Dynamic behavior of suture-anastomosed arteries and implications to vascular surgery operations.

BACKGROUND: Routine vascular surgery operations involve stitching of disconnected human arteries with themselves or with artificial grafts (arterial anastomosis). This study aims to extend current knowledge and provide better-substantiated understanding of the mechanics of end-to-end anastomosis through the development of an analytical model governing the dynamic behavior of the anastomotic region of two initially separated arteries. METHODS: The formulation accounts for the arterial axial-circumferential deformation coupling and suture-artery interaction. The proposed model captures the effects of the most important parameters, including the geometric and mechanical properties of artery and sutures, number of sutures, loading characteristics, longitudinal residual stresses, and suture pre-tensioning. RESULTS: Closed-form expressions are derived for the system response in terms of arterial radial displacement, anastomotic gap, suture tensile force, and embedding stress due to suture-artery contact interaction. Explicit objective functionalities are established to prevent failure at the anastomotic interface. CONCLUSIONS: The mathematical formulation reveals useful interrelations among the problem parameters, thus making the proposed model a valuable tool for the optimal selection of materials and improved functionality of the sutures. By virtue of their generality and directness of application, the findings of this study can ultimately form the basis for the development of vascular anastomosis guidelines pertaining to the prevention of post-surgery implications.

Primary cardiac valve tumors.

To assess the prevalence, characteristics, and outcome of surgical treatment of primary cardiac valve tumors in a single center, we reviewed our experience in 6 women and 1 man, aged 49 to 76 years (mean, 64.7 years) who presented between 1999 and 2006. In one patient, the diagnosis of cardiac valve tumor was made incidentally on transesophageal echocardiography during aortocoronary bypass surgery. The others had clinical symptoms: angina or myocardial infarction in 3, congestive heart failure in 2, dyspnea and cerebrovascular ischemia in 1 patient each. Four of the 7 tumors were benign, and 3 were malignant. All patients survived the operation and recovered uneventfully. Midterm follow-up was available in all patients. Two patients with malignant tumors were considered unsuitable for adjuvant therapy by the oncologist; both died during follow-up from local tumor recurrence. All 5 survivors were categorized at the last follow-up as functional class I, with normal exercise tolerance. Excellent early and midterm surgical results can be obtained in patients with benign cardiac valve tumors, but the prognosis for those with a malignant tumor is poor.

Video-assisted pericardial fenestration for effusions after cardiac surgery.

Delayed-onset pericardial effusion following cardiac surgery can give rise to significant morbidity due to its presentation as well as management by traditional surgical techniques. An institutional experience of a video-assisted thoracoscopic technique to create a pericardial window, with the advantages of a minimally invasive approach combined with excellent visualization in such patients, was reviewed. A retrospective analysis was conducted on all patients undergoing video-assisted thoracoscopic for delayed pericardial effusion after cardiac surgery from January 2001 to January 2006 at our center. Seven patients with echocardiographically diagnosed delayed tamponade underwent video-assisted thoracoscopy; 5 were receiving anticoagulants after valve replacement, and 2 had undergone heart transplantation. Pericardial windows were created under general anesthesia and single-lung ventilation using 2 to 3 trocars. Mean operative time was 45 min. There were no complications of the thoracoscopic technique. Video-assisted thoracoscopic creation of a pericardial window is safe and effective treatment for loculated pericardial effusions secondary to cardiac surgery.

Primary pulmonary amyloidosis due to low-grade B cell lymphoma.

Pulmonary involvement is not an infrequent complication of systemic amyloidosis, although affected patients rarely have significant pulmonary symptoms. In contrast, localized (primary) pulmonary amyloidosis is rare. We report a case of pulmonary low-grade B cell lymphoma with amyloid production, causing localized pulmonary amyloidosis.

Unusual presentation of Takayasu arteritis.

Takayasu arteritis (TA) is an inflammatory arteritis involving large vessels, predominantly the aorta and its main branches. Angina pectoris or myocardial infarction may occur in 3-5% of patients. Symptomatic coronary artery disease may be in rare case the first sign of TA. We describe a case of a young woman in whom acute myocardial infarction and cardiogenic shock and stroke were the initial presentations of TA.

Optimizing early extubation after coronary surgery.

