Increased cardiovascular comorbidities in patients with myelodysplastic syndromes and chronic myelomonocytic leukemia presenting with systemic inflammatory and autoimmune manifestations.

Myelodysplastic syndromes (MDS) and associated diseases, like chronic myelomonocytic leukemias (CMML), are heterogeneous, clonal disorders affecting the hematopoietic stem cells. They are characterized by dysplasia and a propensity to evolve toward acute myeloid leukemia. Systemic inflammatory and autoimmune manifestations (SIAMs) occur with a prevalence of 10% to 20% in myeloid malignancies, but the underlying pathogenetic mechanisms remain obscure. In this study, we aimed to characterize patient- and disease-based differences in MDS and CMML patients with and without SIAMs and explore the impact of SIAMs on progression and survival. We performed a retrospective, single-centre, and case-control study in a cohort of 93 patients diagnosed with MDS and CMML between 01/2008 and 12/2015. Thirty patients (32%) were identified with SIAMs: musculoskeletal and connective tissue (26.8%), vascular (19.5%), systemic autoinflammation (17%), skin (12.2%), gastrointestinal (9.8%), and others (14.6%). SIAMs were treated with glucocorticoids (60%), methotrexate (16.7%), biologicals (13.3%), and cyclosporine (3.3%). No significant differences between the SIAM and non-SIAM patients were observed in age, gender, or previous exposure to cancer treatment. Cardiovascular comorbidities were significantly more frequent in patients with SIAMs (63.1% vs 90%; OR 5.5; P < .01), but no differences were observed for other comorbidities or IPSS and IPSS-R risk scores. CMML and refractory anemia with excess blasts 1/2 subtypes were by tendency more frequent in patients with and refractory cytopenia with multilineage dysplasia (RCMD) in those without SIAMs. Finally, time to progression, leukemia free survival and overall survival were similar for both groups. Despite patient heterogeneity and small cohort size, we were able to identify a significant association of SIAMs with cardiovascular comorbidities but without influence on progression or survival.

[The Sorin pericardial bioprosthesis--a stentless aortic valve with very good hemodynamic performance]. / Die Sorin Perikard-Bioprothese--eine Stentless Aortenklappe mit sehr guter hämodynamischer Leistung.

BACKGROUND: The Sorin Pericarbon Freedom Stentless aortic valve has the potential to provide superior hemodynamic function and durability. In this study we assessed the hemodynamic performance of this valve and its impact on LV-mass regression after aortic valve replacement. METHODS: 31 consecutive patients who received a Sorin Pericarbon Freedom Stentless aortic valve were analysed. Mean age of the patients (16 female and 15 male) was 64 +/- 17 years. Five patients had isolated aortic stenosis, three isolated aortic regurgitation and one combined aortic valve disease. Three patients had combined aortic and mitral valve disease, 14 patients concomitant coronary artery disease, one congenital aortic coarctation. Three patients had an acute aortic valve endocarditis. 18 patients were classified as high-risk patients (mean EuroSCORE 9 +/- 2). Mean left ventricular ejection fraction was 52.5 +/- 15.0%. RESULTS: Valve sizes from 21 mm to 29 mm were implanted. The valves were oversized by 2 mm compared to measurement. 16 patients received isolated aortic valve replacement, Three patients aortic valve replacement and mitral valve reconstruction. 12 patients had concomitant CABG. Three procedures were reoperations. Hospital mortality was 6.4% (two patients). Both deaths occurred in high-risk patients and were not valve-related. Four patients had perioperative low-output-syndrome and needed IABP. After six months a follow up echocardiography was performed. Mean and peak gradients were 9.6 +/- 4.4 and 20.6 +/- 5.9 mmHg, respectively. Significant reduction of left ventricular hypertrophy (LV mass index 126.5 +/- 27.3 vs. 189.6 +/- 45.3 g/m2, p = 0.0313) and improvement of the ejection fraction (58 +/- 9.8 vs. 52.5 +/- 15.0%, p = 0.9749) as compared with preoperative valve. CONCLUSIONS: The hemodynamic performance of the Sorin Pericarbon Freedom Stentless aortic valve is excellent and the patient outcome is satisfying. However the implantation technique requires longer ischemic time, the prosthesis offers very satisfying hemodynamic function and accelerates probably the LV-mass regression in the mid term follow-up. Late performance and durability of the valve have to be assessed.

The reversed and bidirectional elephant trunk technique in the treatment of complex aortic aneurysms.

