Olivier Bouchot

An aortic ring: From physiologic reconstruction of the root to a standardized approach for aortic valve repair

OBJECTIVE We suggest standardizing aortic valve repair using a physiologic approach by associating root remodeling with resuspension of the cusp effective height and external subvalvular aortic ring annuloplasty. METHODS A total of 187 patients underwent remodeling associated with subvalvular aortic ring annuloplasty (14 centers, 24 surgeons). Three strategies for cusp repair were evaluated: group 1, gross visual estimation (74 patients); group 2, alignment of cusp free edges (62 patients); and group 3, 2-step approach, alignment of the cusp free edges and effective height resuspension (51 patients). The composite outcome was defined as recurrence of aortic insufficiency of grade 2 or greater and/or reoperation. RESULTS The operative mortality rate was 3.2% (n = 6). Treatment of a cusp lesion was most frequently performed in group 3 (70.6% vs 20.3% in group 1 and 30.6% in group 2, P < .001). Nine patients required reoperation during a follow-up period of 24 months (range, 12-45), 6 patients in group 1 and 3 patients in group 2. At 1 year, no patients in group 3 presented with composite outcome events compared with 28.1% in group 1 and 15% in group 2 (P < .001). Residual aortic insufficiency and tricuspid anatomy were independent risk factors for the composite outcome in groups 1 and 2. The annulus diameter, the presence of Marfan syndrome, and cusp repair had no effect on aortic insufficiency recurrence or reoperation. CONCLUSIONS A standardized and physiologic approach to aortic valve repair, considering both the aorta (root remodeling) and the valve (resuspension of the cusp effective height and subvalvular ring annuloplasty) improved the preliminary results and might affect their long-term durability. The ongoing Conservative Aortic Valve Surgery for Aortic Insufficiency and Aneurysm of the Aortic Root (CAVIAAR) trial will compare this strategy to mechanical valve replacement.

Risk analysis and long-term survival in patients undergoing resection of T4 lung cancer.

OBJECTIVE The aim of this study is to identify the risk group of patients with T4 lung cancer who could more likely benefit from surgical resection. METHODS Between January 1, 1990, and December 31, 1998, 77 patients underwent pulmonary resection for T4 lung cancer: lobectomy (n = 20), bilobectomy (n = 4) and pneumonectomy (n = 53). The T4 sites of mediastinal involvement were: Intrapericardiac portions of the pulmonary artery (n = 30), left atrium (n = 19), aorta (n = 8), superior vena cava (n = 8), carina (n = 7), the esophagus (n = 8) and the vertebral body (n = 6). Ten patients had multiple neoplastic nodules in the same lobe of the lung. RESULTS Overall survival rates at 1, 2 and 3 years were 46, 31 and 21%, respectively. Factors adversely affecting survival with univariate analysis included the localization of tumours in the lower lobe (P = 0.04) and both the involvement of superior and inferior mediastinal lymph nodes (P = 0.03). Multivariate analysis included two factors adversely affecting survival: the location of the primary tumour and the nodal stations involved. Regression tree analysis classified the patients into low-risk group (primary tumour in upper lobe or in main stem bronchus and pN0 or pN1 or superior or inferior mediastinal nodes involved), intermediate-risk group (primary tumour in upper lobe or in main stem bronchus and both superior and inferior mediastinal nodes involved, primary tumour in inferior lobe and pN0 or pN1 or inferior mediastinal nodes involved) and high-risk group (primary tumour in inferior lobe and both superior and inferior nodes involved). The 3-year survival rates were 36% for the low-risk group, 4% for the intermediate-risk group and 0% for the high-risk group (P = 0.006). CONCLUSIONS In patients with T4 lung cancer, the surgery can justify itself for tumours in the upper lobe or in the main stem bronchus and with pN0 or pN1.

An aortic ring to standardise aortic valve repair: preliminary results of a prospective multicentric cohort of 144 patients

