Midterm follow-up of the status of Gore-Tex graft after extracardiac conduit Fontan procedure

Objective: Extracardiac conduit Fontan procedure has some theoretical advantages over other types of Fontan procedures, such as optimized flow dynamics, a lower frequency of arrhythmias, and technical ease of procedure. However, lack of growth potential and thrombogenicity of the artificial conduit is the main concern and can possibly lead to reoperation for the conduit stenosis. In this study, we investigated the change and the status of the Gore-Tex graft used in extracardiac conduit Fontan procedure. Methods: Between 1996 and 2005, 154 patients underwent extracardiac conduit Fontan procedure using Gore-Tex graft. Among these, 46 patients underwent cardiac catheterization during follow-up period. We measured the internal diameter of the conduit and inferior vena cava angiographically. Results: Mean follow-up duration was 36.1 ± 19.7 months. The conduit diameter used was 16 mm in 10 patients, 18 mm in 16, 20 mm in 14, 22 mm in 4, and 24 mm in 2 patients. The mean conduit-to-inferior vena cava cross-sectional area ratio was 1.25 ± 0.33. According to the conduit size used, this ratio was 1.03 ± 0.17 for 16 mm conduits, 1.33 ± 0.37 for 18 mm, 1.33 ± 0.36 for 20 mm, 1.28 ± 0.26 for 22 mm, and 1.05 ± 0.06 for 24 mm conduits (p < 0.05, 16 mm vs 18 mm and 20 mm). The mean percent decrease of the conduit cross-sectional area was 14.3 ± 8.5%, and this did not differ significantly according to the conduit size (p = 0.82). Follow-up duration and the percent decrease of the conduit cross-sectional area did not show significant correlation (r = 0.22, p = 0.14). There was no reoperation due to conduit stenosis. Conclusions: During midterm follow-up of about 3 years, the conduit cross-sectional area decreased by 14%, and this did not differ according to the conduit size used. The extent of decrease of the conduit cross-sectional area remained stable irrespective of the follow-up duration. Sixteen millimeters conduit showed no evidence of clinically significant stenosis, but careful follow-up is warranted because of the possible conduit stenosis relative to the patients’ somatic growth.     

Fate of pulmonary arteries following Norwood Procedure

Objective: This study evaluated the requirement for surgical reoperation and catheter-based reintervention to central pulmonary arteries (CPAs) following Norwood Procedure (NP). We sought to identify the influence of various surgical techniques employed during NP on subsequent interventions. Methods: Between 1993 and 2004, 226 patients underwent Stage II following NP. Ninety-eight patients (43%) had completion of Fontan circulation (Stage III) and a further 107 (47%) are on course for Fontan completion with 21 (9%) inter-stage deaths. During NP, the aortic arch was reconstructed without additional material (n = 91, 40%) or with a pulmonary homograft patch (n = 135, 60%). Pulmonary blood flow was supplied by modified Blalock–Taussig shunt (n = 177, 78%) or right ventricle to pulmonary artery conduit (RV-PA; n = 49, 22%). The CPAs defect was closed directly (n = 69, 31%) or with a patch (n = 157, 69%). Complete resection of coarctation was performed in 126 patients (56%). Results: Ninety-seven patients (43%) required surgical reoperation to CPAs during Stage II. Actuarial freedom from reoperation was 60 ± 3%, 52 ± 4% and 50 ± 4% at 1, 5 and 10 years, respectively. On multivariable analysis, NP with RV-PA increased risk of reoperation (LR 8.3, 5.3–13.2; p < 0.001). Forty-one patients (18%) required catheter-based reintervention on CPAs. Actuarial freedom from reintervention was 98 ± 1%, 72 ± 4% and 58 ± 6% at 1, 5 and 10 years, respectively. CPA problems were almost exclusively limited to the proximal Left pulmonary artery. On multivariable analysis, catheter-based reintervention became more common with time. Complete resection of coarctation increased risk of reintervention (LR 3.9, 1.6–9.6; p < 0.005). Arch reconstruction and CPAs repair techniques did not affect risk of reoperation or reintervention on CPAs. Conclusions: CPA stenoses and hypoplasia need surgical attention in approximately half of all patients undergoing the NP. The need for reoperation is increased when using the RV-PA conduit technique (although the majority of these are performed as part of the Stage II procedure). Catheter reinterventions are almost exclusively confined to the left CPA and are increased when the arch is shortened by resection of the coarctation tissue at time of NP.     

