[Prevention of venous thromboembolism following cardiac, vascular or thoracic surgery]. / Prévention de la maladie thromboembolique veineuse périopératoire en chirurgie cardiaque, vasculaire et thoracique.

In the absence of thromboprophylaxis, coronary artery bypass graft surgery (CABG), intrathoracic surgery (thoracotomy or video-assisted thoracoscopy), abdominal aortic surgery and infrainguinal vascular surgery are high-risk surgeries for the development of venous thromboembolic events (VTE). The incidence of VTE following surgery of the intrathoracic aorta, carotid endarterectomy or mediastinoscopy is unknown. Data from the litterature are lacking to draw evidence-based recommandations for venous thromboprophylaxis after these three types of surgeries, and the following guidelines are but experts'opinions (Grade D recommendations). Thromboprophylaxis is recommended after CABG (Grade D), with either subcutaneous (SC) low molecular weight heparin (LMWH) or SC or intravenous (i.v.) unfractioned heparin (UH) (PTT target = 1.1-1.5 time control value) (both grade D). This may be combined with the use of intermittent pneumatic compression device (Grade B). After valve surgery. The anticoagulation recommended to prevent valve thrombosis is sufficient in order to prevent VTE. We recommend thromboprophylaxis with either LMWH or low dose UH to prevent VTE after aortic or lower limbs infrainguinal vascular surgery (both grade B and D). Vitamine K antagonists (VKA) are not recommended in this indication (Grade D). We recommend thromprophylaxis following intrathoracic surgery via thoracotomy or videoassisted thoracoscopy (grade C). Either subcutaneous LMWH or subcutaneous or i.v. low dose UH may be used (Grade C). Efficacy of intermittent pneumatic compression device has been demonstrated in a study (grade C). VKA are not recommended (grade D). No further recommendation regarding the duration of thromboprophylaxis after these three types of surgeries can be made.

Gastric emptying in humans: influence of different regimens of parenteral nutrition.

Intravenous administration of nutrients can suppress oral food intake. Inhibition of gastric emptying (GE) is a potential explanation for this process. Inhibition of GE during parenteral nutrition (PN) and attenuation of this by parenteral nutrition enriched with branched-chain amino acids (BCAAs) was examined in nine healthy males maintained on standard liquid diets for 6 d before each of three GE studies. GE was measured by scintigraphy after ingestion of a liquid test meal, at weekly intervals, after a 6-h infusion of Ringer lactate solution (RL), peripheral PN, or PN with half the amino acids replaced with BCAAs (BCPN). With PN, gastric emptying during the first 50 min was delayed by 38% compared with RL infusion; BCPN attenuated the effect, suggesting that postabsorptive control of food intake may act through changes in GE. These findings have clinical potential to reduce interference with appetite and to optimize food intake during PN administration.

Cardiac valve papillary fibroelastoma: surgical excision for revealed or potential embolization.

OBJECTIVE: We have reviewed the case histories of 4 patients who underwent operations between September 1994 and November 1997 at Broussais Hospital for cardiac valvular papillary fibroelastoma. METHODS: Diagnosis was strongly suggested by echocardiography. Tumor locations were mitral (1), tricuspid (1), and aortic (2). Indications for operation were previous stroke for the mitral tumor, prophylaxis for the tricuspid tumor, syncopal episodes for the first aortic tumor, and transient ischemic attack and mesenteric ischemia for the second aortic tumor. RESULTS: Surgical excision with a conservative, valve-sparing approach was performed in all cases. For the first aortic tumor, aortic valve reconstruction was achieved with part of a cryopreserved aortic homograft cusp. Intraoperative transesophageal echocardiography showed no evidence of valvular regurgitation after excision in all cases. All patients had uneventful postoperative recoveries. No evidence of regurgitation or recurrence was seen on echocardiography at follow-up. CONCLUSIONS: Despite their histologically benign aspect, cardiac papillary fibroelastomas should be excised because of potential embolic complications. A conservative, valve-sparing approach is recommended, however, because of the absence of recurrence after total excision.

Endoscopic coronary artery bypass grafting with the aid of robotic assisted instruments.

