Journal of Cardiothoracic Surgery - Latest articles

A novel survival model of cardioplegic arrest and cardiopulmonary bypass in rats: a methodology paper

2008-08-19

Background: Given the growing population of cardiac surgery patients with impaired preoperative cardiac function and rapidly expanding surgical techniques, continued efforts to improve myocardial protection strategies are warranted. Prior research is limited to either large animal models or ex vivo preparations. We developed a new in vivo survival model that combines administration of anterograde cardioplegia with endoaortic crossclamping during cardiopulmonary bypass (CPB) in the rat. Methods: Sprague-Dawley rats were cannulated for CPB (n=10). With ultrasound guidance, a 3.5 mm balloon angioplasty catheter was positioned via the right common carotid artery with its tip proximal to the aortic valve. To initiate cardioplegic arrest, the balloon was inflated and cardioplegia solution injected. After 30 min of cardioplegic arrest, the balloon was deflated, ventilation resumed, and rats were weaned from CPB and recovered. To rule out any evidence of cerebral ischemia due to right carotid artery ligation, animals were neurologically tested on postoperative day 14, and their brains histologically assessed. Results: Thirty minutes of cardioplegic arrest was successfully established in all animals. Functional assessment revealed no neurologic deficits, and histology demonstrated no gross neuronal damage. Conclusion: This novel small animal CPB model with cardioplegic arrest allows for both the study of myocardial ischemia-reperfusion injury as well as new cardioprotective strategies. Major advantages of this model include its overall feasibility and cost effectiveness. In future experiments long-term echocardiographic outcomes as well as enzymatic, genetic, and histologic characterization of myocardial injury can be assessed. In the field of myocardial protection, rodent models will be an important avenue of research.

Excision of sympathetic ganglia and the rami communicantes with histologic confirmation offers better early and late outcomes in Video assisted thoracoscopic sympathectomy.

Sridhar Rathinam, Prakash Nanjaiah, Sivakumar Sivalingam and Pala B Rajesh — 2008-08-13

Background: Video-Assisted Thoracoscopic Sympathectomy (VATS) is an established minimally invasive procedure for thoracic sympathetic blockade in patients with hyperhidrosis,facial flushing and intractable angina. Various techniques using clips, diathermy and excision are used to perform sympathectomy. We present our technique of excision of the sympathetic chain with histological proof and the analysis of the early and late outcomes. Methods: We evaluated 200 procedures in 100 consecutive patients, who underwent Video assisted thoracoscopic sympathectomy by a single surgeon in our centre between September 1996 to March 2007. All patients had maximum medical therapy prior to surgery and were divided into 3 groups based on indications, Group1(hyperhidrosis: 48 patients), Group 2 (facial flushing: 26 patients) and Group 3(intractable angina: 26 patients) .The demography and severity of symptoms for each group were analysed. The endpoints were success rate, 30 day mortality, complications and patient's satisfaction. Results: 99 patients had bilateral VATS sympathectomy and 1 had unilateral sympathectomy.The conversion rate to open was 1(1 %).All patients had successful removal of ganglia proven histologically with no periperative mortality in our series. The complications included pneumothorax (6 %), acute coronary syndrome (2 %),transient Horneras syndrome (1 %), transient paraesthesia (1%), wound infection (4%), compensatory hyperhidrosis (18 %), residual flushing (3 %) and wound pain(6%). There were five late deaths in the intractable angina group at a mean follow up of 36.7 months. Overall success rates of abolishing the symptoms were 96.3%, 87.5% and 95.2% for Group 1, 2 and 3 respectively. Conclusions: Excision of the sympathetic chain with histological confirmation during VATS sympathectomy is a safe and effective method in treating hyperhidrosis, facial flushing and intractable angina with good long term results and satisfaction.

Unexpected limited chronic dissection of the ascending aorta

2008-07-18

We report a rare case of a limited chronic dissection of the ascending aorta that was accidentally discovered at operation performed for severe aortic stenosis and moderate to severe dilatation of the ascending aorta. Preoperative investigations such as transoesophageal echocardiography and cardiac catheterization missed the diagnosis of dissection. Intraoperative findings included a 3.5 cm eccentric bulge of the ascending aorta and a 5 mm circular shaped intimal tear comunicating with a limited hematoma or small dissection of the media layer. (The rarety of the report is that the chronic dissection is limited to a small area (approximatively 3.5 × 2.5 cm) of the ascending aorta).