Long-term experiences on cardiac retransplantation in adults

Background: It remains disputed whether cardiac retransplantation should be performed. This study aimed to evaluate our long-term experiences on cardiac retransplantation in adults. Patients and methods: Between March 1989 and December 2004, 2% (28/1290) of cardiac retransplantations were performed. Results: The reasons for cardiac retransplantation were cardiac allograft vasculopathy (n = 13; 47%), primary graft failure (n = 11; 39%), and refractory acute rejection (n = 4; 14%). The 30-day mortality risk was 29% (acute rejection: 50%; primary graft failure: 36%; cardiac allograft vasculopathy: 15%, p = 0.324), compared to 8.5% for primary cardiac transplantation (p < 0.001). The causes of early death were acute rejection (n = 3; 37%), multiorgan failure (n = 3; 37%), primary graft failure (n = 1; 13%), and right ventricular failure (n = 1; 13%). The late mortality rate was 96/1000 patient-years. The causes of late death were acute rejection (n = 4; 50%), cardiac allograft vasculopathy (n = 2; 25%), multiorgan failure (n = 1; 13%), and infection (n = 1; 13%). The 1-, 5-, 10-, and 15-year survival was respectively 78, 68, 54, and 38% (primary cardiac transplantation), and 46, 41, 32, and 32% (cardiac retransplantation) (p = 0.003). The short-term survival for cardiac retransplantation due to cardiac allograft vasculopathy was likely better than primary graft failure and refractory acute rejection (p = 0.09). Conclusion: The overall outcomes of cardiac retransplantation are significantly inferior to primary cardiac transplantation. Cardiac retransplantation should be only performed for selected patients.     

Prognostic value of FDG uptake in early stage non-small cell lung cancer

Background: Non-small cell lung cancer (NSCLC) has a poor prognosis even for early stages of the disease (stage I and II). We studied the prognostic value of PET FDG in patients with completely resected stage I and II NSCLC. Methods: Retrospective study of 96 patients with NSCLC whose staging included ¹⁸F-FDG PET (fluoro deoxy glucose positron emission tomography). Histopathological stage was either stage I (75) or stage II (n = 21). FDG uptake was measured as maximal standardized uptake value for body weight (SUVmax). Mean follow-up was 45 ± 30 months (1–142 months). Overall and cancer-free survival rates were recorded. Results: SUVmax were higher for stage II than for stage I (10.5 ± 4.5 vs 8.5 ± 5, p = 0.04). Mean tumor volumes were equivalent for both stages (33 cm³, p = 0.18), excluding a partial volume effect. The median SUVmax in the whole study population was 7.8. The median survival was significantly longer in patients with a lower (SUVmax ≤ 7.8) FDG uptake (127 months vs 69 months, p = 0.001). For stage I tumors (n = 75), high FDG uptake was significantly associated with reduced median survival: 127 months if SUVmax ≤ 7.8 and 69 months if SUVmax > 7.8 (p = 0.001). For stage II tumors (n = 21), no statistical difference was observed: 72 months vs 40 months for SUVmax ≤ 7.8 and for SUVmax > 7.8, respectively (p = 0.11), although there was a clear trend towards reduced survival for highly metabolic tumors. Disease-free survival was also significantly better for lower metabolic tumors: 96.1 months vs 87.7 months (p = 0.01). Conclusion: High FDG uptake is associated with reduced overall survival and disease-free survival of patients with completely resected stage I–II NSCLC. Whether patients with highly metabolic tumors should undergo a closer postoperative surveillance or adjuvant chemotherapy has to be addressed in a properly designed prospective trial.     

The effects of therapeutic sulfide on myocardial apoptosis in response to ischemia–reperfusion injury

