Robot-Assisted Excision of a Left Ventricular Myxoma and Hemangioma.

Left ventricular masses are rare entities that often require surgical excision when diagnosed due to the risk of embolization. We report 2 separate patients presenting with evidence of cerebral embolization both of whom were diagnosed with isolated left ventricular masses and underwent surgical excision through a robot-assisted approach. Microscopic pathology revealed a myxoma and hemangioma, respectively. Both cases demonstrate that left ventricular masses can be feasibly excised through a robot-assisted minithoracotomy approach.

Elevated pre-operative serum peptides for collagen I and III synthesis result in post-surgical atrial fibrillation.

OBJECTIVES: This study sought to determine if serum markers for collagen I and III synthesis, the carboxyl terminal peptide from pro-collagen I (PICP) and the amino terminal peptide from pro-collagen III (PIIINP), correlate with left atrial (LA) fibrosis and post-operative atrial fibrillation (AF). BACKGROUND: AF after cardiac surgery is associated with adverse outcomes. We recently demonstrated that LA fibrosis is associated with post-operative AF in patients with no previous history of AF. METHODS: Fifty-four patients having cardiac surgery without a history of AF consented to left and right atrial biopsies and a pre-operative peripheral blood draw. Picrosirius red staining quantified the percentage of fibrosis, and reverse transcriptase polymerase chain reaction assessed atrial tissue messenger ribonucleic acid transcripts involved in the fibrosis pathway. PICP and PIIINP levels were measured using an enzyme immunosorbent assay. RESULTS: Eighteen patients developed AF, whereas 36 remained in normal sinus rhythm. LA fibrosis was higher in patients who developed AF versus normal sinus rhythm (6.13 ± 2.9% vs. 2.03 ± 1.9%, p = 0.03). LA messenger ribonucleic acid transcripts for collagen I, III, transforming growth factor, and angiotensin were 1.5- to 2.0-fold higher in AF patients. Serum PICP and PIIINP levels were highest in AF versus normal sinus rhythm (PICP: 451.7 ± 200 ng/ml vs. 293.3 ± 114 ng/ml, p = 0.006; PIIINP: 379 ± 286 pg/ml vs. 191.6 ± 162 pg/ml, p = 0.01). Furthermore, there was a linear correlation between LA fibrosis and serum PICP levels (R(2) = 0.2; p = 0.01), and of the markers, only PICP was independently associated with AF. CONCLUSIONS: This demonstrates that serum PICP and PIIINP levels correlate with the presence of LA fibrosis and may act as predictors for post-operative AF even in the absence of previous history of AF.

Robotic-assisted or minithoracotomy incision for left ventricular lead placement: a single-surgeon, single-center experience.

OBJECTIVE: Left ventricular (LV) resynchronization with epicardial lead placement after failed coronary sinus cannulation can be achieved with minimally invasive robotic-assisted (RA) or minithoracotomy (MT) incisions. We evaluated early outcomes and costs after RA and MT epicardial LV lead implantation at our academic center. METHODS: From 2005 to 2010, 24 patients underwent minimally invasive RA or MT epicardial LV lead placement for resynchronization. Patient characteristics, electrophysiologic features, outcomes, and costs were analyzed. RESULTS: Ten patients underwent RA and 14 underwent MT minimally invasive LV lead placement, with no 30-day mortality in either group. Younger patients underwent RA epicardial lead placement (63.8 ± 15.4 vs 75.6 ± 10.0 years; P = 0.03). In addition, although both groups had comparable body surface areas, RA patients had significantly higher body mass index versus MT patients (44.4 ± 17.5 vs 26.9 ± 7.1 kg/m, respectively; P = 0.003). Premorbid risk and cardiovascular profiles were similar across groups. Importantly, pacing threshold, impedance, and postoperative QRS interval were equivalent between groups. Significantly, both operating room and mechanical ventilation durations were higher with RA epicardial placement (P < 0.001). Despite equivalent outcomes, incision-to-closure interval was 48 minutes shorter with MT (P = 0.002). Absolute differences in direct costs between groups were negligible. Despite these differences, resource utilization and lengths of stay were equivalent. CONCLUSIONS: Epicardial LV lead placement is efficacious with either approach. Early outcomes and mortality are equivalent. Greater tactile feedback during operation and equivalent short-term outcomes suggest that MT minimally invasive LV lead placement is the more favorable approach for epicardial resynchronization.

