Open surgical secondary procedures after thoracic endovascular aortic repair.

OBJECTIVES: Improved outcomes of thoracic endovascular aortic repair (TEVAR) compared with open repair have changed the therapeutic paradigm of thoracic aortic lesions. As the number of TEVAR survivors has grown, reports of complications have similarly increased. Although secondary endovascular rescue measures are often undertaken, patients with serious complications are often converted, ultimately, to open repair. The aim of this study was to assess causes and midterm results of open surgical secondary procedures after thoracic endovascular aortic repair. METHODS: A total of 236 patients underwent TEVAR. Fourteen of these patients required open repair because of six aortobronchial fistulas, four retrograde type A dissections, two aneurysm enlargement without endoleak, one thoracic stent-graft collapse, and one aortoesophageal fistula. Eight (57.1%) patients underwent surgical repair using cardiopulmonary bypass. Six stent-grafts were totally removed, and eight stent-grafts were left in situ. Four patients underwent supracoronary ascending aorta replacement, and one an extensive replacement of the aortic arch through sternotomy. Three patients had descending aortic replacement through left thoracotomy combined with a total esophagectomy in one case. One patient was treated by ligation of the aortic arch, ascending to supraceliac abdominal aorta bypass and stent-graft explantation. One patient was treated by exclusion bypass of the descending thoracic aorta. Pulmonary resection and large pleural or intercostal muscle flap interposition to wrap the stent-graft left in situ was done in four cases of aortobronchial fistula. RESULTS: All patients survived the surgical procedure. Ten patients (71%) had an uneventful postoperative course. There were two in-hospital deaths (14.3%). Both died from multi-organ failure in the early postoperative course after surgical repair of a stent-graft infection and an aortoesophageal fistula. One patient suffered a definitive paraplegia and a secondary aortoesophageal fistula requiring reoperation for esophageal repair. One patient, treated by pulmonary resection and flap interposition to wrap the stent-graft, underwent stent-graft explantation and in situ descending aortic replacement because of stent-graft reinfection. Actuarial survival was 87.7% after a mean follow-up of 26.3 months (range 9-72 months). CONCLUSIONS: Complications or prevention of complications after TEVAR either due to device failure or adverse events may require conversion to open repair or additional open surgical procedure. Open repair can be performed by a team experienced in management of diseases of the thoracic aorta and a low mortality rate achieved despite the precarious preoperative conditions and complex aortic pathologies of patients.

Persistent contamination of heater-cooler units for extracorporeal circulation cured by chlorhexidine-alcohol in water tanks.

Recently, surgical site infections due to non-tuberculous mycobacteria (NTM) have been linked to heater-cooler unit contamination. The European Centre for Disease Prevention and Control and manufacturers now recommend the use of hydrogen peroxide in filtered water to fill heater-cooler unit tanks. After implementation of these measures in our hospital, heater-cooler units became heavily contaminated by opportunistic waterborne pathogens such as Pseudomonas aeruginosa and Stenotrophomonas maltophilia. No NTM were detected but fast-growing resistant bacteria could impair their detection. The efficiency of hydrogen peroxide and chlorhexidine-alcohol was compared in situ. Chlorhexidine-alcohol treatment stopped waterborne pathogen contamination and NTM were not cultured whereas their detection efficiency was probably improved.

Voltage-gated calcium channel currents in human coronary myocytes. Regulation by cyclic GMP and nitric oxide.