OBJECTIVE: The development of endoscopic coronary artery bypass grafting has been limited because of poor visualization and increased technical difficulties in carrying out operations through ports. We investigated whether the use of robotic assisted instruments could minimize these difficulties. METHODS: After a period of technical development and training on cadavers (n = 8) with the Intuitive Surgical system (Intuitive Surgical, Inc, Mountain View, Calif), the first clinical application in coronary artery surgery was performed in 4 male patients (mean age 59 +/- 6 years) with the indication of grafting the left internal thoracic artery to the left anterior descending coronary artery. Robotic assisted 3-dimensional endoscopes and instruments were introduced into the left side of the chest through 3 intercostal ports. The Heartport system (Heartport, Inc, Redwood City, Calif) was used for arresting the heart during the anastomosis. RESULTS: In 2 patients, the harvesting of the left internal thoracic artery was completed endoscopically with robotic assisted instruments and the anastomosis to the left anterior descending artery was performed through a minithoracotomy with conventional instruments. In 2 other patients, the entire operation was completed endoscopically with robotic assisted instruments. Early postoperative coronary angiography demonstrated the patency of the grafts in all cases. At 6-month follow-up, all patients were free of symptoms. CONCLUSIONS: Robotic assisted instruments make endoscopic coronary bypass possible and open a new era in minimally invasive surgery.

Less invasive techniques for mitral valve surgery.

OBJECTIVE: Minimally invasive surgical techniques aim at reducing the consequences of currently used large incisions, such as bleeding, pain, and risk of infection. Although this new approach developed rapidly in coronary surgery, it remains questionable in mitral valve surgery. This article reports the longest experience with minimally invasive mitral valve surgery, with particular attention to approach and techniques. METHODS: From February 1996, the date of the first case of minimally invasive mitral valve reconstruction, to April 1997, 22 patients with a mean age of 54 +/- 2.7 years were subjected to mitral valve surgery performed with less invasive techniques. Exposure of the mitral valve was achieved through a minithoracotomy (n = 12) or a ministernotomy (n = 10). Video assistance was used in all cases. Peripheral arterial cannulation (n = 21) and venous drainage (n = 22) were used in most cases. RESULTS: In this series, valve surgery consisted in 19 repairs, two replacements, and one closure of a periprosthetic leak. In two cases it was necessary to convert to a larger incision. The average duration of cardiopulmonary bypass was 157 +/- 8.2 minutes, ventilatory assistance 16 +/- 4.6 hours, and intensive care unit stay 2.1 +/- 0.4 days. Two patients required reoperation for bleeding and another for early recurrence of mitral valve regurgitation. There were no deaths and all patients were discharged with normal valve function. At most recent follow-up, all patients were in functional class I, with resumption of normal activity. CONCLUSION: Mitral valve surgery can be performed safely by means of less invasive techniques, but with increased technical difficulty. A low asymmetric median sternotomy seems preferable to an anterior thoracotomy.

Study of muscular and ventricular function in dynamic cardiomyoplasty: a ten-year follow-up.

BACKGROUND: The basic physiologic principle underlying cardiomyoplasty is long-term electrostimulation of a latissimus dorsi muscle (LDM) wrapped around the heart to obtain a phasic activity that could be integrated with ventricular kinetics. The aim of cardiomyoplasty is to prolong survival and to improve the quality of life of patients with severe chronic and irreversible myocardial failure by improving systolic contraction and correcting diastolic dysfunction. METHODS: To evaluate the long-term outcome of cardiomyoplasty, we investigated 82 patients electively undergoing this procedure in-our hospital. All patients had severe chronic heart failure that did not respond to optimal medical treatment. Patients had a mean age of 50 +/- 12 years (84% males). The cause of heart failure was ischemic (55%), idiopathic cardiomyopathy (34%), ventricular tumor (6%), and other (5%). The mean follow-up was 4.3 years. RESULTS: The mean New York Heart Association functional class improved after operation from 3.2 to 1.8. Average radioisotopic left ventricular ejection fraction increased from 17% +/- 6% to 28% +/- 3% (p < 0.05). Stroke volume index increased from 35 +/- 9 to 46 +/- 8 ml/beat/m2 (p < 0.05). The heart size remained stable at long term (evaluated by echo and computed tomography scanning). After cardiomyoplasty the number of successive hospitalizations resulting from congestive heart failure was reduced to 0.4 hospitalizations/patient/year (before operation 2.5, p < 0.05). Computed tomography scans showed at long-term a preserved LDM structure in 82% of patients who underwent operation. Survival probability at 7 years was 54% for the totality of patients, and 66% for patients who underwent operation in New York Heart Association functional class 3. Five patients underwent heart transplantation after cardiomyoplasty (mean delay 29 months), principally as a result of the natural evolution of their underlying heart disease, without major technical difficulties. CONCLUSIONS: Our 10-year clinical experience demonstrates that cardiomyoplasty increases ejection fraction, improves functional class, and ameliorates quality of life. Ventricular volumes and diameters remain stable long term. LDM structure is maintained long term if electrostimulation is performed avoiding excessive myostimulation. Patient selection is the most important determinant for early and late outcome. Late death in patients undergoing cardiomyoplasty is principally due to sudden death. Our future aim is to incorporate a cardioverter-defibrillator in the cardiomyostimulator, thus improving long-term results. Cardiomyoplasty may delay or prevent end-stage heart failure and the need for heart transplantation.