OBJECTIVES Multiplicity of aortic valve repair or sparing techniques results in a lack of standardisation, limiting widespread adoption of such procedures. To treat dilated diameters at the aortic annular base and sinotubular junction while maintaining root dynamics, we propose a standardised and physiological repair approach to the surgical management of aortic root aneurysms, consisting of root remodelling, cusp re-suspension and subvalvular aortic ring annuloplasty. METHODS From May 2003 to September 2009, 144 unselected patients with aortic root aneurysms underwent remodelling with external subvalvular ring annuloplasty in 13 centres (21 surgeons). Preoperative aortic insufficiency (AI) > or =grade 2 was present in 63.9% (92), Marfan syndrome in 12.5% (18) and bicuspid valve in 22.9% (33). Cusp repair was performed in 40.3% (58) patients. RESULTS Valve repair was successful in all but two cases. Repair of cusp prolapse was necessary in 58 patients, significantly more frequent in bicuspid (24/33, 72.7%) than in tricuspid (34/111, 30.6%) valves (p<0.05). Operative mortality was 2.8% (four). Subvalvular ring implantation produced a significant annular base reduction from 27.6+/-2.5 mm to 20.5+/-2.6 mm (p<0.01) without significant mean trans-valvular gradient (7.2+/-1.7 mmHg). During follow-up (median 2.2 years (0.75-4.4, maximum 6.25 years)), five patients died while eight required a re-operation. Six were operated on during our early experience. Strategy for cusp re-suspension evolved over three operative periods, with a significant increase in the rate of cusp repair. From May 2003 to December 2006: eye balling evaluation (15/67 (22.4%)); from January 2007 to August 2008: alignment of cusp free edges (17/38 (44.7%)); and from September 2008 to September 2009: a two-step standardised repair consisting of alignment of cusp free edges and effective height re-suspension (26/39 (66.7%) p<0.05). Freedom from AI> or =grade 2 was 91.3% (115) at the end of follow-up. CONCLUSIONS Implantation of an external aortic ring provides a reproducible technique for aortic valve repair with satisfactory preliminary results. The ongoing CAVIAAR trial (Conservative Aortic Valve surgery for aortic Insufficiency and Aneurysm of the Aortic Root) will compare this standardised repair technique using an expansible aortic ring to mechanical valve replacement.

Sutureless, rapid deployment valves and stented bioprosthesis in aortic valve replacement: recommendations of an International Expert Consensus Panel.

OBJECTIVES After a panel process, recommendations on the use of sutureless and rapid deployment valves in aortic valve replacement were given with special respect as an alternative to stented valves. METHODS Thirty-one international experts in both sutureless, rapid deployment valves and stented bioprostheses constituted the panel. After a thorough literature review, evidence-based recommendations were rated in a three-step modified Delphi approach by the experts. RESULTS Literature research could identify 67 clinical trials, 4 guidelines and 10 systematic reviews for detailed text analysis to obtain a total of 28 recommendations. After rating by the experts, 12 recommendations were identified and degree of consensus for each was determined. Proctoring and education are necessary for the introduction of sutureless valves on an institutional basis as well as for the individual training of surgeons. Sutureless and rapid deployment should be considered as the valve prosthesis of first choice for isolated procedures in patients with comorbidities, old age, delicate aortic wall conditions such as calcified root, porcelain aorta or prior implantation of aortic homograft and stentless valves as well as for concomitant procedures and small aortic roots to reduce cross-clamp time. Intraoperative transoesophageal echocardiography is highly recommended, and in case of right anterior thoracotomy, preoperative computer tomography is strongly recommended. Suitable annular sizes are 19-27 mm. There is a contraindication for bicuspid valves only for Type 0 and for annular abscess or destruction due to infective endocarditis. Careful but complete decalcification of the aortic root is recommended to avoid paravalvular leakage; extensive decalcification should be avoided not to create annular defects. Proximal anastomoses of concomitant coronary artery bypass grafting should be placed during a single aortic cross-clamp period or alternatively with careful side clamping. Available evidence suggests that the use of sutureless and rapid deployment valve is associated with (can translate into) reduced early complications such as prolonged ventilation, blood transfusion, atrial fibrillation, pleural effusions and renal replacement therapy, respectively, and may result in reduced intensive care unit and hospital stay in comparison with traditional valves. CONCLUSION The international experts recommend various benefits of sutureless and rapid deployment technology, which may represent a helpful tool in aortic valve replacement for patients requiring a biological valve. However, further evidence will be needed to reaffirm the benefit of sutureless and rapid deployment valves.