Voltage-gated Ca2+ channels contribute to the maintenance of contractile tone in vascular myocytes and are potential targets for vasodilating agents. There is no information available about their nature and regulation in human coronary arteries. We used the whole-cell voltage-clamp technique to characterize Ca2+-channel currents immediately after enzymatic dissociation and after primary culture of coronary myocytes taken from heart transplant patients. We recorded a dihydropyridine-sensitive L-type current in both freshly isolated and primary cultured cells. A T-type current was recorded only in culture. The L- (but not the T-) type current was inhibited by permeable analogues of cGMP in a dose-dependent manner. This effect was mimicked by the nitric oxide-generating agents S-nitroso-N-acetylpenicillamine (SNAP) and 3-morpholinosydnonimine which increased intracellular cGMP. Methylene blue, known to inhibit guanylate cyclase, antagonized the effect of SNAP. Inhibitions by SNAP and cGMP were not additive and seemed to occur through a common pathway. We conclude that (a) L-type Ca2+ channels are the major pathway for voltage-gated Ca2+ entry in human coronary myocytes; (b) their inhibition by agents stimulating nitric oxide and/or intracellular cGMP production is expected to contribute to vasorelaxation and may be involved in the therapeutic effect of nitrovasodilators; and (c) the expression of T-type Ca2+ channels in culture may be triggered by cell proliferation.

[Visceral artery aneurysms. Multiple aneurysmal localization: a case report and literature review]. / Les anévrismes des artères digestives. A propos d'un cas clinique de localisation anévrismale multiple et revue de la littérature.

Visceral artery aneurysms constitute a rare vascular disease, with a risk of rupture associated to a high mortality. Often asymptomatic, they are discovered following a routine radiological examination. We present the case of a 71-year-old patient with multiple aneurysms involving the celiac trunk, the splenic artery, and the common hepatic artery. The surgical treatment consisted of an aortohepatic bypass using polytetrafluoroethylene prosthesis, after exclusion of all the aneurysms. The angiography and postoperative angioscan demonstrated the perfect patency of the prosthesis, totally excluding the aneurysms. Given the variety of presentations and the absence of precise predictive factors, there is no therapeutic consensus so far. Surgery is the first therapeutic choice. Endovascular treatment by angioembolization must be reserved for particular conditions. The purpose of this article is to propose the best therapeutic approach on the basis of evidence in the literature.

[Detection and surgical treatment of induced ventricular tachycardia in postinfarction left ventricular aneurysm].

A clinical case of a patient aged 56 years with postinfarction left ventricular aneurysm not complicated with ventricular tachyarrhythmias is presented electrophysiological investigation. Left ventricular aneurysmectomy supplemented with endocardial cryodestruction was carried out. At electrophysiological investigation after surgery ventricular tachycardia could not be induced. In 2 years postoperatively no ventricular tachyarrhythmias were noted. The condition of the patient is satisfactory, corresponds to NYHA class I.

[Surgery of ventricular tachycardia in post-infarction left ventricular aneurysm]. / Chirurgie des tachycardies ventriculaires sur anévrismes ventriculaires gauches post-infarctus.

The treatment of post-infarction ventricular tachycardias with antiarrhythmic drug therapy, implantable automatic defibrillators, radiofrequency ablation, also includes different surgical procedures such as endocardial resection of the infarct scar, encircling endocardial ventriculotomy and endocardial cryoablation or thermoexclusion by laser. These procedures may be extensive or limited, guided or not by preoperative mapping. The aim of this review of the literature is to update our knowledge of these different surgical techniques and to define their indications.

Recurrence of postoperative aortic fistulas: is there an ideal method of prevention? A case report.

There are very few cases in English literature of recurrent postoperative aortic fistulas (RPAFs). These are neo-communications between the aortic bloodstream and the lumen of contiguous organs which occur after unpredictable periods from surgical treatment of a previous fistula. The supradiaphragmatic aorta may fistulize into the airways, pulmonary circulation, oesophagus, and cardiac chambers; the infradiaphragmatic aorta into the intestine, stomach, and vena cava. According to the etiology, aortic fistulas are categorized as postoperative (or secondary) and spontaneous (or primary), and RPAF may be considered a subgroup of secondary fistulas. They may recur even more times in the same patient, hence the role of prevention is of the utmost importance. The simultaneous respect of different surgical principles is crucial to make the risk of recurrence less likely. Surgical treatment represents a real challenge due to the emergency conditions and redo nature of operations. Mortality rate is very high. In this article, we describe a case of recurrent aorto-duodenal communication, we discuss the principles of prevention both for the supra and infradiaphragmatic aorta, we introduce some modifications to the classic categorization and we present the first RPAF literature review.