Objective: Ischemia–reperfusion (I/R) injury, often encountered clinically, results in myocardial apoptosis and necrosis. Hydrogen sulfide (H₂S) is produced endogenously in response to ischemia and thought to be cardioprotective, although its mechanism of action is not fully known. This study investigates cardioprotection provided by exogenous H₂S, generated as sodium sulfide on apoptosis following myocardial I/R injury. Methods: The mid-LAD coronary artery in Yorkshire swine (n = 12) was occluded for 60 min, followed by reperfusion for 120 min. Controls (n = 6) received placebo, and treatment animals (n = 6) received sulfide 10 min prior to and throughout reperfusion. Hemodynamic, global, and regional functional measurements were obtained. Evans blue/TTC staining identified the area-at-risk (AAR) and infarction. Serum CK-MB, troponin I, and FABP were assayed. Tissue expression of bcl-2, bad, apoptosis-inducing-factor (AIF), total and cleaved caspase-3, and total and cleaved PARP were assessed. PAR and TUNEL staining were performed to assess apoptotic cell counts and poly-ADP ribosylation, respectively. Results: Pre-I/R hemodynamics were similar between groups. Post-I/R, mean arterial pressure (mmHg) was reduced by 30.2 ± 4.3 in controls vs 8.2 ± 6.9 in treatment animals (p = 0.01). +LV dP/dt (mmHg/s) was reduced by 1308 ± 435 in controls vs 403 ± 283 in treatment animals (p = 0.001). Infarct size (% of AAR) in controls was 47.4 ± 6.2% vs 20.1 ± 3.3% in the treated group (p = 0.003). In treated animals, CK-MB and FABP were lower by 47.0% (p = 0.10) and 45.1% (p = 0.01), respectively. AIF, caspase-3, and PARP expression was similar between groups, whereas cleaved caspase-3 and cleaved PARP was lower in treated animals (p = 0.04). PAR staining was significantly reduced in sulfide treated groups (p = 0.04). TUNEL staining demonstrated significantly fewer apoptotic cells in sulfide treated animals (p = 0.02). Conclusions: Sodium sulfide is efficacious in reducing apoptosis in response to I/R injury. Along with its known effects on reducing necrosis, sulfide's effects on apoptosis may partially contribute to providing myocardial protection. Exogenous sulfide may have therapeutic utility in clinical settings in which I/R injury is encountered.     

Risk factors for reoperation after relief of congenital subaortic stenosis

Background: Congenital subaortic stenosis entails a lesion spectrum, ranging from an isolated obstructive membrane, to complex tunnel narrowing of the left outflow associated with other cardiac defects. We review our experience with this anomaly, and analyze risk factors leading to restenosis requiring reoperation. Methods: From 1994 to 2006, 58 children (median age 4.3 years, range 7 days–13.7 years) underwent primary relief of subaortic stenosis. Patients were divided into simple lesions (n = 43) or complex stenosis (n = 15) associated with other major cardiac defects. Age, pre- and postoperative gradient over the left outflow, associated aortic or mitral valve insufficiency, chromosomal anomalies, arteria lusoria, and operative technique (membrane resection (22) vs associated myectomy (34) vs Konno (2)) were analyzed as risk factors for reoperation (Kaplan–Meier, Cox regression). Results: There was no operative mortality. Median follow-up spanned 2.7 years (range 0.1–10), with one late death at 4 months. Reoperation was required for recurrent stenosis in 11 patients (19%) at 2.6 years (range 0.3–7.5) after initial surgery. Risk factors for reoperation included complex subaortic stenosis (p = 0.003), younger age (p = 0.012), postoperative residual gradient (p = 0.019), and the presence of an arteria lusoria (p = 0.014). For simple lesions, no variable achieved significance for stenosis recurrence. Conclusions: Surgical relief of congenital subaortic stenosis, even with complex defects, yields excellent results. Reoperation is not infrequent, and should be anticipated with younger age at operation, complex defects, residual postoperative gradient, and an arteria lusoria. Myectomy concomitant to membrane resection, even in simple lesions, does not provide enhanced freedom from reoperation, and should be tailored to anatomic findings.     

Inhaled iloprost to control residual pulmonary hypertension following pulmonary endarterectomy

