Reinhard Moidl

The vacuum-assisted closure system for the treatment of deep sternal wound infections after cardiac surgery.

BACKGROUND The VAC system (vacuum-assisted wound closure) is a noninvasive active therapy to promote healing in difficult wounds that fail to respond to established treatment modalities. The system is based on the application of negative pressure by controlled suction to the wound surface. The method was introduced into clinical practice in 1996. Since then, numerous studies proved the effectiveness of the VAC System on microcirculation and the promotion of granulation tissue proliferation. METHODS Eleven patients (5 men, 6 women) with a median age of 64.4 years (range 50 to 78 years) with sternal wound infection after cardiac surgery (coronary artery bypass grafting = 5, aortic valve replacement = 5, ascending aortic replacement = 1) were fitted with the VAC system by the time of initial surgical debridement. RESULTS Complete healing was achieved in all patients. The VAC system was removed after a mean of 9.3 days (range 4 to 15 days), when systemic signs of infection resolved and quantitative cultures were negative. In 6 patients (54.5%), the VAC system was used as a bridge to reconstructive surgery with a pectoralis muscle flap, and in the remaining 5 patients (45.5%), primary wound closure could be achieved. Intensive care unit stay ranged from 1 to 4 days (median 1 day). Duration of hospital stay varied from 13 to 45 days (median 30 days). In-hospital mortality was 0%, and 30-day survival was 100%. CONCLUSIONS The VAC system can be considered as an effective and safe adjunct to conventional and established treatment modalities for the therapy of sternal wound infections after cardiac surgery.

Growth of the pulmonary autograft after the Ross operation in childhood

OBJECTIVE Excellent hemodynamic performance has been demonstrated after aortic valve replacement using the autologous pulmonary valve as described by D. Ross. However, in the pediatric population there is concern in regard to growth of the autograft and late dilatation in the systemic circulation. METHODS Since 1991, 30 children (mean age, 11.3+/-3.1 years) had aortic valve replacement with the pulmonary autograft as a root replacement. All children had yearly clinical and echocardiographic follow-up. RESULTS There were no perioperative deaths; one child died late in a car accident. At the last follow-up (mean follow-up, 4.3+/-2.6 years), all patients were in NYHA class I. There was one early reoperation, in which the autograft had to be reconstructed due to a leaflet perforation. There were no major valve related events. All children showed normal somatic growth. The annulus diameter increased significantly from 18+/-2 at surgery to 20+/-3.5 mm at the latest follow-up (P<0.004). The sinus also increased significantly in diameter from 29+/-4 at surgery to 34+/-2 mm at the last follow-up (P<0.001). This increase in autograft size, both for the annulus and the sinus, paralleled the increase in body surface area with no evidence for unproportional dilatation. Hemodynamic measurements demonstrated physiological peak gradients of 6.8+/-2.9 mmHg and no or trivial aortic insufficiency in 95% of this rapidly growing patient population. CONCLUSION These data demonstrate growth of the pulmonary autograft parallel to somatic growth without undue dilatation in the systemic circulation. The hemodynamics are excellent with regard to physiological gradients and no increase in aortic insufficiency.

Dilatation of the autograft root after the Ross operation.

OBJECTIVE Structural differences of the pulmonary root may predispose it to progressive dilatation in the systemic circulation after the Ross operation. We identified the incidence and risk factors of pulmonary autograft root dilatation. METHODS One hundred and seven adult patients (mean age of 36+/-11 years) were followed after the Ross operation since 1991 including an echocardiogram within 3 months of surgery and yearly clinical assessment and echocardiography. The autograft was measured at the maximum diameter of the sinus (SV) and aortic insufficiency (AI) assessed. A SV of >37 mm was considered as root dilatation and the incidence over time was calculated using the Kaplan-Meier method. Clinically relevant dilatation was defined as a root diameter of >42 mm. In addition, we determined the percentage change of the sinus diameter between the early and latest echocardiogram. Furthermore we tested the influence of patient variables and risk factors on dilatation. RESULTS By 1 year, dilatation was found in 21 patients (20%). The SV was >42 mm in eight patients (7%). By 7 years, only 45% of patients were free of dilatation. Eleven patients (10%) had a SV of >42 mm. Increase in SV was time related and linear. However, 90% of patients showed <25% dilatation during follow-up. Time from operation, early SV diameter, male gender and surgical technique were identified as significant risk factors of dilatation. However, dilatation has not lead to reoperation due to aneurysm formation or development of significant AI. CONCLUSIONS We conclude that time dependent autograft root dilation occurs but does not cause an increase in AI and need for reoperation up to 7 years. These findings warrant the pursuit of the concept of the Ross operation in young patients who regain excellent functional status and life style without anticoagulation.