Early extubation after isolated coronary artery bypass surgery was assessed retrospectively in 545 of 779 patients treated by the same surgical team over one year. All underwent extubation within 10 hr of arrival at the cardiothoracic intensive care unit: 343 in < 6 hr and 202 in 6-10 hr. Operative mortality was 2.2%. Group comparisons revealed that patients who had earlier extubation were younger (61 vs. 66 years; p < 0.001), more likely to be male (72.5% vs. 61.3%; p < 0.05), with a shorter aortic crossclamp time (49.2 +/- 15.0 vs. 53.3 +/- 14.0 min; p < 0.05), cardiopulmonary bypass time (65 +/- 18.4 vs. 72.2 +/- 19.2 min; p < 0.05), intensive care unit stay (18.8 +/- 5.6 vs. 22.4 +/- 3.2 hr; p < 0.05) and postoperative hospital stay (5.2 +/- 2.2 vs. 6.0 +/- 2.4 days; p = 0.01). Extubation < 6 hr after cardiopulmonary bypass may accelerate recovery. The finding of no significant differences in clinical parameters between the groups suggests that efforts to further reduce the time to extubation might be worthwhile.

Validation of the 2000 Bernstein-Parsonnet score versus the EuroSCORE as a prognostic tool in cardiac surgery.

BACKGROUND: Intradepartmental and interdepartmental benchmarking requires scoring systems with reliability (calibration) and stability over the complete spectrum of periprocedural risk. The aim of this single-center study was to assess the performance of the 2000 Bernstein-Parsonnet risk stratification model in cardiac surgery, by itself and against the EuroSCORE. METHODS: A prospective observational design was used. The study group consisted of 1,639 consecutive patients of mean age 64.6 +/- 12.04 years who underwent elective or emergency cardiac surgery from January 2003 to June 2004. The probabilities of hospital death were estimated with the 2000 Bernstein-Parsonnet and EuroSCORE algorithms. The correlation of predicted and observed mortality was compared between the two models, and score validity was assessed by calculating the area under the receiver operating characteristic (ROC) curve. RESULTS: The patients were stratified into five risk groups according to their scores in the two models. For the 2000 Bernstein-Parsonnet model, findings were as follows: score 0-10: predicted mortality 0%-2.2%, observed mortality 0.6%; score 10.5-20: predicted 2.3%-4.7%, observed 2.3%; score 20.5-30: predicted 4.8%-10%, observed 6.7%; score 30.5-40: predicted 10.1%-23%, observed 11.5%; and score greater than 40: predicted 23.1%-80%, observed 29.9%. For the EuroSCORE, findings were as follows: score 0%-2%: predicted mortality 1.1%, observed mortality 0.6%; score 3%-5%: predicted 2.1%, observed 3.0%; score 6%-8%: predicted 4.1%, observed 3.5%; score 9-11: predicted 7.6%, observed 6.6.%; and score greater than 12: predicted 13.8%, observed 14.0%. There was good agreement between the observed and expected number of deaths, with both models. The area under the ROC curve was higher for the Bernstein-Parsonnet model (0.83, odds ratio [OR] 2.01, 95% confidence interval [CI] 1.75-2.31, p < 0.0001) than for the EuroSCORE (0.73, OR 1.05, 95% CI 1.04-1.07, p < 0.001). CONCLUSIONS: The 2000 Bernstein-Parsonnet model is a simple, objective system for the estimation of hospital mortality in patients undergoing cardiac surgery, with slightly higher calibration and discrimination than the EuroSCORE additive model.

Surgical excision of papillary fibroelastoma for known or potential embolization.

BACKGROUND AND AIM OF THE STUDY: Papillary fibroelastoma (PFE) is a rare and histologically benign tumor, but it may have malignant propensity for life-threatening complications. Herein are described four cases of PFE which reflect the clinical diversity of this lesion. The diagnostic and surgical approach utilized is also briefly reviewed. METHODS: The files of four patients with cardiac valvular PFE treated at the authors' center between January 2002 and November 2003 were reviewed. The diagnosis was strongly suggested by echocardiography. Tumors were noted in aortic (n = 2), mitral (n = 1) and tricuspid (n = 1) sites. Indications for surgery were myocardial infarction (both aortic tumors), previous stroke (mitral tumor), and preventive (tricuspid tumor). RESULTS: Surgical excision with a conservative, valve-sparing approach was performed in all cases. For the first aortic tumor, the aortic valve was reconstructed with a patch of autologous pericardium. None of the patients had evidence of valvular regurgitation after excision on intraoperative transesophageal echocardiography, and all had an uneventful recovery. There were no cases of recurrence or regurgitation on follow up echocardiography. CONCLUSION: PFE is an uncommon but increasingly recognized cause of embolic phenomena. Prompt identification allows for surgical excision, which seems to be curative, safe and well-tolerated. A conservative valve-sparing approach is recommended because of the absence of recurrence after total excision.