High prevalence of small dense LDL as an underestimated component of heart transplantation-induced dyslipidemia: potential role in graft coronary vasculopathy?

Heart transplantation-induced dyslipidemia is a recognized risk factor for cardiac allograft vasculopathy that affects survival prognosis. Beyond increased lipids, low-density lipoprotein (LDL) size and systemic factors, including glucose intolerance, oxidative stress, and inflammation, must be taken into account as components of the atherosclerotic risk. The aim of this study was to explore the atherogenic profile of heart transplant recipients (HTR) by assessing lipid parameters, glycemia, oxidative stress status, and inflammation in 59 transplant patients (follow-up of 6 +/- 3 years) compared to 20 healthy volunteers. Classical hypercholesterolemia and hypertriglyceridemia were observed in HTR compared to controls, associated with increased apoCIII levels (0.13 +/- 0.6 vs 0.07 +/- 0.03 g/L, P < .01). Mean LDL size was reduced in HTR compared to controls (25.22 +/- 0.72 vs 26.06 +/- 0.54 nm, P < .001) with an abnormally high prevalence (69% vs 0%, P < .001) of small dense LDL (<25.5 nm). Hyperglycemia (7.3 +/- 3 vs 5.4 +/- 0.8 mmol/L, P < .05) and inflammation (high-sensitive CRP: 3.1 +/- 3 vs 1.6 +/- 0.9 mg/L, P < .001) were evidenced in HTR since no difference in oxidative stress parameters was observed. In conclusion, a high prevalence of small dense LDL is an important component of posttransplantation dyslipidemia.

Cyclosporin A increases basal intracellular calcium and calcium responses to endothelin and vasopressin in human coronary myocytes.

Cyclosporin A (CsA) is a widely used immunosuppressive agent with severe side effects including hypertension. Here, we investigated the effects of CsA on intracellular free calcium ([Ca(2+)](i)) and the mechanisms involved in vasoconstriction in cultured human coronary myocytes. We used the Fura-2 technique for Ca(2+) imaging. Acute application of CsA at therapeutic concentrations (0.1-10 micromol/l) had no effect. Chronic exposure to CsA (1 micromol/l) for 24 h induced a small (20 nmol/l) but highly significant increase of basal [Ca(2+)](i) and enhanced the occurrence of spontaneous Ca(2+) oscillations. Endothelin- and vasopressin-induced rises of [Ca(2+)](i) were also enhanced. The demonstration that CsA increases basal [Ca(2+)](i) in addition to its impact on agonist receptor stimulation is of major importance for new therapeutic approaches.

Direct current catheter ablation of an accessory pathway in a recipient with refractory reciprocal tachycardia.

A recurrent reciprocating tachycardia developed in a 45-year-old man 2 years after heart transplantation. Electrocardiograms of both donor and recipient were normal, without patent preexcitation. An electrophysiologic study showed a left-sided Kent bundle with only retrograde conduction property. Because antiarrhythmic therapy was unsuccessful, direct current catheter ablation was performed. Since this procedure the patient remained asymptomatic without antiarrhythmic therapy.

Prognostic value of myocardial lactate dehydrogenase subunit ratio in heart transplant recipients.