Aortic arch surgery using bilateral antegrade selective cerebral perfusion in combination with near-infrared spectroscopy

OBJECTIVE Near-infrared spectroscopy (NIRS) complements online monitoring of cerebral oxygenation during aortic arch surgery. Its addition targets at an increase of safety of a complex procedure employing bilateral antegrade cerebral perfusion (BACP) and circulatory arrest under tepid blood temperatures. We report the outcome of NIRS-guided aortic arch surgery using BACP with moderate hypothermic circulatory arrest (MHCA). METHODS Between December 2006 and December 2008, NIRS was used in 13 patients (mean age: 67.5 ± 11.3 years) undergoing aortic arch repair using BACP combined with MHCA. The diagnosis was atherosclerotic thoracic aneurysms in eight and acute aortic dissection in five patients. Seven patients had a hemi-arch replacement, six underwent frozen stent-graft arch replacement and four patients had concomitant procedures such as coronary artery bypass grafting (CABG) or aortic valve surgery. Our regimen of employing an algorithm for adaptation of perfusion modalities included the threshold of the drop in regional cerebral oxygen saturation <55% and/or a drop in the total oxygen index (TOI) of 15-20% assessed by the means of NIRS. RESULTS The mean MHCA was 35 ± 16min and lowest bladder temperature was 26 ± 1.2°C. The mean TOI pre-MHCA was 66 ± 6.5%. Twelve out of 13 patients underwent bilateral perfusion because of unilateral drops below the threshold level of TOI (mean: 44±7.9%). In three patients, an organic psychosyndrome was observed. No patient developed permanent neurological dysfunction. CONCLUSION NIRS-guided BACP during MHCA allows a safe approach to complex aortic arch surgery. The drop of brain oxygenation values in the contralateral hemisphere during unilateral ACP strongly suggests the routine use of BACP, when circulatory arrest under tepid temperatures is used.

Echocardiographic results after repair of incompetent bicuspid aortic valves

INTRODUCTION Valve-related complications and the necessity of anticoagulation after aortic valve replacement have led to new operative techniques for correction of aortic insufficiency (AI). Fourteen patients with bicuspid aortic valves and significant AI underwent valve repair. METHODS Transthoracic echocardiography was performed preoperatively and 1 week postoperatively and in 10 patients who have come to follow-up so far. Operative procedures were triangular resection of one leaflet in all patients. Five patients had pericardial patch plasty in addition. RESULTS Mean AI decreased significantly from grade 3.5 +/- 0.1 preoperatively to 0.5 +/- 0.1 postoperatively (p < 0.001). Postoperatively, 10 patients had no or trivial AI (0 to 0.5), and 2 patients had mild AI (1 to 1.5). Within the first week, 2 patients were reoperated on after echocardiography established significant AI. Ventricular dimensions decreased from preoperative to postoperative and were normal after 1 year. At follow-up, 7 patients show no change of AI; in 3 patients AI increased to moderate because of dilatation of the sinus of Valsalva or the sinotubular junction. CONCLUSIONS Reconstruction of bicuspid aortic valves is feasible with good early results. Echocardiography shows that asymmetric sinuses may lead to early perioperative failures and postoperative dilatation of the proximal aorta to increasing AI. Operative techniques may have to consider the pathology of the proximal aorta.