Lung hernia following robotic-assisted mitral valve repair.

Lung hernia is an uncommon diagnosis characterized by lung tissue protruding through a chest wall defect. It may occur spontaneously, as a congenital defect, as a result of trauma, or as a postsurgical complication. We describe the occurrence of lung hernia and subsequent successful herniorraphy in two patients following robotic-assisted mitral valve repair.

Transcatheter arterial revascularization outcomes at vascular and general surgery teaching hospitals and nonteaching hospitals are comparable.

BACKGROUND: Outcomes following transcatheter interventions at vascular and general surgery teaching hospitals (STH) are unknown. We examine whether surgery training programs influence clinically relevant outcomes after commonly performed endovascular procedures. METHODS: Using an all-payer inpatient care database from 2008, we selected adults who underwent either endovascular carotid stenting, endografting of descending thoracic aortic aneurysm, endovascular abdominal aortic aneurysm repair, or peripheral arterial revascularization. Patients were stratified by procedures completed at Surgery Teaching (Participate in Accreditation Council for Graduate Medical Education [ACGME]-accredited vascular and general surgery programs), STH, or nonteaching hospitals (NTH). Hierarchical regression models assessed adverse outcomes and in-hospital mortality among groups. RESULTS: Of the 175,698 records, 44% of the patients were treated at STH, while 56% underwent procedures at NTH. The adjusted odds ratio of any complication or mortality at STH and NTH were similar. Transfers, weekend admissions, and nonelective cases were higher at STH (P < .001, respectively). Paradoxically, STH treated fewer patients with more than three comorbidities compared with NTH (STH: 47% vs NTH: 53%; P < .001). Surgical teaching status did not lower the adjusted odds of mortality for any procedure. Moreover, the occurrence of any complication (adjusted odds ratios, 0.9; 95% confidence interval, .82-1.14; P = .69) and mortality (adjusted odds ratios, 0.9; 95% confidence interval, .74-1.22; P = .67) were equivalent between vascular and general STH. CONCLUSIONS: Following commonly performed transcatheter vascular procedures, and despite more transfers, weekend admissions, and nonelective procedures completed at STH, complications, and mortality were comparable across centers.

Is body mass index a risk factor for isolated off-pump coronary revascularization?

OBJECTIVE: The influence of body mass index (BMI) as a risk factor for isolated off-pump coronary artery bypass (OPCAB) surgery is unknown. We postulated that BMI ≥ 30 kg/m(2) would adversely affect outcomes following OPCAB at our institution. METHODS: From 2002 to 2009, we selected 742 patients (primary, N = 709 [95.6%], re-operative, N = 33 [4.45%]) who underwent isolated OPCAB for analysis. Patients were stratified into groups by BMI: non-obese (BMI < 30 kg/m(2) ) and obese (BMI ≥ 30 kg/m(2)). Preoperative risk, operative characteristics, and postoperative outcomes were analyzed. Risk-adjusted models evaluated the occurrence of any complication and mortality. RESULTS: Overall crude mortality was 1.5% (11/742). When compared to non-obese (26.12 ± 2.72 kg/m(2)) recipients, the obese (35.81 ± 5.69 kg/m(2)) comprised younger patients (62.46 ± 9.96 years, p < 0.001). Number of diseased vessels, Left ventricular ejection fraction, and baseline renal function was equivalent across groups. Diabetes (53.24%) and hypertension (90.59%) were more prevalent among obese patients (p < 0.001, respectively). Internal mammary artery utilization (p = 0.47), endoscopic vein harvest (p = 0.74), and intra-aortic balloon pump use (p = 0.58) were similar between groups. Interestingly, postoperative blood product requirement was lower in obese versus non-obese recipients (47.35% vs. 56.72%, p < 0.01). Furthermore, intensive care unit stay (p = 0.93), mortality (p = 0.56), and discharge to home (p = 0.09) remained equivalent between groups. Importantly, multivariable logistic regression did not identify BMI ≥ 30 kg/m(2) as an independent predictor of any complication (p = 0.21) or mortality (p = 0.74). CONCLUSIONS: Obesity does not influence operative characteristics or effect outcomes after OPCAB. BMI ≥ 30 kg/m(2) should not be considered a prohibitive risk factor in isolated off-pump coronary revascularization.