Does physiotherapy reduce the incidence of postoperative complications in patients following pulmonary resection via thoracotomy? a protocol for a randomised controlled trial

2008-07-18

Background: Postoperative pulmonary and shoulder complications are important causes of postoperative morbidity following thoracotomy. While physiotherapy aims to prevent or minimise these complications, currently there are no randomised controlled trials to support or refute effectiveness of physiotherapy in this setting.Methods/DesignThis single blind randomised controlled trial aims to recruit 184 patients following lung resection via open thoracotomy. All subjects will receive a preoperative physiotherapy information booklet and following surgery will be randomly allocated to a Treatment Group receiving postoperative physiotherapy or a Control Group receiving standard care nursing and medical interventions but no physiotherapy. The Treatment Group will receive a standardised daily physiotherapy programme to prevent respiratory and musculoskeletal complications. On discharge Treatment Group subjects will receive an exercise programme and exercise diary to complete. The primary outcome measure is the incidence of postoperative pulmonary complications, which will be determined on a daily basis whilst the patient is in hospital by a blinded assessor. Secondary outcome measures are the length of postoperative hospital stay, severity of pain, shoulder function as measured by the self-reported shoulder pain and disability index, and quality of life measured by the Medical Outcomes Study Short Form 36 v2 New Zealand standard version. Pain, shoulder function and quality of life will be measured at baseline, on discharge from hospital, one month and three months postoperatively. Additionally a subgroup of subjects will have measurement of shoulder range of movement and muscle strength by a blinded assessor.DiscussionResults from this study will contribute to the increasing volume of evidence regarding the effectiveness of physiotherapy following major surgery and will guide physiotherapists in their interventions for patients following thoracotomy.Trial registrationThe study protocol is registered with the Australian and New Zealand Clinical Trials registry (ANZCTRN12605000201673).

Survival benefit of coronary-artery bypass grafting accounted for deaths in those who remained untreated

2008-07-17

Background: Currently there are no direct estimates of mortality reduction afforded by coronary-artery bypass grafting (CABG) that take into account the deaths among patients for whom coronary revascularization was indicated but who did not undergo the treatment. The objective of this analysis was to compare survival after the treatment decision between patients who underwent CABG and those who remained untreated. Methods: We used a population-based registry to identify patients with established coronary artery disease who were to undergo first-time isolated CABG. We measured the effect of surgical revascularization on survival after the treatment decision in two cohorts of patients categorized by symptoms, coronary anatomy, and left ventricular function. Results: One in 10 patients died during the five years after treatment decision. The hazard of death among patients who underwent CABG was 51 percent of that for the untreated group, the adjusted hazard ratio was 0.51 (95 percent confidence interval, 0.43 to 0.61). The effect was stronger when CABG was performed within the recommended time: adjusted hazard ratios were 0.43 (95 percent confidence interval, 0.35 to 0.53) and 0.58 (95 percent confidence interval, 0.48 to 0.70) for early and late intervention, respectively; chi-square for the difference between hazard ratios was 12.2 (P < 0.001). Conclusion: Estimates that account for patients who died before they could undergo a required CABG indicate a significant survival benefit of performing early surgical revascularization even for patients registered to undergo the operation on the non-urgent basis.

Pulmonary valve endocarditis caused by right ventricular outflow obstruction in association with sinus of valsalva aneurysm: a case report

Katsufumi Nishida, Osamu Fukuyama and Dean S Nakamura — 2008-07-16

Background: Right-sided infective endocarditis is uncommon. This is primarily seen in patients with intravenous drug use, pacemaker or central venous lines, or congenital heart disease. The vast majority of cases involve the tricuspid valve. Isolated pulmonary valve endocarditis is extremely rare. We report the first case of a pulmonary valve nonbacterial thrombotic endocarditis caused by right ventricular outlflow tract (RVOT) obstruction in association with a large sinus of Valsalva aneurysm.Case presentationA 60-year-old man with a six-week history of fever, initially treated as pneumonia and sinusitis with levofloxacin, was admitted to the hospital with a new onset of a heart murmur. An echocardiogram showed thickening of the pulmonary valve suggestive of valve vegetation. A dilated aortic root and sinus of Valsalva aneurysm measuring at least 6.4 cm were also identified. The patient was empirically treated for infective endocarditis with vancomycin and gentamycin for 28 days. Four months later, the patient underwent resection of a large aortic root aneurysm and exploration of the pulmonary valve. During the surgery, vegetation of the pulmonary valve was confirmed. Microscopic pathological examination revealed fibrinous debris with acute inflammation and organizing fibrosis with chronic inflammation, compatible with a vegetation. Special stains were negative for bacteria and fungi. Conclusion: This is the first case report of a pulmonary valve nonbacterial endocarditis caused by RVOT obstruction in association with a sinus of Valsalva aneurysm. We speculate that jets created by the RVOT obstruction and large sinus of Valsalva aneurysm hitting against endothelium of the pulmonary valve is the etiology of this rare nonbacterial thrombotic endocarditis.