Partial mitral homograft for tricuspid valve repair.

We report a case of partial replacement of the tricuspid valve by a mitral homograft in a young drug addict with right heart endocarditis. Operation was indicated because of sudden severe tricuspid regurgitation and persistence of vegetations despite appropriate antibiotic therapy. Partial tricuspid valve replacement was performed with a segment of mitral homograft reinforced by a semirigid prosthetic ring. At 30-month postoperative follow-up the patient was in excellent clinical condition with a satisfactory echocardiographic result.

Management of pseudoaneurysm of the ascending aorta performed under circulatory arrest by port-access.

Pseudoaneurysms of the ascending aorta following previous thoracic surgery pose a difficult surgical management problem. In this report, we present a case of a patient with aortic insufficiency and a pseudoaneurysm of the ascending aorta at the site of a previous anastomosis. The particularity of this case is in the atypical use of Port-Access technology (Heartport, Redwood City, CA) to overcome surgical concerns [1].

Double mitral homograft for recurrent bacterial endocarditis of the mitral and tricuspid valves.

A young patient suffering from acute bacterial endocarditis underwent reconstructive surgery of the mitral and tricuspid valves. One year later a recurrent endocarditis occurred that could not be controlled with antibiotic therapy. Two separate mitral homografts were used to replace both the mitral and the tricuspid valves. The homografts' papillary muscles were sutured side to side to the recipient's and a circumferential suture of the leaflet tissue was accomplished. Homograft implantation was associated with Carpentier ring annuloplasty of the atrioventricular valves. In the right sided position, the mitral homograft was oriented in an anti-anatomical manner and an inverted semi-rigid prosthetic ring of the mitral type was inserted. Clinical and echocardiographic follow up at four months was excellent.

Autologous pericardial patch harvesting site for cardiac valve repair: anatomic and morphometric considerations.

BACKGROUND AND AIMS OF THE STUDY: Short-term glutaraldehyde-fixed autologous pericardium is widely used in cardiac valve repair or in autologous pericardial bioprosthesis construction. The thinner the tissue, the better the fixation. The aim of this study was to determine thickness and useful surface area of pericardium in relation to harvesting site using a digital thickness counter (0.01 mm precision). METHODS: Parietal pericardium fragments were obtained from the pericardial sac of six fresh cadavers (group I). In the other groups, pericardial strips (80 x 30 mm) were obtained from patients undergoing surgery: group II patients (n = 5 females) and group III (n = 10 males) were non-cardiomegalic (cardiothoracic ratio (CTR)<0.5), while group IV patients (n = 5) were all cardiomegalic (CTR >0.5). RESULTS: Results were reported on a coloric scale according to measurement position. In group I, mean surface area was 93+/-18 cm2, and thickness gradually increased from 0.1 to 0.6 mm, maximally on the diaphragm, along the left heart side. In other groups, a gradual increase in thickness was identified towards the diaphragmatic zone. Significant differences in tissue thickness appear as a result of cardiomegaly, but are not related to the sex of the patients. CONCLUSIONS: Pericardium taken from the right anterior aspect of the pericardial sac in patients without cardiomegaly is the most appropriate tissue for valve reconstructive surgery, due to its thin nature and hence better fixation properties.

Aortic valve surgery in osteogenesis imperfecta: report of two cases and review of the literature.

Aortic insufficiency is a well known but uncommon valvular dysfunction in patients with osteogenesis imperfecta. In such cases, aortic valve surgery has rarely been performed, and carries a high risk of perioperative complications. We report two patients with osteogenesis imperfecta, who underwent elective successful aortic valve replacement. The surgical problems encountered in this connective tissue disorder are also reviewed.