Objective: Pulmonary endarterectomy (PEA) is the standard therapy for patients with chronic thromboembolic pulmonary hypertension (CTEPH). In the immediate postoperative period, persistent pulmonary hypertension increases the risk of acute respiratory or right heart failure. In pulmonary arterial hypertension, prostanoid inhalation has been found to improve pulmonary hemodynamics, right ventricular function, gas exchange, and clinical outcome. We report the results of a double-blinded randomized trial with the aerosolized prostacyclin analogue iloprost in patients with residual pulmonary hypertension after PEA. Methods: Twenty-two patients (age, 55 ± 13 years; 8 females; propofol- and sufentanil-based anesthesia; pressure-controlled mechanical ventilation) were randomized to receive either a single dose of 25 μg aerosolized iloprost (iloprost group; n = 11) or normal saline (placebo group; n = 11) immediately after postoperative ICU admission. Primary endpoints were changes in gas exchange, pulmonary and systemic hemodynamics, and clinical outcome. Results: Iloprost significantly enhanced cardiac index (CI) and reduced mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance [PVR (dyn s cm⁻⁵)] in contrast to placebo. Placebo: pre-inhalation 413 ± 195 versus post-inhalation 404 ± 196 at 30 min (p = 0.051), 415 ± 189 at 90 min (p = 0.929). Iloprost: pre-inhalation 503 ± 238 versus post-inhalation 328 ± 215 at 30 min (p = 0.001), 353 ± 156 at 90 min (p = 0.003). Blood oxygenation remained unchanged. Conclusion: In addition to the effect of PEA, iloprost reduces residual postoperative pulmonary hypertension, decreases right ventricular afterload and may facilitate the early postoperative management after PEA.     

Clinical advantages of using mini-bypass systems in terms of blood product use, postoperative bleeding and air entrainment: an in vivo clinical perspective

Objective: In an effort to minimize the effect of extracorporeal circulation (ECC), mini-bypass is gaining clinical acceptance in routine coronary artery bypass grafting (CABG). These small circuits target combine the clinical advantages of reduced prime, 100% bio-coating and suction blood separation. We demonstrate that the use of mini-bypass in routine CABG reduces homologous blood product use and postoperative bleeding. Our goal was to also demonstrate that these small systems are effective in gaseous microemboli (GME) management as compared to a conventional extracorporeal system. Methods: Prospective, randomized study comparing 30 mini-bypass (Dideco ECC.O™) to 30 conventional systems (n = 30, Dideco 903 Avant™). Study included CABG cases only, independent of preoperative coagulative status; clinic ethical committee approval and informed patient consent was obtained before initiating study. Results: There were no statistical differences in terms of patient demographics. Statistically significant differences were seen in transfusion frequency (27% of the study group vs 43% in the control group, p = 0.05), transfused volume (133.3 ± 244.5 ml vs 325 ± 483.1 ml, p < 0.05), fresh frozen plasma (0 unit vs 3 units, p < 0.001), postoperative bleeding (301.8 ± 531.9 ml vs 785.5 ± 1000.4 ml, p < 0.05) and GME activity post-arterial filter (0.14 μl vs 5.32 μl, p < 0.05). Conclusions: The adoption of mini-bypass significantly potentially reduces hemodilution, donor blood usage, postoperative bleeding and exposure to GME in routine CABG patients as compared to the use of conventional extracorporeal circulation circuits.     

Factors affecting early and long-term outcomes after completion pneumonectomy

Objective: To identify factors that affect operative mortality and morbidity and long-term survival after completion pneumonectomy. Methods: We retrospectively reviewed the charts of consecutive patients who underwent completion pneumonectomy at our cardiothoracic surgery department from January 1996 to December 2005. Results: We identified 69 patients, who accounted for 17.8% of all pneumonectomies during the study period; 22 had benign disease and 47 malignant disease (second primary lung cancer, n = 19; local recurrence, n = 17; or metastasis, n = 11). There were 50 males and 19 females with a mean age of 60 years (range, 29–80 years). Postoperative mortality was 12% and postoperative morbidity 41%. Factors associated with postoperative mortality included obesity (p = 0.005), coronary artery disease (p = 0.03), removal of the right lung (p = 0.02), advanced age (p = 0.02), and renal failure (p < 0.0001). Preoperative renal failure was the only significant risk factor for mortality by multivariate analysis (p = 0.036). Bronchopleural fistula developed in seven patients (10%), with risk factors being removal of the right lung (p = 0.04) and mechanical stump closure (p = 0.03). Overall survival was 65% after 3 years and 46% after 5 years. Long-term survival was not affected by the reason for completion pneumonectomy. Conclusion: Although long-term survival was acceptable, postoperative mortality and morbidity rates remained high, confirming the reputation of completion pneumonectomy as a challenging procedure. Significant comorbidities and removal of the right lung were the main risk factors for postoperative mortality. Improved patient selection and better management of preoperative renal failure may improve the postoperative outcomes of this procedure, which offers a chance for prolonged survival.     