BACKGROUND: The elephant trunk technique with a free-floating vascular prosthesis was originally developed to facilitate a subsequent operation on the downstream aorta. We present here our experience with further developments of this technique, which we call the reversed elephant trunk and bidirectional elephant trunk. METHODS: Between January 1, 1995, and December 31, 2000, 505 adult and adolescent patients underwent operations of the thoracic aorta. A reversed elephant trunk procedure in 13 patients and a bidirectional elephant trunk procedure in 4 patients was performed to facilitate either subsequent proximal or proximal and distal aortic replacement. Nine patients underwent subsequent aortic arch replacement with the reversed prosthetic portion after a mean interval of 8 +/- 5.5 months, and 2 patients received distal extension by use of the distal portion of the free-floating graft. RESULTS: There was no hospital mortality (30 days) in this small group of patients, and no patient had aortic rupture, malperfusion caused by the technique itself, or thromboembolic complications during the waiting interval between the first and the second operations. Five patients are still being observed until the contiguous aortic size is large enough to require an operation, and one 74-year-old patient declined a second-stage operation. CONCLUSION: The reversed and bidirectional elephant trunk techniques are interesting options that may be suitable for patients having complex abnormalities of the thoracic aorta and thoracoabdominal aorta when the proximal portion of the descending aorta has to be replaced before the aortic arch with or without the ascending aorta or the distal descending aorta with or without the thoracoabdominal aorta.

Determination of plasma volume by indocyanine green--validation of the method and use in patients after cardiopulmonary bypass.

OBJECTIVE: Validation of plasma volume (PV) determination by indocyanine green (ICG) in comparison to the gold-standard method with radioiodinated albumin, and investigation of the effect of commonly used plasma expanders (albumin, hydroxyethyl starch, and polygelatine) on PV in the early postoperative phase in patients undergoing cardiac surgery. DESIGN: Prospective clinical study. SETTING: Department of medicine and intensive care unit at a university hospital. PATIENTS AND PARTICIPANTS: Ten healthy volunteers and 21 patients after elective open-heart surgery. MEASUREMENTS AND RESULTS: PV of subjects was measured by i.v. injecting 5 microCi [125I]albumin (I-ALB). One hour later, PV was determined by a peripheral i. v. injection of 0.25 mg/kg body weight ICG (ICG1). In five subjects PV was measured repeatedly by ICG (ICG2) 1 h after ICG1. Mean PV of I-ALB and ICG1 or ICG2 showed consistent results. Further, we investigated central vs peripheral intravenous injection of ICG in six patients after open-heart surgery compared to [125I]albumin. There was no difference between mean PV measured by [125I]albumin and peripheral ICG (P = 0.40). PV determined by central injection of ICG was significantly higher than by the other methods. In 15 patients PV was determined by [125I]albumin. Thereafter, patients were randomly divided into three groups. Group ALB was infused with 1.75 ml/kg body weight human albumin 20%, group HAES with 5.25 ml/kg body weight hydroxyethyl starch 6%, and group HAEM with 7.0 ml/kg body weight polygelatine 3.5%. PV was measured 1 h and 4 h after infusion by ICG. There were no significant changes in PV between the groups. CONCLUSIONS: PV determination by peripheral i. v. injection of ICG produced reliable and consistent results when a reactive hyperaemia was produced by a tourniquet prior to injection. Therefore, central venous injection of ICG may not be prerequisite for precise measurements of PV. The expected acute increase in PV after infusion of commonly used plasma expanders after cardiac surgery was not found.

Embolization of a ruptured intercostal artery aneurysm in type I neurofibromatosis.

We present the case of a female with history of a ruptured lumbar aneurysm years ago. She was known to have neurofibromatosis type I with the typical clinical signs. The patient was transferred to us with a hematothorax and an aortic lesion was suspected on the outside CT scan. Reevaluation of the investigation raised suspicion of a ruptured intercostal artery aneurysm, which was consequently demonstrated on angiography. The aneurysm was embolized and the patient recovered uneventful. We will discuss the optimal therapy for vessel lesions in neurofibromatosis type I.

Rare presentation of cardiac hemangiomas.

Cardiac hemangiomas are exceptionally rare tumors with an incidence of 1% to 2% of all detected benign heart neoplasms. The clinical appearance of the tumor varies considerably and may mimic other pathological findings of definite heart structures. We report two cases of cardiac hemangiomas presenting with an unusual location and clinical course.

Outcome of thoracoabdominal aortic operations using deep hypothermia and distal exsanguination.