Hydroxyethyl starch versus Ringer solution in cardiopulmonary bypass prime solutions (a randomized controlled trial)

2008-07-12

Background: In our study we compared the Ringer solution, which is the standard prime solution of our department, with the HES (Hydroxyethyl starch) 130-0.4 solution, which can be a potential alternative prime solution with an indispensable material for the cardio-pulmonary bypass applications. Methods: 140 patients undergoing to CABG (Coronary Artery Bypass Graft surgery) were electively enrolled to the study. 1500 ml Ringer solution + 200 ml mannitol + 60 ml sodium bicarbonate + 150 U/kg heparin was used as a prime solution to start cardiopulmonary by-pass in 70 patients which was defined as group 1. On the other hand, 1500 ml HES 130 - 0.4 + 200 ml mannitol + 60 ml sodium bicarbonate + 150 U/kg heparin was used as a prime solution in 70 patients in group 2. Results: INR (International Normalized Ratio), urea levels and blood platelet counts were significantly different between the groups. INR level was higher in group 1, while blood urea and creatinine levels and platelet count were higher in group 2 at the end of the 12th and 24nd hours postoperatively (p = 0.001).In this study, it was shown that the usage of HES 130-0.4 as a prime solution did not have negative effect on postoperative INR level, platelet count, the need for transfusion and the amount of drainage, despite the negative opinions that similar solutions caused coagulation disorders. Another interesting result of the study was that blood platelet count at 24th hour was statistically significantly higher in group 2 (p = 0.001). Conclusion: HES 130-0.4 solution is an alternative colloidal solution which can be used as the prime solution or as a mixture with the crystalloids in cardio-pulmonary bypass applications.

The effect of a large proximal haemodialysis arterio-venous fistula on weaning off cardiopulmonary bypass: case report

Brian Nyawo, Amit Pawale, Leena Pardeshi, David Talbot and Jonathan Forty — 2008-07-09

An increasing number of renal dialysis-dependent patients with Arterio-Venous fistulae are undergoing cardiac surgery.The fistula has important effects on systemic hemodynamics in dialysis patients. The flow is significantly and positively related to cardiac output and cardiac index, and inversely related to pulmonary vascular resistance.Few problems are encountered on cardiopulmonary bypass despite left to right shunting of blood. We present an unusual case in which a large brachial Arterio-Venous fistula with large collaterals prevented weaning off cardiopulmonary bypass.

Aberrant right subclavian artery and calcified aneurysm of kommerell's diverticulum: an alternative approach

2008-07-09

We report a 72 year-old man with dysphagia and dizziness. Aortography and Computed tomographic scans revealed the aberrant right subclavian artery arising from a calcified aneurysm of the Kommerell's diverticulum and bilateral carotid artery disease with atherosclerotic narrowing. Surgical relief was accomplished by excluding the aneurysm from circulation through the aortic arch and a 10 mm graft was interposed between the aberrant artery and the ascending aorta.

Transvenous right ventricular pacing in a patient with tricuspid mechanical prosthesis

Juan Sierra and José Rubio — 2008-07-09

We report a patient in whom permanent endocardial pacing was accomplished by passage of the electrode through a mechanical tricuspid valve. Echocardiography study showed a minimal tricuspid regurgitation.

Coronary artery fistula; coronary computed topography – The diagnostic modality of choice

SA Early, TB Meany, HM Fenlon and J Hurley — 2008-07-05

Coronary artery fistulae (CAF) are rare anomalies. They are vascular communications between the coronary arteries and other cardiac structures, either cardiac chambers or great vessels. There can be considerable variation in the course of a coronary artery fistula. We report a case of a coronary artery fistula between the left circumflex coronary artery and the right and left atria. CAF are often diagnosed by coronary angiogram, however with the advent of new technologies such as Coronary Computed Tomography Angiography (Coronary CTA) the course and communications of these fistulae can be delineated non-invasively and with greater accuracy.