High incidence of venous thrombosis after surgery for abdominal aortic aneurysm

OBJECTIVE The incidence of venous thromboembolism (VT) after aortic abdominal aneurysm (AAA) surgery is imprecisely reported. On one hand, thromboprophylaxis has improved, on the other hand, AAA patients have become older and/or present worse comorbidities. Herein, we prospectively analyzed the incidence of VT in a continuous series of patients operated on for AAA repair and looked for predictive factors. MATERIALS AND METHODS Between January 1, 2005, and December, 31, 2006, 193 consecutive patients (177 men and 16 women), mean age 73 (range, 47-93) underwent elective AAA repair, 137 open (71%) and 56 endovascular (29%), in our institution. Thromboprophylaxis consisted of thigh-length compression bandages or stockings, early mobilization, and a daily subcutaneous injection of low-molecular-weight heparin (enoxaparin 40 mg per day). Patients with renal insufficiency or aged over 80 were given unfractionated heparin (5000 IU twice a day). Heparin was started between day 1 and day 5 (median = day 1) after surgery, according to the prescription of the surgeon. A bilateral lower limb duplex venous compression ultrasonography scan using 3 to 7.5 MHz transducers was systematically done before and after surgery in each patient. Two groups were considered: group 1 with postoperative VT (n = 17) and group 2 without (n = 176). The 17 patients with VT were compared with 51 patients randomly chosen among the 176 patients without VT. Different characteristics such as venous risk factors, preoperative antithrombotic treatment, anatomical features of the AAA, and perioperative data were studied. RESULTS Seventeen patients (8.1%) were diagnosed with postoperative VT (15 asymptomatic deep vein thrombosis [DVT] and 2 symptomatic pulmonary embolisms [PE]). VTE tended to be more frequent in open (10.2%) than endovascular (5.3%) repair (P = .28). Among perioperative data, delay to thromboprophylaxis was related to bleeding complication (P = .05) and blood transfusion (P = .02), and tended to be longer in VT patients (1.7 +/- 1.4 vs 0.9 +/- 0.9 day; P = .09). CONCLUSION Despite systematic prevention with heparin, surgery for AAA repair induces a high incidence of postoperative VT. This series mandates for vigilance about VT, with particular attention to the patients who received transfusion with fresh frozen plasma. Even though this series is one of the largest ever published on this topic, the rarity of the events calls for confirmation with a larger prospective study.

Influence of age and sex on aortic distensibility assessed by MRI in healthy subjects

Magnetic resonance imaging (MRI) is particularly well adapted to the evaluation of aortic distensibility. The calculation of this parameter, based on the change in vessel cross-sectional area per unit change in blood pressure, requires precise delineation of the aortic wall on a series of cine-MR images. Firstly, the study consisted in validating a new automatic method to assess aortic elasticity. Secondly, aortic distensibility was studied for the ascending and descending thoracic aortas in 26 healthy subjects. Two homogeneous groups were available to evaluate the influence of sex and age (with an age limit value of 35 years). The automatic postprocessing method proved to be robust and reliable enough to automatically determine aortic distensibility, even on artefacted images. In the 26 healthy volunteers, a marked decrease in distensibility appears with age, although this decrease is only significant for the ascending aorta (8.97+/-2.69 10(-3) mmHg(-1) vs. 5.97+/-2.02 10(-3) mmHg(-1)). Women have a higher aortic distensibility than men but only significantly at the level of the descending aorta (7.20+/-1.61 10(-3) mmHg(-1) vs. 5.05+/-2.40 10(-3) mmHg(-1)). Through our automatic contouring method, the aortic distensibility from routine cine-MRI has been studied on a healthy subject population providing reference values of aortic stiffness. The aortic distensibility calculation shows that age and sex are causes of aortic stiffness variations in healthy subjects.

3D segmentation of abdominal aorta from CT-scan and MR images

We designed a generic method for segmenting the aneurismal sac of an abdominal aortic aneurysm (AAA) both from multi-slice MR and CT-scan examinations. It is a semi-automatic method requiring little human intervention and based on graph cut theory to segment the lumen interface and the aortic wall of AAAs. Our segmentation method works independently on MRI and CT-scan volumes and has been tested on a 44 patient dataset and 10 synthetic images. Segmentation and maximum diameter estimation were compared to manual tracing from 4 experts. An inter-observer study was performed in order to measure the variability range of a human observer. Based on three metrics (the maximum aortic diameter, the volume overlap and the Hausdorff distance) the variability of the results obtained by our method is shown to be similar to that of a human operator, both for the lumen interface and the aortic wall. As will be shown, the average distance obtained with our method is less than one standard deviation away from each expert, both for healthy subjects and for patients with AAA. Our semi-automatic method provides reliable contours of the abdominal aorta from CT-scan or MRI, allowing rapid and reproducible evaluations of AAA.

