Dinesh Kurian

Impact of the learning curve for endoscopic vein harvest on conduit quality and early graft patency.

BACKGROUND Recent studies have suggested that endoscopic vein harvest (EVH) compromises graft patency. To test whether the learning curve for EVH alters conduit integrity owing to increased trauma compared with an open harvest, we analyzed the quality and early patency of conduits procured by technicians with varying EVH experience. METHODS During coronary artery bypass grafting, veins were harvested open (n=10) or by EVH (n=85) performed by experienced (>900 cases, >30/month) versus novice<100 cases, <3/month) technicians. Harvested conduits were imaged intraoperatively using optical coherence tomography and on day 5 to assess graft patency using computed tomographic angiography. RESULTS Conduits from experienced (n=55) versus novice (n=30) harvesters had similar lengths (33 versus 34 cm) and harvest times (32.4 versus 31.8 minutes). Conduit injury was noted in both EVH groups with similar distribution among disruption of the adventitia (62%), intimal tears at branch points (23%), and intimal or medial dissections (15%), but the incidence of these injuries was less with experienced harvesters and rare in veins procured with an open technique. Overall, the rate of graft attrition was similar between the two EVH groups (6.45% versus 4.34% of grafts; p=0.552). However, vein grafts with at least 4 intimal or medial dissections showed significantly worse patency (67% versus 96% patency; p=0.05). CONCLUSIONS High-resolution imaging confirmed that technicians inexperienced with EVH are more likely to cause intimal and deep vessel injury to the saphenous vein graft, which increases graft failure risk. Endoscopic vein harvest remains the most common technique for conduit harvest, making efforts to better monitor the learning curve an important public health issue.

Endoscopic Venous Harvesting by Inexperienced Operators Compromises Venous Graft Remodeling

BACKGROUND Endoscopic vein harvesting (EVH) is the standard of care for coronary artery bypass grafting (CABG) in the United States, but recent comparisons with open harvesting suggest that conduit quality and outcomes may be compromised in EVH. To test the hypothesis that problems with EVH may relate to its learning curve and conduit quality, we analyzed the quality and early function of conduits procured by technicians with varying experience in EVH. METHODS Experienced (more than 900 cases, n=55 patients) and novice (less than 100 cases, n=30 patients) technicians performed EVH during CABG. Subsequently, optical coherence tomography (OCT) was used to examine the conduits for vascular injury, with segments identified as injured being further examined for gene expression with an array of genes related to tissue injury. Conduit diameter was measured intra- and postoperatively (day 5 and 6 months, respectively) with OCT and computed tomographic angiography. RESULTS Endoscopic vein harvesting by novice harvesters resulted in a greater number of discrete graft injuries and greater expression of tissue-injury genes than EVH done by experienced harvesters. Regression analysis revealed an association between shear stress and early dilation of engrafted vessels (positive remodeling) (R2=0.48, p<0.01). Injured veins showed blunted positive remodeling at 5 days after harvesting and a greater degree of late lumen loss at 6 months. CONCLUSIONS Under normal conditions, intraluminal shear stress leads to positive remodeling of vein grafts during the first postoperative week. Injury to conduits, a frequent sequela of the learning curve for EVH, was a predictor of early graft failure and of blunted positive remodeling and greater negative remodeling of endoscopically harvested vein grafts. Given the current annual volume of cases in which EVH is used, rigorous monitoring of the learning curve for this procedure represents an important and unrecognized issue in public health.

How do we develop and implement a preoperative anemia clinic designed to improve perioperative outcomes and reduce cost

Treatment of anemia is one of the four pillars of patient blood management programs. Preoperative anemia is common and associated with increased perioperative morbidity after surgery and increased rates of blood transfusion. Effective treatment of preoperative anemia, however, requires advanced screening, diagnosis, and initiation of therapy weeks before elective surgery. Here we describe the development and implementation of a preoperative anemia screening and treatment program at Duke University Hospital.

Evidence-based guidelines are equivalent to a liberal computed tomography scan protocol for initial patient evaluation but are associated with decreased computed tomography scan use, cost, and radiation exposure

BACKGROUND We hypothesized that trauma patient evaluations using evidence-based treatment guidelines (evidence-based group [EBG]), which include serial examinations and limited computed tomography (CT) scans in an established trauma center, would be associated with equivalent outcomes but with decreased CT scan usage, decreased cost, and less radiation exposure compared with a liberal CT scan approach (conventional group [CONV]). METHODS Fifteen evidence-based treatment guidelines were developed using published literature and in collaboration with other institutional departments. These were implemented on July 1, 2010. Prospectively collected data during a 4-month period were compared with a similar period in 2008 when CONV was used. RESULTS In 2010 (EBG), there were 611 patients compared with 612 in 2008 (CONV). Their average Injury Severity Score was 11.93 versus 8.77 (p < 0.0001), and the total CT scans were 757 and 1194, respectively (p < 0.001). The average APACHE II and hospital length of stay did not significantly vary. No missed or delayed injuries were identified. Estimated CT scan charges were

A randomized clinical trial investigating the relationship between aprotinin and hypercoagulability in off-pump coronary surgery.

