Personalized surgical planning for coronary bypass graft configurations using patient-specific computational modeling to avoid flow competition in arterial grafts.

Objectives: Flow competition between coronary artery bypass grafts (CABG) and native coronary arteries is a significant problem affecting arterial graft patency. The objectives of this study were to compare the predictive hemodynamic flow resulting from various total arterial grafting configurations and to evaluate whether the use of computational fluid dynamics (CFD) models capable of predicting flow can assist surgeons to make better decisions for individual patients by avoiding poorly functioning grafts. Methods: Sixteen cardiac surgeons declared their preferred CABG configuration using bilateral internal mammary and radial arteries for each of 5 patients who had differing degrees of severe triple vessel coronary disease. Surgeons selected both a preferred 'aortic' strategy, with at least one graft arising from the ascending aorta, and a preferred "anaortic" strategy which could be performed as a "no-aortic touch" operation. CT coronary angiograms of the 5 patients were coupled to CFD models using a novel flow solver "COMCAB." Twelve different CABG configurations were compared for each patient of which 4 were "aortic" and 8 were "anaortic." Surgeons then selected their preferred grafting configurations after being shown predictive hemodynamic metrics including functional assessment of stenoses (instantaneous wave-free ratio; fractional flow reserve), transit time flowmetry graft parameters (mean graft flow; pulsatility index) and myocardial perfusion. Results: A total of 87.5% (7/8) of "anaortic" configurations compared to 25% (1/4) of "aortic" configurations led to unsatisfactory grafts in at least 1 of the 5 patients (P = 0.038). The use of the computational models led to a significant decrease in the selection of unsatisfactory grafting configurations when surgeons employed "anaortic" (21.25% (17/80) vs. 1.25% (1/80), P < 0.001) but not "aortic" techniques (5% (4/80) vs. 0% (0/80), P = 0.64). Similarly, there was an increase in the selection of ideal configurations for "anaortic" (6.25% (5/80) vs. 28.75% (23/80), P < 0.001) but not "aortic" techniques (65% (52/80) vs. 61.25% (49/80), P = 0.74). Furthermore, surgeons who planned to use more than one unique "anaortic" configuration across all 5 patients increased (12.5% (2/16) vs. 87.5% (14/16), P<0.001). Conclusions: "COMCAB" is a promising tool to improve personalized surgical planning particularly for CABG configurations involving composite or sequential grafts which are used more frequently in anaortic operations.

A predictive patient-specific computational model of coronary artery bypass grafts for potential use by cardiac surgeons to guide selection of graft configurations.

Cardiac surgeons face a significant degree of uncertainty when deciding upon coronary artery bypass graft configurations for patients with coronary artery disease. This leads to significant variation in preferred configuration between different surgeons for a particular patient. Additionally, for the majority of cases, there is no consensus regarding the optimal grafting strategy. This situation results in the tendency for individual surgeons to opt for a "one size fits all" approach and use the same grafting configuration for the majority of their patients neglecting the patient-specific nature of the diseased coronary circulation. Quantitative metrics to assess the adequacy of coronary bypass graft flows have recently been advocated for routine intraoperative use by cardiac surgeons. In this work, a novel patient-specific 1D-0D computational model called "COMCAB" is developed to provide the predictive haemodynamic parameters of functional graft performance that can aid surgeons to avoid configurations with grafts that have poor flow and thus poor patency. This model has significant potential for future expanded applications.

Long-term durability of a Perceval aortic valve implanted inside a calcified homograft root in a patient with Klippel-Trenaunay-Weber syndrome.

BACKGROUND AND AIMS: Perceval valves are sutureless surgical bioprostheses designed for the aortic position. We report on the use of a Perceval sutureless valve for redo aortic valve replacement inside a heavily calcified homograft root in a patient with Klippel-Trenaunay-Weber syndrome. MATERIALS AND METHODS: Anonymized patient case data was extracted from hospital electronic records. RESULTS: A now 62-year-old woman with Klippel-Trenaunay-Weber syndrome underwent homograft aortic root replacement for congenital aortic valve dysplasia when she was 39 years old. She re-presented in 2012 with severe symptomatic aortic regurgitation through the homograft root. Computed tomography scanning revealed a heavily calcified homograft root. In order to avoid a high-risk redo root replacement or a challenging sutured aortic valve replacement, she underwent Perceval sutureless aortic valve implantation. As of 9.5 years following Perceval implantation, the bioprosthetic valve function remains excellent, with no transvalvular regurgitation seen. DISCUSSION AND CONCLUSION: This case reveals the value of Perceval valve implantation in redo surgery inside a hostile calcified homograft aortic root. Furthermore, we highlight the long-term durability of the Perceval sutureless bioprosthesis.

Ruptured giant left anterior descending coronary artery pseudoaneurysm.

We report a rare case of a ruptured giant left anterior descending coronary artery pseudoaneurysm that necessitated salvage operative repair. This case affirms the life-threatening nature of this clinically significant pathology, as well as the need for emergent repair before pseudoaneurysm rupture to maximize the likelihood of patient survival.

A case of a retained chest drain.

Retention of an intercostal drain segment is an uncommon and infrequently reported complication of underwater seal drain use. We report the case of a 66-year-old New Zealand European male who underwent bilateral lung transplantation for severe chronic obstructive pulmonary disease and bronchiectasis. The patient required a return to the operating room for exploratory surgery after an intercostal drain severed during its attempted removal and became retained within the chest cavity. A deep suture had inadvertently been passed around the chest drain intraoperatively. In the event of such a complication, prompt recognition and removal of the retained segment is required. This novel case is reported to highlight the possibility of an entrapped suture as a cause of resistance when attempting to remove an intercostal drain. Kinking on a chest X-ray may also point to this problem, and senior input should be sought early if radiographic findings are coupled with clinical difficulties.