Ebstein's anomaly: repair based on functional analysis.

OBJECTIVE: 'Classical' repair of Ebstein's anomaly is usually performed with transverse plication of the atrialized chamber. However, the anterior leaflet has restricted motion which is an important factor of the tricuspid valve insufficiency. We studied the long term results of mobilization of the anterior leaflet associated with longitudinal plication of the right ventricule. METHODS: From 1980 to July 2002, 191 patients (mean age 24.4+/-15 years (1-65)) were operated on. Anterior leaflet function was assessed on pre-op echocardiography and on surgical examination. Conservative surgery was possible in 187 patients (98%) and included mobilization of the anterior leaflet, longitudinal plication of the right ventricle and prosthetic annuloplasty in adults. Bidirectional cavo-pulmonary shunt was associated in 60 patients. Four patients had valve replacement. RESULTS: Hospital mortality occurred in 18 patients: 9% (95%CL: 6-15%) due to right ventricle (RV) failure in nine patients. Mean follow-up was 6.4 years (0.07-22). Actuarial survival was 82% at 20 years. Tricuspid valve insufficiency was 1 or 2+ in 80% of the cases. Reoperation occurred in 8% (16 patients). A successful second repair was obtained in ten patients. Electron beam computerized tomography (20 patients) demonstrated improved left ventricle ejection fraction 56-66% (P<0.05). Supraventricular tachycardia and pre-excitation syndromes were reduced from 23 to 5%. CONCLUSION: Conservative surgery is indicated for all symptomatic patients. The incidence of valve repair is high when leaflet mobilization is performed. Valve replacement can be avoided in most cases. Functional and hemodynamic results are excellent.

Dynamic cardiomyoplasty: clinical follow-up at 12 years.

OBJECTIVE: The purpose of this study is to evaluate the long-term outcome of dynamic cardiomyoplasty. This surgical technique was conceived to assist the failing heart. The many proposed mechanisms of action of cardiomyoplasty are: (1) systolic assist; (2) limitation of ventricular dilation; (3) reduction of ventricular wall stress (sparing effect); (4) ventricular remodeling with an active girdling effect; (5) angiogenesis; and (6) a neurohumoral effect. METHODS: We investigated 95 patients in our hospital undergoing this procedure due to severe chronic heart failure, refractory to optimal medical treatment. Patients had a mean age of 51 +/- 12 years. The etiology of heart failure was ischemic 55%, idiopathic 34%, ventricular tumor 6%, and other 5%. The mean follow-up was 44 months. RESULTS: The mean New York Heart Association (NYHA) functional class improved postoperatively from 3.2 to 1.8. Average radioisotopic left ventricular (LV) ejection fraction increased from 17 +/- 5 to 27 +/- 4% (P < 0.05). Stroke volume index increased from 32 +/- 7 to 43 +/- 8 ml/beat per m2 (P < 0.05). The heart size remained stable over the long term. Following cardiomyoplasty, the number of hospitalizations due to congestive heart failure was reduced to 0.4 hospitalizations/patient per year (preoperative: 2.5, P < 0.05). Computed tomography scans showed at long term a preserved latissimus dorsi muscle structure in 84% of patients. Survival probability at 7 years is 54%. Six patients underwent heart transplant after cardiomyoplasty (mean delay: 25 months), due to the natural evolution of their underlying heart disease. There were no specific technical difficulties. CONCLUSIONS: Clinically, this procedure reverses heart failure, improves functional class and ameliorates quality of life. The latissimus dorsi muscle histological structure is maintained at long-term, when postoperative electrostimulation is performed, avoiding excessive stimulation. Cardiomyoplasty may delay or prevent the progression of heart failure and the indication of cardiac transplantation.

Homograft replacement of the mitral valve in young recipients: mid-term results.

OBJECTIVE: Mitral homograft (MH) can represent an interesting alternative for valve replacement in the young. However, concerns have been expressed about the durability of valve allografts in children. We report our experience with MH replacement in young patients. METHODS: From 1993 to 1997, 13 young patients aged 3-25 years (mean 15+/-6 years) underwent total mitral valve (MV) replacement with a cryopreserved homograft (CH). All but one had previously undergone one or more cardiac operations. The indications were rheumatic disease (6), acute and subacute endocarditis (2), congenital heart disease (4), and systemic lupus endocarditis (1). RESULTS: No in hospital deaths are reported. Discharge echocardiogram showed a well-functioning MH in all but one patient. One patient was lost to follow-up. Follow-up ranged from 0.7 to 6.6 years (4.1+/-2.2). On follow-up two patients were doing well. Two patients died without reoperation and both had MV stenosis. Seven patients (54%) required reoperation: mean delay 4.17 years (0.7-7). In all cases, thickening, shrinking and calcification of the allograft were present. None of these seven had contributive histopathologic changes. One patient presenting recurrent MV insufficiency will require a reoperation. CONCLUSION: MV homograft is a safe and reproducible technique, but does not provide durable results and should not be used in young patients.