BACKGROUND: Operation of the descending and thoracoabdominal aorta may be affected by a significant perioperative morbidity, mainly because of ischemic damage of the spinal cord and malperfusion of the abdominal organs. METHODS: A comparative analysis was performed on two consecutive series of patients operated between 1982 and 1998. Group 1 consisted of 90 patients operated with moderate hypothermic left heart bypass. Group 2 included 38 patients operated using deep hypothermic cardiopulmonary bypass and a period of circulatory arrest while performing the proximal anastomosis and distal exsanguination during confection of the distal anastomosis. RESULTS: Main demographic factors and causes of the aortic disease were similar in both groups. Early mortality was significantly higher in the group of patients with aortic cross-clamping (15 of 90, 16%) than in those operated with circulatory arrest (2 of 38, 5.2%), p < 0.001. Paraplegia occurred in 8 patients in the group operated with mild hypothermia (8.8%) but in only 1 patient (2.6%) when deep hypothermia had been used. CONCLUSIONS: In our experience, deep hypothermia combined with distal exsanguination significantly improved the early postoperative outcome after operation of the descending and thoracoabdominal aorta. This technique allowed easy confection of proximal and distal anastomoses, and the duration of the operation was not prolonged significantly through this approach.

[Cryopreserved arterial homografts. A treatment alternative for infected vascular reconstructions]. / Kryopräservierte arterielle Homografts. Therapeutische Alternative bei tiefer Gefässinfektion.

Deep wound infection or prosthetic vascular graft infection is one of the most challenging complications in vascular surgery with a substantial early and late morbidity and mortality. Surgical treatment usually consists of complete removal of infected vessels or prosthetic vascular grafts followed by extraanatomic bypass procedures. However, this method is associated with significant mortality and amputation rates. Herein, we report two patients with deep wound and prosthetic vascular graft infection who underwent successful in situ reconstruction with cryopreserved arterial homografts. Although the long-term results are missing, this approach may offer a possible treatment alternative for this potentially life-threatening complication.

Evaluation of coronary bypass flow with color-Doppler and magnetic resonance imaging techniques: comparison with intraoperative flow measurements.

OBJECTIVES: After coronary artery bypass surgery, patency and flow assessment is based on invasive methods such as angiography and intravascular ultrasound or flow wire techniques. The aim of the study was to compare intraoperative transit time flow measurements of coronary bypass grafts with early postoperative color-Doppler and MR-imaging assessment. METHODS: In 22 patients (62+/-8.5 years) undergoing elective coronary bypass surgery the flow was measured in all internal mammary artery grafts (IMA) and saphenous vein grafts using the transit time flow technique. Postoperatively (days 5-7) all patients had a color-Doppler IMA graft assessment followed by a MR-angiography and flow measurement (navigator echo phase contrast technique with and without contrast bolus application) to determine patency and graft flow. RESULTS: Data are expressed as the mean +/- SD). (1) In all patients the left IMA graft to the left anterior descending coronary artery (LAD) could be identified and flow could be assessed with both color-Doppler and MRI. Venous grafts could only be visualized by MRI. The use of an intravenous contrast bolus enhanced the visualization of coronary artery bypass grafts. (2) The mean IMA to LAD flow was 33+/-17 ml/min intraoperatively by transit time and postoperatively 36+/-25 ml/min by MR respectively 66+/-54 ml/min by color-Doppler technique. (3) The systolic/diastolic flow ratio was 0.44+/-0.12 intraoperatively and 0.43+/-0.17 postoperatively by MR respectively 0.67+/-1.0 by color-Doppler. (4) A statistically significant correlation could be demonstrated between intraoperative transit time and postoperative MR flow measurements (r = 0.57; P < 0.04), whereas the correlations to color-Doppler flow were poor. Postoperatively MR and color-Doppler showed a good correlation of systolic/diastolic flow ratio (r = 0.88; P < 0.008). CONCLUSIONS: The color-Doppler method during echocardiography and MR-imaging are useful non-invasive techniques to visualize postoperative IMA grafts for patency assessment. The quantification of IMA flow is still difficult with either technique, but MR flow measurements showed the best correlation to the intraoperatively measured transit time flow. The MR technique is the most promising non-invasive method for postoperative evaluation of coronary bypass grafts, since it allows visualization and reliable flow quantification.

Intra- and postoperative quality control in minimally invasive direct coronary artery bypass (MIDCAB) surgery.