Physical and Psychological Consequences of Left Cardiac Sympathetic Denervation in Long-QT Syndrome and Catecholaminergic Polymorphic Ventricular Tachycardia.

BACKGROUND: Left cardiac sympathetic denervation reduces risk in long-QT syndrome (LQTS) and catecholaminergic polymorphic ventricular tachycardia. Side effects and patient satisfaction have not been systematically analyzed in patients who underwent left cardiac sympathetic denervation. Aims of this study included documenting physical and psychological consequences and patient satisfaction after left cardiac sympathetic denervation in LQTS or catecholaminergic polymorphic ventricular tachycardia. METHODS AND RESULTS: Patients with LQTS (N=40) and catecholaminergic polymorphic ventricular tachycardia (N=7) underwent video-assisted thoracoscopic left cardiac sympathetic denervation, with a median follow-up of 29 months (range, 1-67 months). Clinical records were reviewed; 44 patients completed a telephone survey. Of 47 patients (53%), 25 were preoperatively symptomatic (15 syncope, 7 near-drowning, and 3 resuscitated sudden death). Indications for left cardiac sympathetic denervation included ß-blocker intolerance (15; 32%) or nonadherence (10; 21%) and disease factors (18; 38%; catecholaminergic polymorphic ventricular tachycardia [6], near-drowning [2], exertional syncope [1], symptoms on therapy [2], LQT3 [1], QTc>520 ms [6]). Other indications were competitive sports participation (2), family history of sudden death (1), and other (1). Median QTc did not change among patients with LQTS (461±60 to 476±54 ms; P=0.49). Side effects were reported by 42 of 44 (95%). Twenty-nine patients (66%) reported dryness on left side, 26 (59%) a Harlequin-type (unilateral) facial flush, 24 (55%) contralateral hyperhidrosis, 17 (39%) differential hand temperatures, 5 (11%) permanent and 4 (9%) transient ptosis, 5 (11%) thermoregulation difficulties, 4 (9%) a sensation of left arm paresthesia, and 3 (7%) sympathetic flight/fright response loss. Majority of the patients were satisfied postoperatively: 38 (86%) were happy with the procedure, 33 (75%) felt safer, 40 (91%) recommended the procedure to others, and 40 (91%) felt happy with their scar appearance. CONCLUSIONS: Despite significant morbidity resulting from left cardiac sympathetic denervation, patients with LQTS and CPVT have high levels of postoperative satisfaction.

E-VITA Jotec open hybrid stent graft system for the treatment of complex thoracic aortic aneurysm and dissection--a four year experience.

INTRODUCTION: The management of complex aortic aneurysms and dissections involving both the aortic arch and descending aorta include operations associated with significant risks of mortality and morbidity. The advent of hybrid systems such as the E-VITA Jotec open hybrid stent graft system (E-VITA) provides the advantage of single stage repair with follow up repair of any remaining downstream aneurysm and dissection being easier to manage. METHODS: Herein we report a series of seven cases utilising E-VITA over a four year period. RESULTS: The average patient age was 66.9 years of age (range: 55-78 years). The average cardiopulmonary bypass and circulatory arrest times were 237.14 min and 47.83 min. There was one operative mortality. Follow up as far as three years revealed good results with few complications. CONCLUSION: The E-VITA is a feasible management option in the treatment of complex aortic aneurismal disease and dissections. It allows treatment of patients that may have previously not been considered suitable for two-stage surgical procedure.

Carbon dioxide insufflation in open-chamber cardiac surgery: a double-blind, randomized clinical trial of neurocognitive effects.

OBJECTIVE: The aims of this study were first to analyze neurocognitive outcomes of patients after open-chamber cardiac surgery to determine whether carbon dioxide pericardial insufflation reduces incidence of neurocognitive decline (primary end point) as measured 6 weeks postoperatively and second to assess the utility of carbon dioxide insufflation in cardiac chamber deairing as assessed by transesophageal echocardiography. METHODS: A multicenter, prospective, double-blind, randomized, controlled trial compared neurocognitive outcomes in patients undergoing open-chamber (left-sided) cardiac surgery who were assigned carbon dioxide insufflation or placebo (control group) in addition to standardized mechanical deairing maneuvers. RESULTS: One hundred twenty-five patients underwent surgery and were randomly allocated. Neurocognitive testing showed no clinically significant differences in z scores between preoperative and postoperative testing. Linear regression was used to identify factors associated with neurocognitive decline. Factors most strongly associated with neurocognitive decline were hypercholesterolemia, aortic atheroma grade, and coronary artery disease. There was significantly more intracardiac gas noted on intraoperative transesophageal echocardiography in all cardiac chambers (left atrium, left ventricle, and aorta) at all measured times (after crossclamp removal, during weaning from cardiopulmonary bypass, and at declaration of adequate deairing by the anesthetist) in the control group than in the carbon dioxide group (P < .04). Deairing time was also significantly longer in the control group (12 minutes [interquartile range, 9-18] versus 9 minutes [interquartile range, 7-14 minutes]; P = .002). CONCLUSIONS: Carbon dioxide pericardial insufflation in open-chamber cardiac surgery does not affect postoperative neurocognitive decline. The most important factor is atheromatous vascular disease.