BACKGROUND: Allograft coronary artery disease (CAD) is a major long-term complication in heart transplant recipients. Unfortunately, methods for early estimation of the likelihood of development of the disease are not currently available. Lactate dehydrogenase (LDH) is composed of heart and muscle subunits. The prevalence of these subunits in LDH isoenzymes (LDH1 through LDH5) is an accurate indicator of myocardial metabolism and allows indirect estimation of oxygen availability to cardiocytes. This study investigated the prognostic value of myocardial LDH composition for the occurrence of morbid events in patients with severe allograft CAD. METHODS: Eighty-eight heart transplant recipients were followed up for a median of 4.3 years. The isoenzymes of LDH and the ratio of the heart and muscle subunits (H/M) were determined in 526 endomyocardial biopsy samples. RESULTS: Eleven patients (12%) died from allograft CAD during follow-up. They had significantly lower H/M ratios compared with event-free patients, with clear differences as early as 6 months after operation. A threshold value of 2.75 was derived from receiver operating characteristic curve analysis. Patients showing H/M values < or =2.75 had a significantly higher mortality rate than did those with higher values (p=.0003). Importantly, the H/M ratio emerged as the most powerful independent prognostic factor of death by allograft CAD (p=.001) in a multivariate model. CONCLUSIONS: Poor myocardial aerobic metabolism estimated through low H/M values was highly predictive of cardiac death resulting from severe allograft CAD. Analysis of LDH isoenzyme profile in routine endomyocardial biopsies might be of clinical value.

Myocardial lactate dehydrogenase subunit ratio in cardiac allograft recipients.

BACKGROUND: Allograft coronary artery disease (CAD) is a major long-term complication in heart transplanted patients. However, the metabolic basis of allograft CAD remains to be fully elucidated. We analyzed the lactate dehydrogenase heart (H) and muscle (M) isoenzyme pattern in endomyocardial biopsy specimens and the evolution of the H/M ratio to test whether changes in this ratio could be the earliest manifestation of allograft CAD. METHODS: Twenty-four heart transplant recipients were followed up for 12 months. Endomyocardial biopsy was performed at 1, 2, 3, 6, and 12 months after transplantation. Lactate dehydrogenase 1 through 5 isoenzymes were separated by electrophoresis, and the H/M ratio was calculated. Two groups of patients were identified: group 1 (n = 20), patients without allograft CAD; and group 2 (n = 4), patients with poor outcome (three deaths, 1 case of low cardiac output) and angiographic and histologic evidence of allograft CAD. RESULTS: Both groups had similar H/M baseline values. The H/M ratio was higher (p = 0.01) in group 1 at 6 months (3.48 +/- 0.64 versus 2.17 +/- 0.43) and 12 months (3.76 +/- 0.92 versus 2.18 +/- 0.45) when compared with group 2. The H/M ratio increased from 2.78 +/- 0.89 at 1 month to 3.76 +/- 0.92 at 12 months (p = 0.02) in group 1 and decreased in group 2 (2.86 +/- 0.49 versus 2.18 +/- 0.45; not significant). CONCLUSIONS: Changes in H/M ratio reflect an anaerobic shift in the lactate dehydrogenase isoenzyme composition and can be taken as an early indicator of allograft CAD.

Autologous peripheral blood stem cell transplantation following heart transplantation for primary systemic amyloidosis.

A 47 years old woman was admitted with severe congestive heart failure. Cardiac echography showed increased intra-ventricular septum thickness, and there was a serum Ig G lambda monoclonal component. Cardiac biopsies confirmed diffuse amyloidosis of Al type. To avoid cardiac toxicity of chemotherapy, the patient received first a heart transplantation (HT), followed six months later by melphalan 200 mg/m(2) and autologous peripheral blood stem cell support (PBSCT). This case suggests that such strategy is feasible with a favorable outcome, and HT may be an appropriate procedure for some patients with Al amyloidosis who meet the criteria for PBSCT.

Exercise tolerance in heart transplant patients with altered pulmonary diffusion capacity.

