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Biomedical subjects

Lars G Svensson

Publications and source records attributed to Lars G Svensson.

At least 19 recordsLinked to original sources
PubMed2006

Surgery for paroxysmal atrial fibrillation in the setting of mitral valve disease: a role for pulmonary vein isolation?

BACKGROUND: It is unknown whether pulmonary vein isolation or a complete Cox-Maze procedure is needed to ablate paroxysmal atrial fibrillation in patients with mitral valve disease. Our objective was to assess the impact of different surgical treatments for this arrhythmia in patients undergoing mitral valve surgery. METHODS: From July 1993 to January 2004, 152 patients underwent combined surgical treatment of paroxysmal atrial fibrillation and mitral valve disease. Ablation procedures included pulmonary vein isolation alone (n = 31, 20%), pulmonary vein isolation with left atrial connecting lesions (n = 80, 53%), and Cox-Maze (n = 41, 27%). The latter had longer durations of atrial fibrillation than the former (p < 0.0001). Rhythm documented on 1,225 postoperative electrocardiograms was used to estimate prevalence of, and risk factors for, atrial fibrillation across time. Ablation failure was defined as occurrence of atrial fibrillation any time beyond 6 months after operation. RESULTS: Prevalence of postoperative atrial fibrillation peaked at 22% at 2 weeks and declined to 9% at 1 year. Risk factors included older age (p = 0.09), larger left atrium (p = 0.05), and rheumatic (p = 0.003) and degenerative etiologies (p = 0.03). Freedom from ablation failure was 84% at one year. Ablation procedure did not affect prevalence of atrial fibrillation or incidence of ablation failure. CONCLUSIONS: Pulmonary vein isolation alone may be adequate treatment for patients with paroxysmal atrial fibrillation undergoing mitral valve surgery, particularly when it is of short duration. A randomized trial is necessary to examine this strategy, especially in patients with longer duration of paroxysmal atrial fibrillation.

Aged↗
PubMed2006

Mitral valve surgery in the adult Marfan syndrome patient.

BACKGROUND: Because mitral valve dysfunction in adults with Marfan syndrome is poorly characterized, this study compares mitral valve pathophysiology and morphology with that of myxomatous mitral disease, documents types of mitral valve operations, and assesses long-term survival and durability of mitral valve surgery in Marfan patients. METHODS: From May 1975 to June 2000, 27 adults with Marfan syndrome underwent mitral valve surgery. Their valve pathophysiology and morphology was compared with that of 119 patients with myxomatous mitral disease undergoing surgery from September 1995 to March 1999. Survival and repair durability were assessed at follow-up. RESULTS: Compared with myxomatous disease patients, Marfan patients had less posterior leaflet prolapse (44% versus 70%, p = 0.01), more bileaflet (44% versus 28%, p = 0.09) and anterior leaflet prolapse (11% versus 3%, p = 0.07), and presented earlier for surgery (age 41 +/- 12 years versus 57 +/- 13, p < 0.0001). Marfan patients had longer and thinner leaflets. Mitral valve repair was performed less frequently in Marfan (16 of 27, 59%) than myxomatous disease patients (112 of 119, 94%). There were no hospital deaths; at 10 years, survival was 80% and freedom from reoperation 96%, with only 1 reoperation among the 16 repairs. CONCLUSIONS: Mitral valve pathophysiology and morphology differ between Marfan and myxomatous mitral valve diseases. Valve repair in Marfan patients is durable and gives acceptable long-term results, even in adults who present with advanced mitral valve pathology. With increasing use of the modified David reimplantation operation and sparing of the aortic valve, mitral valve repair is a greater imperative, particularly since we have not had to reoperate on any Marfan patients with reimplantations.

Adult↗
PubMed2006

Surgery for permanent atrial fibrillation: impact of patient factors and lesion set.