Anomalous hepatic venous drainage.

We present a 3-year-old boy born with anomalous hepatic venous drainage into the left atrium and a small sinus venosus atrial septum defect, in whom pulmonary arteriovenous malformations developed with progressive cyanosis. Surgical redirection of the hepatic venous drainage to the right atrium and closure of the atrial septal defect led to regression of the pulmonary arteriovenous malformations. However, in contrast to other reports, progressive pulmonary hypertension developed postoperatively.

Video-assisted thoracoscopic pericardial window for diagnosis and management of pericardial effusions.

BACKGROUND: Video-assisted thoracoscopy with the creation of a pericardial window is a noninvasive method of pericardial drainage. It also allows an excellent view of both the pleural cavity and pericardium and the precise selection of biopsy sites. We review our 3-year experience with this technique. METHODS: Between January 2001 and February 2004, 18 patients (10 men, 8 women; mean age 57 years) with echocardiographically diagnosed pericardial effusion underwent video-assisted thoracoscopy at our center. Pericardial windows were created under general anesthesia and single-lung ventilation using 2 to 3 trocars. Mean operating time was 46 minutes. A right thoracic approach was used in 16 patients and a left thoracic approach in 2. RESULTS: Microbiology and virology cultures of the pericardial fluid were negative. Histologic findings were compatible with tuberculosis in 2 cases and granulocytic sarcoma, infiltrating breast carcinoma, and infiltrating nonsmall cell carcinoma in 1 case each. In the remaining patients, the histologic diagnosis was chronic or subacute nonspecific pericarditis. Talc pleurodesis was performed in 3 patients for concomitant malignant pleural effusion. In 4 patients, the pericardial effusion occurred secondary to cardiac surgery; 3 were receiving anticoagulants after valve replacement, and 1 had a heart transplant. There were no complications of the thoracoscopy technique. CONCLUSIONS: Video-assisted thoracoscopic fenestration is an effective technique for pericardial drainage and biopsy. Apart from its diagnostic value, it allows the physician to fashion a pleuropericardial window for effective drainage while avoiding the complications of classic surgical procedures. Concomitant pleural and pulmonary disorders may be managed simultaneously.

Advantages of the ultrasonic harmonic scalpel for radial artery harvesting.

The aim of the study was to examine the safety and effectiveness of the Harmonic Scalpel for reducing spasm caused by thermal injury during radial artery harvesting. The study sample included 100 candidates undergoing coronary artery bypass grafting. In half the patients, radial artery harvesting was performed using the ultrasonic Harmonic Scalpel equipped with coagulating curved shears and a 14 cm scissor-grip handle and in the other half, hemostatic clips, scissors, and minimal electrocautery were employed. Comparison of outcome between the groups showed that radial artery harvesting with the Harmonic Scalpel was associated with a shorter harvesting time, lower frequency of spasm, larger internal diameter of the radial artery graft, and a significantly reduced need for clips to control bleeding than the standard method. In addition, there were no cases of hematoma or superficial wound infection in the arm, and no postoperative reduction in soft touch sensation or objective pin-prick sensation. In conclusion, the Harmonic Scalpel provides excellent control of bleeding without the need for potentially damaging electrocautery, and with a markedly decreased use of hemostatic clips. Harvesting time is also shorter. The minimized thermal injury decreases the rate of radial artery spasm. Further studies using additional objective measures are currently underway to confirm these findings.

Is there a reversal of pulmonary arteriovenous malformation after redirection of anomalous hepatic venous flow to the lungs?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether pulmonary arteriovenous malformation resolves after redirection of the anomalous hepatic venous flow to the lungs. Altogether 714 papers were found using the reported search, of which only 13 papers presented the best evidence to answer the clinical question. The author, journal, date and country of publication, patient group studied, study type and relevant outcomes of these papers are tabulated. We conclude that the exclusion of hepatic venous blood from the lungs can predispose the patient to intrapulmonary shunt, which can be reversed surgically by diverting the hepatic venous drainage to the right atrium.