[The pericardium: a heterogeneous tissue. Anatomic and morphometric considerations]. / Le péricarde: un tissu hétérogène. Considérations anatomiques et morphométriques.

BACKGROUND AND AIMS OF THE STUDY: Short-term glutaraldehyde fixed autologous pericardium is widely used in cardiac valve repair or in autologous pericardial bioprosthesis construction. The thinner the tissue, the better the fixation. The aim of this study was to determine thickness and useful surface area of pericardium in relation to harvesting site using a digital thickness counter (0.01 mm precision). Parietal pericardium fragments were obtained from the pericardial sac of six fresh cadavers (group I). In the other groups, pericardial strips (80 x 30 mm) were obtained from patients undergoing surgery: group II patients (n = 5 females) and group III (n = 10 males) were non-cardiomegalic (cardiothoracic ratio (CTR) < 0.5)), while group IV patients (n = 5) were all cardiomegalic (CTR > 0.5). Results were reported on a coloric scale according to measurement position. In group I, mean surface area was 93 +/- 18 cm2, and thickness gradually increased from 0.1 to 0.6 mm, maximally on the diaphragm, along the left heart side. In other groups, a gradual increase in thickness was identified towards the diaphragmatic zone. Significant differences in tissue thickness appear as a result of cardiomegaly, but are not related to the sex of the patients. Pericardium taken from the right anterior aspect of the pericardial sac in patients without cardiomegaly is the most appropriate tissue for valve reconstructive surgery, due to its thin nature and hence better fixation properties.

Mechanisms of starvation diabetes: a study with double tracer and indirect calorimetry.

To analyze the mechanisms of fasting-induced glucose intolerance, glucose metabolism was studied before and after the ingestion of 75 g glucose in 24 normal subjects fasted for either 14 h (n = 12) or 4 days (n = 12). The techniques included intravenous infusion of [6-3H]glucose and oral administration of [1-14C]glucose combined with indirect calorimetry. Compared with the controls, the starved subjects exhibited the following differences in glucose metabolism during the 5 h after glucose ingestion. 1) Mean incremental levels were fourfold higher for glucose and 40% higher for insulin. 2) Absorption of oral glucose was delayed and prolonged, but total amount reaching systemic circulation in 5 h was identical in the two groups (approximately 63 g). 3) Suppression of hepatic glucose output was reduced (-12 +/- 1 vs. -22 +/- 2 g). 4) Consequently, the increment in peripheral appearance of total glucose (exogenous plus endogenous) was augmented (+ 52 +/- 2 vs. +41 +/- 2 g). 5) Mean glucose clearance increased significantly less (+28 +/- 7 vs. +96 +/- 10 ml/min). 6) Oxidation of oral glucose was reduced (9 +/- 2 vs. 36 +/- 3 g), and nonoxidative disposal (presumably storage) was enhanced (56 +/- 2 vs. 36 +/- 3 g) in the presence of an elevated fat oxidation (35 +/- 2 vs. 22 +/- 4 g). Thus the alterations in glucose homeostasis responsible for the starvation-induced glucose intolerance are located both at the splanchnic (hepatic) and peripheral levels.

Mycotic aneurysm of the left subclavian artery presented with hemoptysis in an immunosuppressed man: case report and review of literature.

We report the case of a 32-year-old man with a mycotic aneurysm of the left subclavian artery. This patient had immunosuppression caused by chemotherapy administered for treatment of leukemia. This aneurysm was revealed by two episodes of hemoptysis caused by a lung parenchyma fistulization. The patient was treated successfully by simple ligation and exclusion via a thoracotomy with partial lung resection. Histologic examination confirmed the presence of aspergilloma filaments in the false aneurysm. We suspect that aspergilloma could have been the cause of the mycotic aneurysm in this particular case. The literature on subclavian artery mycotic aneurysms is reviewed.