The introduction of new techniques allowing direct coronary artery revascularisation without sternotomy and extracorporeal circulation--called Minimally (or less) Invasive Direct Coronary Artery Bypass grafting (MIDCAB)--has opened up interesting perspectives for the treatment of patients with limited coronary artery disease. However, like any newer surgical technique, this approach to myocardial revascularisation requires a critical appreciation of the results which may be obtained; when introducing the MIDCAB technique in our institution we developed a quality control protocol based on intraoperative as well as early and late postoperative parameters. This protocol is designed to detect every significant adverse event, exercise capacity and quality of life of our patients. Moreover, several invasive parameters have to be recorded in the protocol, such as intraoperative flow in the internal mammary artery conduit, the angiographic verification of anastomotic patency at one-year follow-up and determination of coronary flow reserve. The results of the first 5 patients observed up to one year postoperatively are presented: all anastomoses were patent and the flow within the internal mammary artery was 69 +/- 40 ml/min at one-year follow-up angiography; this compares very favourably with the flow measured at the end of the operation, which was 31 +/- 8 ml/min. This demonstrates very clearly that internal mammary artery flow is recruitable and usually significantly increases within the first months postoperatively. Coronary flow reserve was 3.4 +/- 1.1 (normal value > 2.5). The results obtained in this pilot study, which was designed to establish a quality control protocol, are very satisfactory and confirm previous experience that this technique may be offered to selected patients with appropriate coronary anatomy.

Different techniques of distal aortic repair in acute type A dissection: impact on late aortic morphology and reoperation.

OBJECTIVE: To compare three different techniques of distal aortic repair in acute type A (de Bakey type I) aortic dissection and to evaluate their impact on the late morphology of the aortic arch and descending aorta and on the incidence of reoperation. METHODS: From 65 patients operated on due to an acute type A aortic dissection between 1989 and 1993, 54 long-term survivors underwent clinical and radiologic follow-up examination after a mean postoperative interval of 62+/-16 months. The surgical techniques of distal aortic reconstruction included closed repair using Teflon felt reinforcement under moderate hypothermic cardiopulmonary bypass (n = 20) and open repair in deep hypothermic circulatory arrest using either Teflon felt reinforcement (n = 16) or gelatin-resorcin-formaldehyde (GRF) glue (n = 18) to readapt the dissected aortic layers. In all patients, MR imaging was performed on a 1.5-T whole body imaging system for the evaluation of the morphology and function of the heart, aorta and supraaortic branches. RESULTS: Overall hospital mortality following surgical repair of type A aortic dissection was 15.4% during this time period. The highest rate of persistent false lumen perfusion (17/20, 85%) and presence of an intimal flap in the aortic arch (13/20, 65%) was observed in patients following closed repair of acute ascending aortic dissection, whereas the lowest rate of such findings was demonstrated in patients who had undergone open distal aortic repair using biological glue (false lumen perfusion 10/18, 55% and intimal flap in the arch 2/18, 11%). Redo-surgery was significantly reduced in the open repair group using GRF glue (1/18, 5.5%) as compared with the Teflon felt repair group (3/16, 18%) and the closed repair group (6/20, 30%). CONCLUSIONS: In patients with acute type A dissection, open distal aortic repair using GRF-glue favourably influences both (1) the severity of late morphologic alterations in the downstream aorta and (2) the incidence of reoperation.

[Bj"ork-Shiley heart vales at the Bern University Hospital. Long-term follow-up of 12 to 23 years after mitral and aortic valve replacement in 503 patients]. / Björk-Shiley-Herzklappen im Universitätsspital Bern. Langzeit Follow-up 12 bis 23 Jahre nach Mitral- und Aortenklappenersatz bei 503 Patienten.

Long-term follow-up, cardial complications and factors influencing the survival time have been investigated retrospectively in 503 patients, who underwent 344 aortic and 191 mitral valve replacements with Björk-Shiley heart valve prosthesis between 1973 and 1984 at the University Hospital of Berne, Switzerland. Informations were assessed from the patient's files and a questionnaire to the family physician. The cumulative follow-up contains a total of 4,810 patient years or a median of 14 years per patient. The median survival time was 19 years, hardly less than the normal life expectancy. Of the 135 patients found alive in 1996 66% had no cardiac problems at all. Two cases of outlet strut fracture of the Björk-Shiley valve were reported during the follow-up time. Both patients had a mitral valve replacement in 1982 with a 31 mm Björk-Shiley valve because of mitral stenosis. The most common complication was a thromboembolic incident (1.6 in 100 patient years). Furthermore eight cases of valve thrombosis, 16 of endocarditis and 24 of myocardial infarction occurred in this population. The study showed that survival time after heart valve replacement with Björk-Shiley valve is long. The mortality was elevated significantly with the following preoperative findings: severe dyspnea (x 2.0), pulmonary congestion (x 1.7) and increased cardiac size (x 1.5). The survival time was shorter when a valve prosthesis with a diameter larger than 27 was used or when in addition coronary heart disease, hypertension, diabetes mellitus or obesity were present.