Robot-assisted mitral valve repair: a single institution review.

OBJECTIVE: Mitral valve repair (MVR) is the definitive therapy for mitral myxomatous degeneration. Median sternotomy has been the traditional approach to repair until the advent of the da Vinci Surgical System (Intuitive Surgical, Inc., Sunnyvale, CA). Minimally invasive surgical approaches for mitral repair have been slow to gain acceptance in cardiac surgery. We review the MVR results from our single-institution academic robotic program. METHODS: From August 2004 through April 2008, patients who underwent a robotic-assisted (RA) MVR were identified. RA technique included a 4-cm right minithoracotomy, femoral cardiopulmonary bypass with transthoracic aortic occlusion, and RA-MVR. Repair types were combinations of quadrangular/triangular leaflet resection, sliding plasty, chordal transfer/replacement, and edge-to-edge approximation, with band annuloplasty in all cases. Postrepair echocardiography and morbidity follow-ups were completed in all patients. Our primary outcome was adequacy of repair, and secondary outcome was major complications. RESULTS: There were 43 patients (29 male and 14 female) who underwent RA-MVR for severe (4+) mitral regurgitation during the 4-year review. Average operative time was 272.26 minutes. Only one patient had mild postoperative mitral regurgitation, whereas 20 had trace and 22 had no regurgitation after repair. Mean ventilator time was 32.1 hours, and length of stay was 5.7 days. One third of the patients (33%) received postoperative-packed red blood cell transfusions (average: 2.4 units per patient). Twenty-eight percent of patients developed atrial fibrillation after repair. Most of the patients (95.3%) were discharged home. There were no 30-day mortalities. CONCLUSIONS: Based on our small single-institution experience, RA-MVR provides an effective treatment for severe mitral valve regurgitation. Although procedure durability is slowly being established, preliminary results are promising. Careful programmatic advances with an integrated team approach can facilitate acceptable postoperative outcomes and excellent MVR.

Left versus right atrial difference in dominant frequency, K(+) channel transcripts, and fibrosis in patients developing atrial fibrillation after cardiac surgery.

BACKGROUND: The development of atrial fibrillation (AF) after cardiac surgery is associated with adverse outcomes; however, the mechanism(s) that trigger and maintain AF in these patients are unknown. OBJECTIVE: The purpose of this study was to test our hypothesis that postoperative AF is maintained by high-frequency sources in the left atrium (LA) resulting from ion channel and structural features that differ from the right atrium (RA). METHODS: Forty-four patients with no previous history of AF who underwent cardiac surgery consented to LA and RA biopsies. Histologic sections evaluated fatty infiltration, fibrosis, and iron deposition; quantitative reverse transcription-polymerase chain reaction (RT-PCR) assessed ion channel expression. In a subset of 27 patients, LA and RA unipolar recording leads were also placed. In patients who developed AF, the dominant frequency (DF) for each lead was calculated using fast Fourier transform. RESULTS: DFs during AF were LA 6.26 +/- 0.8 Hz, RA 4.56 +/- 0.7 Hz (P <.01). RT-PCR revealed LA-to-RA differences in mRNA abundance for Kir2.3 (1.8:1) and Kir3.4 (2.3:1). While LA fibrosis was greater in patients developing AF compared with those remaining in normal sinus rhythm (10.8% +/- 11% vs. 3.8% +/- 3.5%; P = .03), the amount of LA fibrosis inversely correlated with the LA DF. CONCLUSIONS: This is the first demonstration of LA-to-RA frequency differences during postoperative AF, which are associated with LA-to-RA differences in mRNA levels for potassium channel proteins and LA fibrosis. These results strongly suggest that sources of AF after cardiac surgery are located in the LA and are stabilized by LA fibrosis.