Effects of pre-natal and early post-natal undernutrition on adult internal thoracic artery function

Objective: Previous studies in humans and animals have suggested that undernutrition in utero and in early post-natal life may lead to altered vascular function in a number of peripheral arteries. We investigated the effect of pre- and post-natal nutrient restriction on the vascular reactivity of the left internal thoracic artery using a sheep model. Methods: Welsh mountain ewes were mated and assigned to three dietary groups: (1) 100% of total nutritional requirements (control, n = 6); (2) 50% of total nutritional requirements during the first 31 days of gestation (n = 6); and (3) 50% nutritional restriction during the first 31 days of gestation, followed by a restriction in the diet of their offspring 12–25 weeks post-natally, designed to produce a 15% reduction in growth trajectory (n = 7). The male offspring were sacrificed at 130 weeks; the left internal thoracic artery was mounted onto a wire myograph and the reactivity of the vessel to various agonists measured. Results: The offspring of animals who underwent an early gestation nutrient restriction had a significantly increased basal tone (0.41 ± 0.25 vs 6.34 ± 1.35, p = 0.015) and sensitivity to phenylephrine (log EC₅₀: −6.23 ± 0.04 M vs −5.74 ± 0.17 M, p = 0.036) as compared with control animals. However, this phenomenon was not seen in animals that underwent both pre- and post-natal nutrient restriction. Conclusions: Pre-natal undernutrition increases the basal tone and sensitivity of the left internal thoracic artery to phenylephrine. This effect is significantly attenuated by continued undernutrition in early post-natal life. These experiments suggest that in utero and early post-natal undernutrition may be important determinants of graft function in later life.     

Reconstruction of the RVOT with valved biological conduits: 25 years experience with allografts and xenografts

Objective: The reconstruction of the RVOT in congenital heart disease often requires the implantation of a valved conduit. Although allografts are considered the conduit of choice their availability is limited and therefore xenografts are implanted as well. We compared the long-term durability of both grafts in the RVOT over a 25-year period. Methods: Between January 1974 and August 1999, 505 patients (median age 4.0 years, range 2 days–31 years; median weight 14.5 kg, range 2.2–76.6 kg; median body length 103 cm, range 48–183 cm) with congenital malformations (PA 25.3%, TOF 14.5%, TOF+PA 2.4%, DORV 4.2%, TGA+PS 8.7%, TAC 24.8%, and other 20.2%) received their first valved conduit (174 xenografts: median diameter 14 mm, range 8–27 mm; 331 allografts: median diameter 19 mm, range 8–30 mm). Results: Follow-up is 3017 patient-years. The 10-year survival-probability for all patients. was 66% with a mean reoperation-free interval for conduit-exchange of 13.3 years (mean reoperation-free interval for allografts, 16.0 years; mean reoperation-free interval for xenograft, 10.3 years). One hundred and thirteen patients underwent a conduit-exchange, mostly due to conduit stenosis. Fourteen patients had a second exchange and three patients a third exchange. For patients with conduit diameters <18 mm (n=235: allograft n=116, xenograft n=119; median age 9 months, range 0–27.3 years), the mean reoperation-free interval was 11.2 years (mean interval allograft, 13.1 years; mean interval xenograft, 8.6 years, P=0.03). For conduit diameters ≥18 mm (n=270: allograft n=215, xenograft n=55, median age 7.4 years, range 0–34.3 years) the mean interval from freedom of conduit exchange was 15.1 years (for allografts 14.1 years, for xenografts 12.5 years, P<0.01). Comparing xenografts to allografts, we found no difference in patient survival probability (P=0.62). There was no significant difference between antibiotic (n=198) preserved vs. cryopreserved (n=133) allografts (P=0.06). Blood group compatibility of allografts to recipients had no significant influence on allograft function (P=0.42). The donors allograft origin, whether aortic or pulmonary valve, had also no significant influence on allograft long-term function (P=0.15). Conclusion: For the reconstruction of the right ventricular outflow tract (RVOT) allografts show significantly better long-term durability than xenografts regardless of the age at implantation and the diameter.     

