

Single-access laparoscopic cholecystectomy versus classic laparoscopic cholecystectomy: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Single-incision laparoscopic surgery has been proposed as a minimally invasive technique with the advantages of fewer scars and reduced pain. The aim of this study was to perform a systematic review and meta-analysis of prospective randomized clinical trials of single-access laparoscopic cholecystectomy (SALC) versus classic laparoscopic cholecystectomy (CLC). METHODS: All randomized controlled trials were identified through electronic searches (MEDLINE, PubMed, SAGES, and Cochrane Central Register of Controlled Trials) up to October 2011. Methodologically appropriate clinical trials identified in the search process were included in a meta-analysis to provide a pooled estimate of effect. RESULTS: Nine true randomized controlled trials were included in the analysis and reported a total of 695 patients, divided into the SALC group of 362 patients and the CLC group of 333 patients. Median operating time was longer with 57 minutes in SALC versus 45 minutes in CLC (P=0.00001). There was no significant difference in length of stay (SALC 1.36 d vs. CLC 1.15 d, P=0.18). Conversion to laparotomy in either group was similar; however, in 18 of 66 SALC patients an additional instrument was used, compared with 1 of 67 CLC patients (P=0.0003). Complications were not significant different [16% in SALC vs. 12% in the CLC group (P=0.74)]. Median postoperative pain with the visual analog scale score was 3.8 points in SALC versus 3.15 points in the CLC group (P=0.48). Cosmetic satisfaction was significantly more satisfying with 9 points favoring SALC versus 0 points favoring CLC (P=0.0005) in contrast to the quality-of-life questionnaire where there was no significant difference in patient overall satisfaction between SALC and CLC groups (P=0.0515). CONCLUSIONS: SALC required longer operative times than CLC without significant benefits in patient overall satisfaction, postoperative pain, and hospital stay. Only satisfaction with the cosmetic result showed a significantly higher preference towards SALC.

FGF10 Signaling Enhances Epicardial Cell Expansion during Neonatal Mouse Heart Repair.

Unlike zebrafish and newt hearts, mammalian hearts have limited capacity to regenerate. Upon injury or disease, the adult mammalian hearts form a fibrotic scar. Recently, it was shown that neonatal mouse hearts can regenerate similarly to adult zebrafish hearts. However, this capacity quickly decreases after postnatal day 7 (P7). Understanding the molecular mechanisms underlying neonatal heart regeneration might lead to therapeutic approaches for regenerating adult mammalian hearts. In this study, we utilized an inducible transgenic mouse model to determine the effects of FGF10 growth factor over expression on neonatal mouse heart regeneration/repair. Over expression of FGF10 in myocardium enhanced the expansion of Wt1 positive epicardial cells at 21 days after heart injury through increased proliferation. However, this expansion of epicardial cells did not lead to increased epithelial-to-mesenchymal transition or affect fibroblast formation or fibrosis, as seen by vimentin expression, after heart injury. Furthermore, neither continuous nor transient expression of FGF10 did not affect scar thickness or length after heart injury in neonatal hearts. Our results suggest that FGF10 can regulate epicardial cell expansion of neonatal mouse hearts after injury; however, FGF10 alone is not sufficient to cause beneficial effects on heart repair.

Minimally invasive surgical approach for the treatment of gastroparesis.