BACKGROUND: Whether a complete Cox-maze procedure is needed to ablate permanent atrial fibrillation in patients undergoing concomitant cardiac surgery is unknown. Our objective was to assess the effectiveness of different lesion sets in such patients. METHODS: From November 1991 to January 2004, 575 patients underwent surgical treatment of permanent atrial fibrillation (duration > 6 months); mitral valve disease was the primary indication for surgery in 74%. Procedures included pulmonary vein isolation alone (n = 68, 12%), pulmonary vein isolation with left atrial connecting lesions (n = 265, 46%), and Cox-maze (n = 242, 42%). Rhythm documented on 5,120 postoperative electrocardiograms was used to estimate time-related prevalence of, and risk factors for, atrial fibrillation. RESULTS: Prevalence of postoperative atrial fibrillation peaked at 46% two weeks after operation, declining to 24% at one year. Patient-related risk factors for increased prevalence included older age (p < 0.0001), larger left atrium (p < 0.0001), and longer duration of preoperative atrial fibrillation (p = 0.0008). The Cox-maze procedure and lesion sets resembling it created with alternative energy sources had a similarly low prevalence of late postoperative atrial fibrillation; in contrast, pulmonary vein isolation and lesion sets that did not include a lesion to the mitral anulus were less effective. CONCLUSIONS: This study suggests that in cardiac surgical patients with permanent atrial fibrillation the left atrial lesion set should include wide pulmonary vein isolation, at least one connection between right and left pulmonary veins, and a connection to the mitral anulus. Availability of alternative energy sources to create lesions sets has virtually eliminated the need for the cut-and-sew Cox-maze procedure.

Adult↗
PubMed2006

Does use of a right internal thoracic artery increase deep wound infection and risk after previous use of a left internal thoracic artery?

OBJECTIVE: To determine whether adding right internal thoracic artery to previous left internal thoracic artery bypass at reoperation increases deep sternal wound infection and hospital mortality, particularly in diabetic patients. METHODS: Reoperations (n = 2875; 2381 men) in patients with previous left internal thoracic artery bypass were performed between January 1990 and January 2003; 1939 (67%) had no repeat internal thoracic artery grafting, 923 (32%) received an additional right internal thoracic artery graft, and 13 (0.5%) had bilateral internal thoracic artery grafting with reuse of the left internal thoracic artery. Of the patients, 352 (12%) were insulin-treated and 590 (21%) non-insulin-treated diabetics. Multivariable logistic regression analysis was used to identify preoperative variables associated with right versus non-right internal thoracic artery use in diabetics and nondiabetics and to formulate propensity models. Propensity scores were used for matching and adjusted multivariable analyses of deep wound infection and hospital mortality. RESULTS: Deep wound infection occurred in 3.0% (7/230) of diabetics receiving right internal thoracic artery grafts, 2.2% (5/230) of propensity-matched diabetics receiving non-right internal thoracic artery grafts (P = .6), in 1.1% (6/538) of nondiabetics receiving right internal thoracic artery grafts, and in 1.0% (5/538) of matched non-diabetic patients receiving non-right internal thoracic artery grafts (P = .8). Corresponding hospital mortality in these matched groups was 1.7% (4/230) versus 6.1% (14/230) for diabetics (P = .02) and 2.6% (14/538) versus 3.5% (19/538) for nondiabetics (P = .4). Risk factors for deep wound infection included higher weight (P = .0003), higher New York Heart Association functional class (P = .03), and less severe left anterior descending disease (P = .03). Risk factors for death were (P < .02) emergency operation, mitral valve replacement, and greater number of saphenous vein grafts. CONCLUSIONS: Use of the right internal thoracic artery for reoperations does not increase the risk of deep wound infections in diabetics or nondiabetics and does not increase mortality.

Aged↗
PubMed2006

Surgical treatment of pseudoaneurysm of the thoracic aorta.