1,842,534 versus

Direct to consumer advertising of robotic heart bypass surgery

2,935,024. The average number of scans per patient were 1.2 (EBG) versus 1.9 (CONV). Regarding radiation dosimetry, the estimated average computed tomography dose index (CTDI) per patient were 36.7 versus 53.31 mGy, and the estimated average dose-length product per patient were 889.91 versus 1364.11 mGy·cm. CONCLUSION EBG, including serial examinations, provided equivalent diagnostic data to CONV for initial workup but reduced CT scan usage, CT scan charges, and average radiation exposure per patient. This strategy may be beneficial in institutions where serial monitoring can be assiduously provided. LEVEL OF EVIDENCE Case management study, level IV.

Echocardiographic Guidance for Surgical Excision of the Intracardiac Component of a Pheochromocytoma

BACKGROUND: Off-pump coronary artery bypass (OPCAB) surgery is associated with a hypercoagulable state in which the platelet thrombin receptor, protease-activated receptor-1 (PAR-1), helps propagate a thrombin burst within saphenous vein grafts. Aprotinin, used in cardiothoracic surgery mainly for its antifibrinolytic properties, also spares platelet PAR-1 activation due to thrombin. We hypothesized that this PAR-1 antagonistic property provides an antithrombotic benefit during OPCAB surgery. METHODS: Patients were randomly assigned to receive saline (n = 38) or a modified full-dose regimen of aprotinin (n = 37) IV during OPCAB surgery. Blood sampled perioperatively from the coronary sinus, skin wounds, and systemic circulation was analyzed to test coagulation and platelet function. Major adverse cardiovascular events were monitored by obtaining troponin I at 24 h (myocardial infarction), predischarge computed tomography angiography (vein graft thrombosis), and by clinical examination for stroke. RESULTS: Coronary sinus blood obtained immediately after OPCAB surgery showed significantly less activation in the aprotinin group, as judged by reduced formation of platelet-leukocyte conjugates (P < 0.02) and platelet-derived microparticles (P < 0.05). The aprotinin group showed inhibition of platelet aggregation induced by thrombin (P = 0.007) but not adenosine diphosphate. Thrombin generation, defined by F1.2 levels, was significantly reduced by aprotinin in the coronary sinus but not in skin wound incisions. Major adverse cardiovascular events were significantly reduced in aprotinin-treated patients (5.4% vs 29.7%, P < 0.05). Aprotinin also demonstrated antifibrinolytic properties through diminished red blood cell transfusion (P < 0.04) and reduced blood loss postoperatively (603 ± 330 vs 810 ± 415 mL, P < 0.004). CONCLUSION: This study demonstrates that aprotinin protects patients undergoing OPCAB surgery from a hypercoagulable state by diminishing thrombin-induced platelet activation and thrombin generation within saphenous vein grafts, while maintaining systemic hemostatic and antifibrinolytic benefits. These results support further investigation of aprotinin and other PAR-1 antagonists in OPCAB surgery.

Airway Management in a Patient with Wolf-Hirschhorn Syndrome.

Robotic assisted coronary artery bypass (r-CABG) is a relatively novel and less invasive surgery. A yearlong direct-to-consumer advertising (DTCA) campaign was initiated to provide the community with information regarding r-CABG, increase awareness, and recruit patients. In order to optimize information content and ensure appropriate messaging for future campaigns, we (a) analyzed the campaign effectiveness, and compared (b) service quality perceptions and (c) clinical outcomes following surgery across DTCA-responder and control groups.

Risk of renal dysfunction after less invasive multivessel coronary artery bypass grafting.

Pheochromocytomas are rare neuroendocrine tumors, with published incidence of 2 to 8 cases per million patients per year. The extension of these tumors into the vena cava and right atrium is rarely seen. Transesophageal echocardiography may be invaluable to delineate tumor extent and characteristics, which in turn may provide a useful tool to guide intraoperative surgical approach to these uncommon masses. In the case presented in this article, we describe the role of transesophageal echocardiography in guiding a safe and complete, excision of an invasive pheochromocytoma without embolization of tumor components.

Direct to consumer advertising of robotic heart bypass surgery: Effectiveness, patient satisfaction and clinical outcomes

We present a case of a 3-month-old female with Wolf-Hirschhorn syndrome (WHS) undergoing general anesthesia for laparoscopic gastrostomy tube placement with a focus on airway management. WHS is a rare 4p microdeletion syndrome resulting in multiple congenital abnormalities, including craniofacial deformities. Microcephaly, micrognathia, and glossoptosis are common features in WHS patients and risk factors for a pediatric airway that is potentially difficult to intubate. We discuss anesthesia strategies for airway preparation and management in a WHS patient requiring general anesthesia with endotracheal intubation.