Robotic-assisted excision of a left ventricular thrombus.

OBJECTIVE: : Left ventricular thrombus is a rare entity usually associated with myocardial infarction. The daVinci Surgical System (Intuitive Surgical, Inc., Sunnyvale, Calif) offers excellent visualization of the mitral subvalvular apparatus and should provide an effective means to excise a left ventricular mass. METHODS: : A 34-year-old man presented to an outside institution with fever of unknown origin and ulcerative colitis. As part of this workup, he underwent a transthoracic echocardiogram and subsequently a transesophageal echocardiogram that showed a 2-cm left ventricular apical pedunculated mass. He was referred to our institution for excision of this ventricular mass. Because of the pedunculated nature of the mass, he was deemed a candidate for a robotic-assisted minimally invasive approach. RESULTS: : The patient underwent successful robotic-assisted excision of a left ventricular mass. Total robotic time was 15 minutes. Pathology revealed that the mass was a left ventricular thrombus. The patient experienced an uneventful recovery and was discharged home in 4 days. CONCLUSIONS: : Left ventricular mass excision can be safely performed with the daVinci Surgical System. The daVinci Surgical System offers excellent visualization of the entire left ventricular cavity.

Atrial myxomas: pathologic types, tumor location, and presenting symptoms.

BACKGROUND: Atrial myxoma is the most common cardiac neoplasm. Although not widely reported, two anatomic types have been observed: solid and papillary. We examined whether differences in gross or microscopic appearance and location correlated with symptomatology, specifically congestive heart failure (CHF), neurologic symptoms, and embolic events. METHODS: We performed a retrospective review of atrial myxomas removed from 1972 to 2002, recording the clinical presentation, diagnostic modality, tumor location, gross, and microscopic features for each patient. Twenty-six patients (16 females and 10 males) had atrial myxomas excised. Two patients (one female and one male) were excluded due to unavailable pathologic slides. RESULTS: In 24 patients there were 15 solid and 9 papillary tumors. CHF was more prevalent in solid myxomas, while neurologic symptoms and embolic events were more common in papillary tumors. Tumor location further correlated with presenting symptoms. Ninety-two percent of patients presenting with CHF had tumors attached to the atrial septum. Extraseptal myxomas more frequently presented with neurologic (80% vs. 29%) and embolic features (50% vs. 25%). All patients exhibiting clefted tumor surface had a history of embolization. A higher percentage of solid myxomas (93%) showed hemorrhage within the tumor than with papillary (56%). CONCLUSIONS: CHF was more common with solid myxomas, and neurologic and embolization events were more common in the papillary type. Septal tumor location showed strong association with CHF, while extraseptal location correlated with neurologic events. We speculate that the various gross and microscopic patterns reflect secondary changes within these neoplasms over the course of their natural history.

Chemically modified tetracycline improves contractility in porcine coronary ischemia/reperfusion injury.