[Conventional heart surgery with the fast-track-method: experiences from a pilot study]. / Konventionelle Herzchirurgie im Fast-track-Verfahren: Erfahrungen aus einer Pilotstudie.

Early release after cardiac surgery can be promoted by implementation of a standard protocol for accelerated perioperative and early postoperative care, with optimal education and support of the patient playing a key role. We report on our preliminary experience with 100 selected patients who underwent a "fast track" protocol following coronary artery bypass (n = 61), valve replacement or reconstruction (n = 34) or closure of an atrial septal defect (n = 5) between 1996 and 1998. Surgery was performed through a midline sternotomy using normothermic or mild hypothermic cardiopulmonary bypass. Patients undergoing cardiac surgery with less invasive techniques were excluded from this study. The following criteria had to be fulfilled for early hospital discharge: sinus rhythm, temperature below 37.5 degrees C, stable haematocrit around 0.30, uncomplicated wound healing and complete mobilisation including stair exercises. Mean duration of the operation was 137 +/- 24 minutes and mean intubation time was 4.5 +/- 3 hours. Mean duration of hospitalisation from the day of the operation was 4.9 +/- 2.1 days. There was no early or late mortality in this group of patients and only 2 patients had to be re-admitted on postoperative day 10 and 14 because of atrial fibrillation in one and a wound healing problem in the other. Accelerated recovery and early hospital discharge is highly attractive in selected patients; in helps to promote early cardiac rehabilitation and the costs of the procedure can be substantially reduced. According to our experience and the most recent literature, this approach does not expose patients to higher mortality or morbidity. In addition, fast-tracked patients have shown a higher level of satisfaction. Under optimal cooperation between surgery, anaesthesiology and intensive care unit, the fast-track protocol can be applied in approximately 30% of overall adult cardiac surgery patients.

Failed coronary artery bypass anastomosis detected by intraoperative coronary flow measurement.

OBJECTIVES: To assess intraoperative flow of arterial and venous coronary grafts after myocardial revascularization which may allow early detection of low flow situations, especially during minimally invasive coronary bypass surgery (MIDCAB), and lead to immediate correction of technical problems. METHODS: In two patients with severe and diffuse multi-vessel disease the left internal mammary artery (IMA) was connected to the left anterior descending artery (LAD). During reperfusion, the flow was measured in the IMA and vein grafts using a transit time flow meter. RESULTS: In both cases the IMA showed only a systolic pendulating flow curve with a mean flow of 0-1 ml/min and a high resistance. Manual IMA assessment revealed an adequate pulsation. Both distal IMA anastomoses were re-explored on cardiopulmonary bypass yielding an initial flow of 7 and 14 ml/min, respectively. After treatment with papaverine/adenosine the IMA flow increased from 7 to 26 ml/min (coronary flow reserve (CFR) = 3.7) and from 14 to 46 ml/min (CFR = 3.3), respectively. CONCLUSION: Intraoperative flow assessment of IMA and venous bypass grafts can be recommended to monitor flow; especially during MIDCAB procedures.

Definitive cure of recurrent prosthetic endocarditis using silver-coated St. Jude Medical heart valves: a preliminary case report.

Despite progress in the area of antimicrobial treatment and the surgical use of homografts, prosthetic valve endocarditis (PVE) remains one of the most dangerous complications following heart valve replacement. We present the case of a patient treated for acute endocarditis which affected the mitral valve and who developed recurrent PVE and native aortic valve endocarditis. After multiple valve surgery, the infection was controlled following aortic and mitral valve replacement using silver-coated prostheses. The St. Jude Medical (SJM) mechanical heart valve Masters Series with Silzone coating is intended to protect heart valve patients against microbial infection. The Silzone coating is formed by an ion beam-assisted deposition process that incorporates silver into the sewing cuff of the SJM heart valve. It has also been suggested that silver treatment may improve the healing characteristics of the heart valve sewing cuff. This technology may be a valuable option to prevent or cure PVE, in addition to homografts. Although the present patient is an isolated case, it was encouraging to find not only a well-healed mitral valve silver-coated prosthesis but also no persistent or recurrent infection during a nine-month follow up.