Aortic valve resuspension in ascending aortic aneurysm repair with aortic insufficiency

BACKGROUND The known complications of prosthetic valve replacement in patients with an ascending aortic aneurysm and secondary aortic regurgitation who frequently have a morphologically normal aortic valve have prompted interest in valve-sparing aneurysm repair procedures. The aim of this study was to define the echocardiographic criteria for identifying suitable candidates for ascending aortic aneurysm repair that spares the aortic valve. We also examined the perioperative and intermediate-term results of this innovative procedure. METHODS Fifteen patients underwent ascending aortic replacement with resuspension of the native valve within a vascular prosthesis and reimplantation of the coronary ostia. Echocardiography was performed preoperatively and intraoperatively, before discharge, and during follow-up. Thirteen patients had nondissecting aneurysms, and 2 patients had a Standford type A aortic dissection. The mean age of the patients was 48 +/- 18 years. Only patients with morphologically normal aortic leaflets and leaflets of similar size were selected. RESULTS There was one death perioperatively, and this was due to sepsis. The procedure failed in 1 patient, and a valved conduit was implanted during the same operation. In the 13 others the aortic annulus diameter was significantly reduced from 27.1 +/- 2.2 mm preoperatively to 22.2 +/- 1.9 mm postoperatively (p < 0.05). The severity of aortic insufficiency decreased from 2.9 +/- 0.7 to 0.6 +/- 0.4 (p < 0.05). The peak aortic gradient increased from 11.5 +/- 6.5 to 20.3 +/- 16 mm Hg. A slight increase in the aortic annulus diameter to 24.3 +/- 1.0 mm and normalization of the peak aortic gradient to 9.8 +/- 7.8 mm Hg were noted at follow-up. There was no significant increase in aortic insufficiency. CONCLUSIONS In selected patients undergoing ascending aortic aneurysm repair who have normal aortic leaflets but secondary aortic regurgitation, the native valve can be spared through this novel operation. The aortic annulus size is reduced significantly, thereby effectively eliminating hemodynamically significant aortic regurgitation. The intermediate-term results are promising, but the long-term durability of this type of repair needs to be determined.

Pulmonary autograft valve replacement in the dilated and asymmetric aortic root

Pulmonary autograft aortic valve replacement is the only technique for implantation of a biologic, vital and thus nondegenerating valve. The technique of root replacement overcomes problems of asymmetric aortic roots and reduces the risk of malalignment, but bears the risk of dilatation. We have performed pulmonary autograft aortic root replacement in 20 patients (mean age 22 years, range 5-38). Twelve presented with aortic incompetence, 3 with stenosis and 5 with combined defects. Initially roots were implanted just supraannularly with two running suture lines. As the neo-aortic roots gradually dilated, we started to implant autografts intraannulary, but still one valve dilated and aortic incompetence (AI) increased from grade I to II. Consequently the remaining aortic wall was wrapped around the new root and the composite subsequently was reinforced by a circular absorbable mesh. In addition, the aorta and pulmonary valve were exactly sized and the aortic root was reduced by commissuroplasty stitches up to 6 mm in diameter in seven cases. The ventricular size decreased in all patients 10 days after surgery, the left ventricular end-diastolic diameters (LVEDD) from 58 +/- 12 to 52 +/- 10 mm (P = 0.0002; paired t-test) and left ventricular end-systolic diameter (LVESD) from 41 +/- 12 to 36 +/- 10 mm (P = 0.008), but the contractility did not change significantly (fractional shortening from 31 +/- 9% to 30 +/- 9%). The diameter of the new aortic ring increased for the supraannular position but size matching and the intraannular valve position reduced the new ring size significantly (P = 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Primary or delayed closure for the treatment of poststernotomy wound infections