BACKGROUND: Reperfusion of ischemic myocardium has been implicated in extension of infarct size and deleterious clinical outcomes. Anti-inflammatory agents reduce this reperfusion injury. Chemically modified tetracycline-3 (CMT-3) (Collagenex Pharmaceuticals, Newtown, PA, USA) lacks antimicrobial properties yet retains anti-inflammatory activity. We examined infarct size and myocardial function in a porcine coronary artery occlusion/reperfusion model in CMT-3-treated and control animals. METHODS: Yorkshire pigs (n = 8) underwent median sternotomy, pretreatment with heparin (300 U/kg and 67 U/kg/hr IV) and lidocaine (1 mg/kg IV) and were divided into two groups. Group one (n = 4) had the left anterior descending artery (LAD) occluded for 1 hour, after which it was reperfused for 2 hours. Group two (n = 4) had an identical protocol to group one except CMT-3 (2 mg/kg IV) was administered prior to occlusion of the LAD. RESULTS: Animals receiving CMT-3 had significantly decreased infarct size in relation to the ventricular area-at-risk (AAR) (28 +/- 9% vs. 64 +/- 8%; p < 0.05). Myocardial contractile function was superior in the CMT-3 treatment, indicated by a higher cardiac index (2.9 +/- 0.3 vs. 2.0 +/- 0.3 L/min/m(2); p < 0.05) and stroke volume index (22 +/- 2 vs. 17 +/- 1 L/m(2)/beat; p < 0.05). CONCLUSIONS: CMT-3 decreased infarct size in relation to the AAR resulting in relative preservation of contractility, suggesting CMT-3 may improve outcomes during myocardial ischemia reperfusion.

Whole blood cardioplegia (minicardioplegia) reduces myocardial edema after ischemic injury and cardiopulmonary bypass.

While blood:crystalloid cardioplegia is the clinical standard for patients undergoing cardiopulmonary bypass (CPB), it has been postulated that whole blood minicardioplegia may benefit the severely injured heart by reducing cardioplegic volume, thereby reducing myocardial edema. To test this hypothesis, we compared the cardioprotection of a popular 4:1 blood:crystalloid cardioplegia to whole blood minicardioplegia (WB) in a porcine model of acute myocardial ischemia. Yorkshire pigs (n = 20) were placed on atriofemoral bypass and subjected to 30 minutes of global normothermic ischemia. Animals were randomized to receive either 4:1 cold cardioplegia (n = 10) or WB cold cardioplegia (n = 10) delivered antegrade continuously for 90 minutes. Baseline (BL) echocardiographic determination of left ventricular mass (LVM) was compared within groups for cardiac edema (%) measured by histologic morphometrics. All (100%) animals receiving WB were successfully weaned off CPB, whereas only 40% of animals receiving 4:1 were successfully weaned off CPB. Cardiac edema percentage (p < .004) and LVM (p < .05) were significantly decreased in the WB group compared with 4:1. WB cardioplegia increases the number of hearts successfully weaned from CPB and decreases cardiac edema in our porcine model of acute myocardial ischemia. This finding implies whole blood cardioplegia may be more protective in a select group of patients undergoing extended CPB time by decreasing myocardial edema.

Dynamic alveolar mechanics in four models of lung injury.

OBJECTIVE: To determine whether pathological alterations in alveolar mechanics (i.e., the dynamic change in alveolar size and shape with ventilation) at a similar level of lung injury vary depending on the cause of injury. DESIGN AND SETTING: Prospective controlled animal study in a university laboratory. SUBJECTS: 30 male Sprague-Dawley rats (300-550 g). INTERVENTIONS: Rats were separated into one of four lung injury models or control (n=6): (a) 2% Tween-20 (Tween, n=6), (b) oleic acid (OA, n=6), (c) ventilator-induced lung injury (VILI, PIP 40/ZEEP, n=6), (d) endotoxin (LPS, n=6). Alveolar mechanics were assessed at baseline and after injury (PaO2/FIO2 <300 mmHg) by in vivo microscopy. MEASUREMENTS: Alveolar instability (proportional change in alveolar size during ventilation) was used as a measurement of alveolar mechanics. RESULTS: Alveoli were unstable in Tween, OA, and VILI as hypoxemia developed (baseline vs. injury: Tween, 7+/-2% vs. 67+/-5%; OA: 3+/-2% vs. 82+/-9%; VILI, 4+/-2% vs. 72+/-5%). Hypoxemia after LPS was not associated with significant alveolar instability (baseline vs. injury: LPS, 3+/-2 vs. 8+/-5%). CONCLUSIONS: These data demonstrate that multiple pathological changes occur in dynamic alveolar mechanics. The nature of these changes depends upon the mechanism of lung injury.