Transit-time flow measurement for detection of early graft failure during myocardial revascularization.

BACKGROUND: A low-flow situation in arterial and venous grafts has been associated with high rates of perioperative infarction and mortality. This study was designed to look at intraoperative graft flow and resistance in patients with coronary artery disease. METHODS: Coronary artery bypass graft flow was measured in 46 patients. Transit-time flow was used for coronary flow measurements at rest as well as after maximal vasodilation with adenosine infusion. RESULTS: Forty-three of the 46 patients showed normal internal mammary artery graft flow (>20 mL/min); 3 patients had no or minimal graft flow. Redoing the graft anastomosis in these 3 patients resulted in normalization of graft flow. The mean flow increased significantly after correction from 0.5 +/- 0.7 mL/min to 15.7 +/- 9.6 mL/min (p < 0.02). Conversely, vascular resistance decreased significantly from 138 +/- 10 to 4.8 +/- 1.8 Ohmv (p < 0.0001), as did the pulsatility index (from 146.9 +/- 95.7 to 3.4 +/- 1.8; p < 0.001). After correction, coronary flow reserve was 2.5 +/- 1.1. CONCLUSIONS: Measurements of intraoperative flow and resistance as well as derived variables allow assessment of early graft function and thus help prevent graft failure and reduce perioperative infarction. Transit-time volume flow might be a simple tool for quality control in coronary bypass procedures.

Different proliferative properties of smooth muscle cells of human arterial and venous bypass vessels: role of PDGF receptors, mitogen-activated protein kinase, and cyclin-dependent kinase inhibitors.

BACKGROUND: Internal mammary artery (IMA) bypass grafts have a higher patency than saphenous vein (SV) grafts. Intimal hyperplasia of SV grafts is due to smooth muscle cell (SMC) proliferation and migration. We hypothesized that different SMC growth activity exists in IMA and SV, which may explain the different patencies of arterial and venous grafts. METHODS AND RESULTS: SMCs were isolated from IMA and SV by explant culture and stimulated with serum or platelet-derived growth factor-BB (PDGF-BB). Cell growth was analyzed by explant outgrowth rate, 3H-thymidine incorporation, or cell counting. PDGF receptor expression and autophosphorylation, regulation of mitogen-activated protein kinases (MAPKs), and cyclin-dependent kinase inhibitors (p27Kip1 and p21Cip1) were analyzed by molecular techniques. SMC outgrowth from explants by serum (20%) over a 20-day period was more pronounced in SV (37+/-5%) than in IMA (4+/-3%; P<.001) of the same patients. Serum (10%) increased cell number more rapidly in SV (2 x 10(4)/well to 18+/-4 x 10(4)/well; P<.05) than in IMA (2 x 10(4)/well to 9+/-4 x 10(4)/well; P<.05) over an 8-day period. PDGF-BB (0.01 to 10 ng/mL) stimulated 3H-thymidine incorporation (1347+/-470% above control levels) and increased cell number in SV (2 x 10(4)/well to 5+/-1 x 10(4)/well; P<.05) but not in IMA. PDGF alpha- and beta-receptors were similarly expressed and were activated in both SV and IMA. PDGF-BB induced a similar MAPK activation (kinetics and maximal activity) in both SV and IMA cells but increased MAPK protein level only in SV. Furthermore, PDGF-BB markedly downregulated the cell cycle inhibitor p27Kip1 in SV, but this was much less pronounced in IMA. CONCLUSIONS: SMCs from SVs exhibit enhanced proliferation compared with IMA in spite of functional growth factor receptor expression and MAPK activation. However, PDGF increased MAPK protein level only in SV and downregulated cell cycle inhibitor (p27Kip1) more potently in SV than in IMA. This may explain the resistance to growth stimuli of IMA SMCs and may contribute to the longer patency of arterial versus venous grafts.

Homograft failure in mycotic aortic aneurysm caused by Streptococcus pneumoniae.

Treatment of a rare Streptococcus pneumoniae mycotic aneurysm by homograft replacement failed in a 59-year-old patient because of persistent lobar pneumonia. Despite reoperation with replacement of the infected homograft by a fresh one, he finally died of septicemia. This case illustrates that homograft tissue may be infected per continuum and that extensive debridement of periaortic tissue-including major lung resection-and the use of muscle flaps may be necessary in certain circumstances.