BACKGROUND: Gastroparesis is a chronic disorder resulting in decreased quality of life. The gastric electrical stimulator (GES) is an alternative to gastrectomy in patients with medically refractory gastroparesis. The aim of this study was to analyze the outcomes of patients treated with the gastric stimulator versus patients treated with laparoscopic subtotal or total gastrectomy. METHODS: A retrospective chart review was performed of all patients who had surgical treatment of gastroparesis from January 2003 to January 2012. Postoperative outcomes were analyzed and symptoms were assessed with the Gastroparesis Cardinal Symptom Index (GCSI). RESULTS: There were 103 patients: 72 patients (26 male/46 female) with a GES, implanted either with laparoscopy (n = 20) or mini-incision (n = 52), and 31 patients (9 male/22 female) who underwent laparoscopic subtotal (n = 27), total (n = 1), or completion gastrectomy (n = 3). Thirty-day morbidity rate (8.3% vs. 23%, p = 0.06) and in-hospital mortality rate (2.7% vs. 3%, p = 1.00) were similar for GES and gastrectomy. There were 19 failures (26%) in the group of GES patients; of these, 13 patients were switched to a subtotal gastrectomy for persistent symptoms (morbidity rate 7.7%, mortality 0). In total, 57% of patients were treated with GES while only 43% had final treatment with gastrectomy. Of the GES group, 63% rated their symptoms as improved versus 87% in the primary gastrectomy group (p = 0.02). The patients who were switched from GES to secondary laparoscopic gastrectomy had 100% symptom improvement. The median total GCSI score did not show a difference between the procedures (p = 0.12). CONCLUSION: The gastric electrical stimulator is an effective treatment for medically refractory gastroparesis. Laparoscopic subtotal gastrectomy should also be considered as one of the primary surgical treatments for gastroparesis given the significantly higher rate of symptomatic improvement with acceptable morbidity and comparable mortality. Furthermore, the gastric stimulator patients who have no improvement of symptoms can be successfully treated by laparoscopic subtotal gastrectomy.

Evaluation of the effects of ischemic preconditioning with a short reperfusion phase on patients undergoing a coronary artery bypass graft.

PURPOSE: This study was conducted to evaluate the effects of ischemic preconditioning (IP) with a short period of reperfusion (2 min) during brief ischemic preconditioning (6 min) on patients undergoing coronary artery bypass grafting (CABG). METHODS: In a randomized controlled trial, 40 patients undergoing on-pump CABG with cold blood cardioplegia were allocated into two groups, one IP and one control. IP was induced by 2 cycles of ascending aorta clamping (2 min for each) followed by two reperfusion phases (1 min for each). Left ventricular ejection fraction (LVEF) was measured before and after surgery. Creatine phosphokinase (CK) and CK-MB were measured 12 hrs before surgery, immediately after aortic clamping, and 24 hrs after CABG. Postoperative myocardial infarction (MI), ventricular arrhythmia, duration of inotropic support, and hemodynamic parameters were also noted. RESULTS: More patients in the control group needed inotropic support (65% vs. 40%, P<0.05). Moreover, duration of inotropic support was longer in the control group (9 ± 1.2 vs. 3.8 ± 1.4 hrs, P<0.05). There were no significant differences between two groups regarding development of ventricular arrhythmia, MI, values of CK, CK-MB, and postoperative LVEF. No patient needed an intra-aortic balloon pump, and no deaths occurred. CONCLUSION: A short period of reperfusion phase declined post-CABG inotrope requirements; however, it did not reduce the cardiac enzymes. Our results suggested that reperfusion should be longer than 2 min to be capable of reducing cardiac enzymes.

Effect of milrinone on short-term outcome of patients with myocardial dysfunction undergoing coronary artery bypass graft: A randomized controlled trial.

BACKGROUND: Myocardial dysfunction needing inotropic support is a typical complication after on-pump cardiac surgery. In this study, we evaluate the effect of milrinone on patients with ventricular dysfunction undergoing coronary artery bypass graft (CABG). METHODS: Seventy patients with impaired left ventricular function [left ventricular ejection fraction (LVEF) < 35%] undergoing on-pump CABG were enrolled. Patients were randomized to receive either an intraoperative bolus of milrinone (50 microg/kg) or saline as placebo followed by a 24-hour infusion of each agent (0.5 microg/kg/min). Hemodynamic parameters and transthoracic echocardiographic measurement of systolic and diastolic functions were the variables evaluated. RESULTS: Serum levels of creatine phosphokinase (CPK), the MB isoenzyme of creatine kinase (CK-MB), occurrence of myocardial ischemia or infarction, and mean duration of using inotropic agents were significantly lower in the milrinone group (p < 0.05). There were no significant differences between the two groups regarding the development of ventricular arrhythmia, duration of cardiopulmonary bypass, intra-aortic balloon pump and inotropic support requirement, duration of mechanical ventilation, duration of intensive care unit stay and mortality rate. Although mean pre-operative LVEF was significantly lower in the milrinone group, there was no significant difference between post-operative LVEFs. CONCLUSIONS: We suggest that perioperative administration of milrinone in patients undergoing on-pump CABG, especially those with low LVEF, is beneficial.