Clinical Experience With a Novel Thermosensitive Temporary Coronary Artery Occluder (LeGoo)

BACKGROUND A bloodless field is important for visualizing relevant anatomical structures and facilitating construction of high-quality coronary anastomoses during off-pump coronary artery bypass graft surgery (OPCABG). Currently employed devices can damage target arteries as well as myocardium and are not uniformly effective, especially with diseased arteries. METHODS LeGoo (Pluromed, Woburn, MA) is a thermosensitive polymer that is a viscous liquid at room temperatures and changes into a firm occlusive plug instantaneously when exposed to body temperatures. The polymer is nontoxic and neither metabolized nor absorbed. It dissolves spontaneously or can be dissolved at will by cooling. LeGoo was instilled through the arteriotomy of 99 coronaries in 50 patients during construction of OPCABG anastomoses. RESULTS LeGoo formed an occlusive endoluminal plug instantaneously and blocked blood flow into the surgical field. In 89 vessels with available information, the quality of bloodless field was satisfactory, without need for substantial use of blood removal systems or application of another device in 81 vessels (91%). Resort to other means was prompted by serious arrhythmia (1 case) epicardial bleeding (1 vessel), bleeding from collateral branches (3 vessels), and shortcomings in design of the injecting catheter (3 vessels) that has been corrected. Intraoperative and perioperative profiles of these patients were similar to those reported from other OPCABG series. Abnormal bleeding, coagulopathy, metabolic derangements, and evidence of LeGoo embolization were not observed. CONCLUSIONS In this first large-scale human experience, LeGoo had been an atraumatic, safe, and effective temporary coronary artery occluder. It produced a bloodless field during OPCABG in 91% of target vessels. Improvements on these results with further experience is anticipated.

Role for Endovascular Therapy in Chronic Mesenteric Ischemia

Chronic mesenteric ischemia is a rare condition that is caused by stenosis or occlusion of the mesenteric arteries and usually manifests as abdominal pain. While surgical revascularization has been the standard treatment for symptomatic patients, recent advances in interventional devices and techniques have made endovascular treatment feasible and effective. Percutaneous transluminal angioplasty with stent placement is now recognized as a minimally invasive means of obtaining good long-term results with an acceptable recurrence rate; consequently, the technique is suggested for the primary treatment of chronic mesenteric ischemia. The present article discusses the indications and principles of endovascular treatment, and reviews the literature, with emphasis on short- and long-term outcomes, particularly morbidity and mortality rates.

Randomized clinical trial comparing a thermosensitive polymer (LeGoo) with conventional vessel loops for temporary coronary artery occlusion during off-pump coronary artery bypass surgery.

BACKGROUND During off-pump coronary artery bypass graft (OPCABG) surgery, a bloodless surgical field is mandatory for visualization and construction of optimal coronary anastomoses. Presently used temporary vascular occluders are known to cause endothelial dysfunction and vessel injury. The present prospective multicenter randomized clinical trial evaluates safety and efficacy of a novel thermosensitive polymer (LeGoo) as an atraumatic temporary vascular occluder. METHODS Between July 2008 and February 2010, 110 patients undergoing OPCABG were randomized between LeGoo (LG) and conventional vessel loops (VL) for coronary artery occlusion during construction of the distal anastomosis. A semiquantitative 4-point scale was used to evaluate the degree of bloodless surgical field and surgical comfort. Duration of coronary artery occlusion was also recorded. Safety during the operation and ensuing 30 days was evaluated by a composite endpoint of major adverse cardiac events that consisted of death from all causes, graft occlusion, myocardial infarction, and low cardiac output. RESULTS Fifty-six patients (117 distal anastomoses) were randomly assigned to LG and 54 patients (122 anastomoses) to VL. There were 2 anastomoses crossed over from LG to the control arm, and 3 from control to LG. Five anastomoses in LG patients were treated with an alternative device (shunts). Satisfactory hemostasis was achieved in 88.0% of LG anastomoses (103 of 117) compared with 60.7% of VL anastomoses (74 of 122; p < 0.001). Mean total anastomotic time was 12.8 minutes in the LG group and 15.1 minutes in the VL group (p < 0.001). This difference was more pronounced for arteries on the posterior and lateral than on the anterior walls of the heart. Composite adverse events were similar in the two groups: 3 of 48 LG patients and 3 of 46 VL patients. There was 1 death in the LG group. One patient in the LG group and 1 in the VL arm had a myocardial infarction. No operation was converted from OPCABG to CABG with cardiopulmonary bypass. CONCLUSIONS LeGoo is a safe and effective temporary coronary occluder during OPCABG. It provided a dry surgical field for visualization of the anastomotic field and surgical comfort more frequently than conventional vessel loops. In addition, anastomotic times were shorter with LG. Major cardiac adverse events were similar in the LG and VL arms.