To test whether orthotopic heart transplant (OHT) patients with low pulmonary diffusion capacity have a greater limitation to exercise than OHT patients with normal pulmonary diffusion capacity, we investigated cardiorespiratory responses and blood gases in two groups of OHT patients, one with low (LdG) and the other with normal pulmonary diffusion capacity (NdG), during a graded exercise test. The results showed 1) significantly reduced peak power (P < 0.05), peak oxygen uptake (VO2, P < 0.001), peak oxygen pulse (VO2/heart rate, P < 0.01), peak minute ventilation (VE, P < 0.05), and delta PaO2 (peak PaO2 - rest PaO2, P < 0.05) in LdG versus NdG; 2) a nonsignificant decrease in peak heart rate in LdG (P < 0.13, P = 24%); and 3) significant increases in peak respiratory equivalent for oxygen (VE/VO2, P < 0.05) and delta P(A-a)O2 (peak P(A-a)O2 - resting P(A-a)O2, P < 0.05) in LdG versus NdG. No significant difference was found for PaO2 and PaCO2 at rest or at peak exercise between the groups. A strong correlation was found between pulmonary diffusion capacity (TLCO/VA) and peak VO2 (r = 0.81, P < 0.01); that is, TLCO/VA explains 66% of the variance in peak VO2. We conclude that OHT patients with decreased pulmonary diffusion capacity have a lower exercise tolerance than patients with normal pulmonary diffusion capacity. However, because of the lack of exercise-induced hypoxemia, diffusion abnormalities are not the main limiting factor for exercise tolerance in the low diffusion group.

Influence of post-surgery time after cardiac transplantation on exercise responses.

Influence of post-surgery time after cardiac transplantation on exercise responses. Med. Sci. Sports Exerc., Vol. 28, No. 2, pp. 171-175, 1996. To test the hypothesis that exercise response changes with time after cardiac transplantation, we investigated the cardiorespiratory responses of nine orthotopic heart transplant patients (52.4 +/- 2 yr) during graded exercise tests (30 W.3 min-1) done at 1, 3, 6, 9 and 12 months post-surgery. At peak exercise, 1) oxygen uptake per kg of body weight (VO2), minute ventilation (VE) and oxygen pulse (O2 pulse) did not change significantly between 1 and 12 months postsurgery; 2) transplanted heart rate (HRt) and delta heart rate (peak exercise heart rate--resting heart rate) increased significantly over time (P < 0.01; P < 0.05) with a marked increase between 1 and 3 months (P < 0.05); and (3) a significant negative correlation existed between O2 pulse and HRt (r = -0.36, P < 0.05), whereas no correlation was found between delta heart rate and delta VO2 (peak exercise VO2- resting VO2, l.min-1). During submaximal exercise, HRt increased significantly over time (P < 0.001); VO2, VE, and O2 pulse showed no significant change; and the VO2-HRt relationship shifted toward higher values of HRt. We conclude that, in the absence of formal physical training, the exercise response of denervated transplanted heart increases in relation to post-surgery time but does not affect oxygen uptake at submaximal and peak levels of exercise.

Long term follow up of 292 patients after valve replacement with the Omnicarbon prosthetic valve.

In a prospective study, 292 consecutive patients received 336 Omnicarbon cardiac valves from September 1984 through September 1992 at the Montpellier University Hospital. There were 153 aortic (52%), 95 mitral (33%) and 44 double (15%) mitral and aortic replacements. Mean age was 58 years; 57% were male. Total follow up was 1,383 patient-years, with a maximum of nine and a mean of 4.87 years. Early mortality was 2.75% overall. Late mortality occurred at a rate of 1.9%/patient-year. Nine-year probability of freedom from mortality (including early mortality) was 85.0% +/- 2.6% overall. There were no cases of structural failure. Thromboembolic events occurred in nine patients, producing a linearized rate of 0.7%/patient-year. Hemorrhage associated with anticoagulant therapy occurred at a rate of 0.8%/patient-year. Therefore, the combined rate of thromboembolic/hemorrhagic events was 1.5%/patient-year. Cumulative overall freedom from thromboembolism and hemorrhage was 91.5% +/- 1.9% at nine years; it was 86.2% +/- 4.3% after mitral and 95.1% +/- 2.0% after aortic valve replacement. Hemolytic anemia was not observed. Endocarditis occurred eight times (0.6%/patient-year), and there were seven cases of perivalvular lead (0.5%/patient-year). At the end of the follow up, 86% of the patients were in NYHA class I. It is concluded that clinical results over a nine-year period are excellent with the Omnicarbon prosthesis.