OBJECTIVES: To examine the clinical profiles, operative outcomes, and late results of patients with pseudoaneurysm of the thoracic aorta. METHODS: From 1990 to 2002, 60 patients underwent repair of aortic pseudoaneurysm: ascending aorta in 70%, ascending aorta and arch in 15%, descending aorta in 10%, and arch alone in 5%. Mean age was 53 +/- 15 years, and 70% were men. Of these, 50 (83%) had undergone previous cardiac surgery, including 22 (37%) composite valve graft operations. The preferred cannulation site was femoral-femoral (n = 27, 45%), with deep hypothermic circulatory arrest in 62% and retrograde cerebral perfusion in 33%; more recently, however, axillary cannulation has been preferred. RESULTS: Principal etiologies were graft infection in ascending aorta pseudoaneurysm and trauma in descending aorta pseudoaneurysm. Fifteen patients (25%) presented with chest pain, 13 (22%) with heart failure, and 20% with moderate or severe aortic regurgitation. The pseudoaneurysm was resected and the aorta replaced (n = 45, 75%) or repaired (n = 15, 25%) using various methods. Hospital mortality was 6.7% (n = 4). Reexploration for bleeding was required in 8.3%, and 3.3% had postoperative stroke. At 30 days, 5 years, and 10 years, survival was 94%, 74%, and 60% and freedom from reoperation was 95%, 77%, and 67%, respectively. CONCLUSIONS: Most patients with aortic pseudoaneurysm require ascending aorta and/or arch replacement, which can be accomplished with low operative mortality and morbidity. Long-term survival and freedom from reoperation in these young patients parallel those expected for complex cardiac and aortic disease.

Adult↗
PubMed2006

Combined staged procedures for the treatment of thoracoabdominal aneurysms.

PURPOSE: To examine the efficacy of a staged approach for the treatment of thoracoabdominal aneurysms, with open visceral revascularization followed by aortic endografting, in selected patients not considered candidates for conventional surgical repair. METHODS: A retrospective review was conducted of 13 consecutive patients (8 women; mean age 64 years, range 33-77) who underwent visceral bypass followed by endovascular thoracoabdominal stent-graft implantation since 1999. Three patients presented with symptomatic aneurysms and 2 with rupture. Two patients had connective tissue disorders. All patients were deemed unfit for conventional thoracoabdominal repair due to comorbid conditions. The procedures were tailored to the pathology and specific patient anatomical situation: 5 aortic dissections with aneurysmal degeneration and 8 aneurysms (5 Crawford type II, 2 type III, and 1 type IV). RESULTS: The patients underwent retrograde visceral bypass (11 iliovisceral and 2 infrarenal aortic to visceral artery) followed by endovascular aortic relining with Zenith TX2 devices (n=7), homemade endografts (n=5), or a Talent thoracic endograft (n=1). Six patients required either a proximal or distal direct aortic repair (2 infrarenal reconstructions, 3 arch elephant trunk grafts, and 1 ascending aortic repair), while 3 patients also underwent left carotid-subclavian bypass grafting. Two patients developed paraplegia (1 following a ruptured aneurysm), and 2 patients had transient paraparetic events. Two patients had acute renal failure requiring short-term dialysis. Three patients died within 30 days; 2 late aneurysm-related deaths were noted. Three patients developed endoleaks during follow-up. Mean lengths of stay were 13 days (7-30) for the visceral bypass and 12 (3-25) for the endovascular stent-graft. In addition, remaining procedures in 8 patients required a mean of 7 days (0-14) in hospital. CONCLUSION: Staged endovascular and open procedures are feasible for thoracoabdominal aneurysms in patients at prohibitive risk for open thoracoabdominal reconstruction. However, this approach still carries a significant risk of perioperative mortality and morbidity. The potential for less invasive alternatives should be investigated.

Adult↗
PubMed2005

The Cox maze procedure in mitral valve disease: predictors of recurrent atrial fibrillation.