ObjectiveThe methods of primary versus delayed wound closure for the treatment of sternal wound infections after cardiac surgery were retrospectively compared. MethodsFrom January 2001 to March 2003, 132 patients (median age 66 years, male to female ratio 88:44) with sternal wound infection after cardiac surgery were treated at our department. After thorough debridement, 35 patients received preconditioning of the wound before implementation of definitive therapy; the remainder (97 patients) were treated with immediate closure. ResultsFrom the 35 patients with preconditioning, 19 patients proceeded to delayed primary closure, whereas the remaining 14 patients were referred to plastic reconstruction with a pectoralis muscle flap. Primary success rate in this group was 100%.In the immediate primary closure group, 33 patients experienced 1 or more therapy failures, resulting in a recurrence rate of 39%. Fifteen patients received a pectoralis muscle flap as definite treatment modality. ConclusionsImmediate primary closure is associated with a high rate of local infection recurrence. Surgical debridement and conditioning of the wound until resolution of infections with delayed primary closure or plastic reconstruction is suggested as the more appropriate treatment modality, with promising results.

Repair of stent graft-induced retrograde type A aortic dissection using the E-vita open prosthesis †

OBJECTIVES Stent graft-induced retrograde type A dissection is a life-threatening complication after endovascular treatment of acute aortic type B dissections. METHODS From August 2005 to February 2011, retrograde aortic dissection occurred in 4 of 29 patients (13.8%) undergoing thoracic endovascular aortic repair (TEVAR) for acute complicated aortic type B dissection. Three patients underwent emergent surgical conversion immediately after TEVAR. The operative strategy was a combined surgical and endovascular approach (frozen elephant trunk technique) using a specially designed hybrid prosthesis (Jotec E-vita open). All operations were performed under moderate hypothermia (25-28°C) and selective bilateral antegrade cerebral perfusion. The mean duration of circulatory arrest was 56 ± 7 min. Operative data and the outcome of surgery were analysed retrospectively. Data were analysed retrospectively in the limited number of patients. RESULTS All patients survived the surgical procedure. No stroke, paraplegia, renal failure or other major complications occurred. Postoperative CT scans revealed perigraft thrombus formation and stable aortic dimensions in all patients after 6 months. In one patient, the retrograde dissection remained primarily undetected and untreated. The patient died suddenly, with no clinical signs, within 7 days after stent graft implantation. Autopsy revealed cardiac tamponade due to retrograde type A aortic dissection. CONCLUSIONS Retrograde aortic dissection type A is a serious complication of thoracic endovascular repair of acute aortic type B dissection. Despite the small number of patients investigated in this study, the frozen elephant trunk technique appears to be a feasible bail-out strategy for the treatment of these acute aortic events.

Fate of the False Lumen After Combined Surgical and Endovascular Repair Treating Stanford Type A Aortic Dissections

BACKGROUND The purpose of this study was to evaluate the alterations of the aorta by using a new combined surgical and endovascular technique for the treatment of aortic type A dissections. The diameter of the descending aorta, the implanted stent graft, and the false lumen were evaluated. METHODS Between August 2005 and February 2009, 14 patients (aged 49 +/- 13 years; 11 men, 3 women) with type A dissection in the aorta were operated on the thoracic aorta by the frozen elephant trunk technique. The size dynamics of the false lumen were analyzed by deducting the diameter of the stent graft obtained on computed tomography from the maximum dimension of the aorta. RESULTS The technical success rate was 100%. All patients survived during the follow-up period. The mean follow-up period was 21.4 months. No redisection or aortic rupture occurred during the follow-up period. Postoperative computed tomography scans showed complete thrombus formation of the false lumen in the perigraft space within the entire zone of the stented segment of the hybrid prosthesis during the first 2 weeks after surgery in 12 patients (86%), whereas all patients showed complete obliteration of the false lumen at the 3-month control. The follow-up computed tomography scan obtained after 12 months revealed shrinkage of the false lumen in 9 patients (64%). CONCLUSIONS The combined surgical and endovascular technique described in this report proved effective for the treatment of extended aortic lesions. The perigraft space thrombosed completely and had shrunken after successful placement of the stent graft.