False aneurysm of the ascending aorta following aortic valve replacement.

False aneurysm of the ascending aorta is a rare and life-threatening complication of open heart surgery, usually occurring late after operation. Echocardiography, especially transesophageal echocardiography, is a non-invasive method of examination which can be very helpful in its diagnosis. Deep hypothermia and circulatory arrest allow a bloodless field during surgery and provide an adequate patient protection. Infection is a very well known predisposing factor, but cystic medial necrosis of the aortic wall also seems to play a role in this complication. We report three cases, two of them had cystic medial necrosis and the presence of infection could be proved in none.

Aspergillus flavus mitral valve endocarditis after lung abscess.

A 16-year-old male with bone marrow failure due to chemotherapy for recurrent acute lymphoblastic leukemia developed an abscess in the lower lobe of the left lung draining through a bronchogastric fistula, as well as mitral valve endocarditis with large vegetations. After a course of antifungal therapy, the left lobe was removed and the fistula closed. The mitral valve was then replaced, after a failed attempt at valve repair, by a mechanical, double-leaflet prosthesis. Microscopy of the lung and heart specimens disclosed hyphae. Cultures of both specimens on Sabouraud's medium recovered a fungus, which was identified by culturing on Czapek's medium as Aspergillus flavus. Despite further antifungal therapy, fatal embolism developed. The emboli contained the same A. flavus as the valve and lung specimens. This case confirms the grim prognosis of primary Aspergillus endocarditis in immunocompromised patients, and suggests that delayed surgical treatment and the presence of another focus of Aspergillus infection may increase the risk of death.

Necrotic skin lesions in a dialysis patient: a multifactorial entity.

A female dialysis patient with a consistently high serum calcium phosphate product presented with large necrotic skin lesions with ulcers. The clinical course was highly suggestive of calciphylaxis. Parathyroidectomy was followed by the healing of the lesions. New skin lesions appeared following relapse of hyperparathyroidism. Her clinical records included a long past of hypertension, which was the cause of her renal failure. She had a limited walking range and previously had presented bilateral ulcers of vascular origin. This case presents a type of lesion which bears a serious prognosis in dialysis patients. The clinical context and the presentation of the lesions are compatible with multiple etiology: vascular lesions and calciphylaxis. The documented longitudinal follow-up illustrates the importance of treating the different factors known to participate in the appearance of skin lesions in dialysis patients. Particularly, it stresses the benefit of performing parathyroidectomy, even if the parathyroid hormone level is not in the range normally accepted as requiring surgical removal of parathyroid glands.

Dissecting aneurysms of the ascending aorta occurring late after aortic valve replacement.

In 4 patients who had undergone aortic valve replacement, a dissection of the ascending aorta appeared between 7 and 16 years later (mean 12 years). This is a rare complication, occurring in less than one percent of cases. Three cases of aortic regurgitation and one of aortic stenosis developed, and 3 of the cases had dilatation of the ascending aorta and hypertension. The symptoms of dissection were accompanied by signs of either the superior vena caval syndrome or compression of the pulmonary artery. The diagnosis was confirmed by echography and by CT scan. Despite the advances made in the surgery of dissection the prognosis was serious, and 2 of the 4 patients died. Avoidance of this complication depends on replacement of the ascending aorta (composite tube or supracoronary graft according to the involvement of the sinuses of Valsalva) as soon as the diameter of aorta exceeds 55 mm. In cases of moderate dilatation (45-50 mm), systemic reinforcement with Dacron mesh has been shown to have long-term effectiveness.