OBJECTIVES: The Cox maze procedure is the gold standard for ablation of atrial fibrillation in patients undergoing mitral valve surgery, and new approaches to atrial fibrillation ablation must be compared with it. Therefore, we sought to determine the time-related prevalence of atrial fibrillation and its risk factors after combined Cox maze and mitral valve surgery. METHODS: From November 1991 through January 2004, 263 patients (mean left atrial diameter, 5.8 +/- 1.2 cm) underwent combined mitral valve surgery (repair in 71%) and a cut-and-sew Cox maze procedure for atrial fibrillation (permanent, 74%; persistent, 7%; paroxysmal, 16%). Rhythm documented on 2367 postoperative electrocardiograms was used to estimate the prevalence of atrial fibrillation across time. RESULTS: Hospital mortality was 1.9%. Postoperative atrial fibrillation prevalence peaked at 36% at 2 weeks, decreasing to 21% at 5 years. Risk factors for higher postoperative atrial fibrillation prevalence varied with time and included longer duration of preoperative atrial fibrillation (P = .003), larger left atrial diameter (P = .01), older age (P = .0002), and higher left ventricular mass index (P = .02). CONCLUSIONS: In some patients undergoing mitral valve surgery and a Cox maze procedure, atrial fibrillation recurs over time, mandating close, long-term follow-up of heart rhythm. Earlier operation and left atrial size reduction should be considered to improve results in selected patients.

Atrial Fibrillation↗
PubMed2005

Surgical ablation of atrial fibrillation with bipolar radiofrequency as the primary modality.

OBJECTIVES: In studying cardiac surgical patients undergoing atrial fibrillation ablation with bipolar radiofrequency, we sought to (1) quantify the time-related prevalence of atrial fibrillation postoperatively and identify its risk factors and (2) determine time-related ablation failure and its risk factors. METHODS: From November 2001 to January 2004, 513 patients underwent atrial fibrillation ablation (bipolar radiofrequency alone or with cryothermy) and other cardiac operations. Rhythm documented on 3495 postoperative electrocardiograms was used to estimate the prevalence of and risk factors for atrial fibrillation across time. Ablation failure was defined as occurrence of atrial fibrillation any time beyond 6 months after operation. RESULTS: Prevalence of postoperative atrial fibrillation peaked at about 1 month, decreased to 13% at 6 months, and gradually increased thereafter. Risk factors associated with increased prevalence varied by time period and included older age ( P = .004) for early occurrence, lesion set in permanent atrial fibrillation ( P = .02) for late occurrence, and larger left atrial diameter ( P = .02) and permanent atrial fibrillation ( P < .0001) for occurrence across the entire time span. Freedom from ablation failure was 72% at 12 months. Risk factors for ablation failure included lesion set in permanent atrial fibrillation ( P = .001), longer duration of atrial fibrillation ( P = .01), and larger left atrial diameter ( P = .03). CONCLUSIONS: Bipolar radiofrequency enables extension of ablation to most cardiac surgical patients with atrial fibrillation. Recurrence is influenced by the type and duration of atrial fibrillation, choice of lesion set in permanent atrial fibrillation, and left atrial size. Early operation, careful choice of lesion set, and left atrial reduction might enhance results.

Aged↗
PubMed2005

Endovascular repair of thoracic aortic lesions with the Zenith TX1 and TX2 thoracic grafts: intermediate-term results.

PURPOSE: This prospective study was designed to assess the technical success and outcome after patients with thoracic aortic pathology at high risk for conventional therapy were treated with the Zenith TX1 and TX2 endovascular graft. METHODS: Between 2001 and 2004, patients at high risk for conventional surgical therapy presenting with chronic aortic dissections, thoracic aneurysms, or aortobronchial or aortoesophageal fistulas were treated with a single- or multiple-piece endovascular grafts. Surgical modification of proximal or distal fixation sites was performed when necessary to establish adequate regions for device landing zones. Follow-up studies included radiographic evaluation before discharge and at 1, 6, 12, and 24 months. Aortic morphologic characteristics were determined by using three-dimensional imaging studies and centerline of flow measurements. Statistical analyses were performed with Kaplan Meier analysis to assess survival, factors predictive of poor outcome, and morphologic changes, including sac shrinkage. RESULTS: A total of 100 patients (42% women) were treated, including 81 aneurysms, 15 aortic dissections (with aneurysms), 2 patients with fistulous connections (1 aortobronchial and 1 aortoesophageal), 1 subclavian artery aneurysm, and 1 aortic rupture. Mean follow-up and aneurysm size were 14 months and 62 mm, respectively. Most patients (55%) had undergone prior aortic aneurysm repair. Surgical modifications were required to create adequate implantation sites in 29% patients, including 14 elephant trunk/arch reconstructions, 18 carotid-subclavian bypasses, and 4 visceral vessel bypasses. Iliac conduits were required in 19 patients. Overall mortality was 17%, and aneurysm-related mortality was 14% at 1 year. Sac regression (>5 mm maximum diameter decrease) was observed in 52% and 56% at 12 and 24 months. Growth was noted in one patient (1.6%) at 12 months. Endoleaks were detected in eight patients (8.5%) at 30 days and three patients (6%) at 12 months. Secondary interventions were required in 15 patients. Migration (>10 mm) of the proximal or distal stent was noted in three patients (6%) (two proximal and one distal), none of which required treatment or resulted in an adverse event. CONCLUSIONS: Acceptable intermediate-term outcomes have been achieved in the treatment of high-risk patients in the setting of both favorable and challenging anatomic situations with these devices. The complexity of the patient population, in contrast to endovascular infrarenal repair, attests to the differences in the pathophysiology aortic disease in the anatomic beds.

Adult↗
PubMed2005

The elephant trunk procedure: uses in complex aortic diseases.

PURPOSE OF REVIEW: The elephant trunk procedure is used for extensive aneurysms involving both the ascending aorta/aortic arch and the descending thoracic or thoracoabdominal aorta. RECENT FINDINGS: This is a high-risk staged procedure; however, with current techniques in our most recent series the survival rate was 98% for the first operation and 92% for the second. SUMMARY: With the more liberal use of hybrid procedures and endovascular stenting for the second stage of the elephant trunk procedure, the operation can be used more often in patients with severe comorbid disease, particularly respiratory problems.

Aorta↗
PubMed2005

Multi-institutional pivotal trial of the Zenith TX2 thoracic aortic stent-graft for treatment of descending thoracic aortic aneurysms: clinical study design.

Despite significant improvements in surgical techniques and perioperative management, the repair of descending thoracic aortic aneurysms remains a challenge with the potential for substantial morbidity and mortality. Over the past several years, buoyed by the technical success of endovascular repair of infrarenal abdominal aortic aneurysms, several case series reports of endovascular stent-graft placement for descending thoracic aortic aneurysms have demonstrated the potential safety and efficacy of this treatment modality. Several single-institution studies have documented promising results with these devices, but without controlled clinical trials, the data are insufficient to determine if thoracic aortic endografts provide equivalent or improved outcomes compared with standard open repair. We describe a study design of an ongoing prospective, nonrandomized, multi-institutional, investigational device exemption phase II pivotal clinical trial investigating the safety and effectiveness of the Zenith TX2 thoracic aortic endovascular graft in the elective treatment of patients with descending thoracic aortic aneurysms.

Aortic Aneurysm, Thoracic↗
PubMed2005

The ultimate development of mitral valve endocarditis: atrioventricular separation, atrioventricular groove abscess and hemorrhagic pericarditis.

A 52-year-old non-insulin-dependent diabetic man presented with cerebral emboli and mitral valve endocarditis with posterior leaflet vegetations and perforation. Surgical intervention demonstrated hemorrhagic pericarditis and an atrioventricular groove abscess. Extensive debridement of the pericardium, valve and abscess cavities, reconstruction of the mitral annulus with a patch of fresh autologous pericardium, and mitral valve replacement with a pericardial bioprosthesis was performed. The chest was left open. Postoperatively, the patient required dialysis and prolonged mechanical ventilation, but recovered well without recurrent endocarditis and was discharged home after 40 days.

Abscess↗