Preliminary experience with inhaled milrinone in cardiac surgery

Background: Inhaled administration of milrinone reduces pulmonary artery pressure. Pulmonary hypertension (PH) and right heart failure are associated with difficult separation from cardiopulmonary bypass (CPB). Therefore, inhaled milrinone could facilitate separation from CPB. Objective: To determine the impact and timing of administration of inhaled milrinone. Methods: A retrospective analysis of our experience on high-risk patients receiving inhaled milrinone was conducted to evaluate the postoperative course after administration of the drug. Results: Seventy-three patients received inhaled milrinone from June 2002 to February 2005. Mean age was 64 ± 13 years, with a mean preoperative Parsonnet score of 27 ± 14. Inhaled milrinone (5 mg) was administered before (n = 30) or after (n = 40) CPB, three patients had off-pump procedures and were excluded. CPB time was 145 ± 78 min with cross-clamping times of 91 ± 56 min without any significant difference between groups. Fifty-four patients (74%) had difficult separation from CPB, 14 patients (19%) required an intra-aortic balloon pump and 10 patients (14%) needed emergency reinitiation of CPB for hemodynamic instability. Ten patients died in the perioperative period (13.7%). Patients receiving inhaled milrinone prior to CPB initiation had a lowering pulmonary artery pressure after CPB (p < .01) and had less emergency reinitiation of CPB after weaning (3% vs 23%, p = .02) as compared to those with administration after CPB. No detectable side effects were directly linked to the administration of the drug. Conclusion: In this high-risk cohort, use of inhaled milrinone was well tolerated. Administration before initiation of CPB could help weaning from CPB.     

Does radial use as a second arterial conduit for coronary artery bypass grafting improve long-term outcomes in diabetics?

Objectives: The evidence supporting the survival benefit of multiple arterial grafts in the general coronary bypass surgery (CABG) population is compelling. Alternatively, results of studies comparing 2 versus 1 internal thoracic artery (ITA) grafts in diabetics have reported conflicting survival data. The use of radial versus ITA as the second arterial conduit has not been studied. Methods: We obtained complete death follow-up in 1516 consecutive diabetic [64 ± 10 years (mean ± SD). Insulin/no insulin: There were 540 (36%)/976 (64%)] primary isolated CABG patients all with ≥1 ITA grafts. The series included 626 ITA/radial (41%) and 890 ITA/vein (59%) patients. Using separate radial-use propensity models, we matched one-to-one 475 (76%) ITA/radial to 475 (53%) unique ITA/vein patients; each including 166 insulin and 309 no insulin patients. Results: Unadjusted survival was markedly better for (1) ITA/radial (94.3%, 86.7% and 70.4% at 1, 5 and 10 years, respectively) versus ITA/vein (91.8%, 74.5% and 53.8%; p < 0.0001) and (2) for no insulin (94.2%, 82.8% and 65.5%) versus insulin (90.4%, 73.1% and 49.2%; p < 0.0001). In matched patients, 11-year Kaplan–Meier analysis showed essentially identical ITA/radial and ITA/vein survival for all diabetics combined (p = 0.53; log rank) and for the no insulin (p = 0.76) cohort. Lastly, a trend for better ITA/radial survival in insulin dependent diabetics after the second postoperative year did not reach significance (p = 0.13). Conclusions: Using radial as a second arterial conduit as opposed to vein grafting did not confer a survival benefit in diabetics. This unexpected result is perhaps related to relatively diminished radial graft patency and/or the augmented radial vasoreactivity characteristic of diabetics. These findings indicate that the radial survival advantage demonstrated in the general CABG population lies primarily in non-diabetics in whom this advantage may be underestimated.     

Spinal cord ischemia after elective endovascular stent-graft repair of the thoracic aorta

Background: We reviewed our experience to investigate the determinants of paraplegia/paraparesis after endovascular stent-graft repair of the thoracic aorta, to assess the influence of the artery of Adamkiewicz (ARM) detected by preoperative magnetic resonance angiography (MRA) and to identify patients at risk. Methods: Over a 5-year period (March 2001–June 2006), 149 patients underwent elective endovascular stent-graft repair of the descending thoracic aorta. Patient demographics and perioperative factors relating to the endovascular procedure were evaluated by using univariate statistical analyses. To assess the influence of the ARM in the thoracolumbar region, patients in whom ARM was detected by preoperative MRA were divided into two groups: patients who had occlusion of the intercostal artery for ARM due to stent-graft (group A, n = 33) and patients who had patency of the intercostal artery for ARM following stent-graft (group B, n = 38). Results: Five (3.6%) of the 144 patients had paraparesis/paraplegia. Two of these five patients had previously undergone operation for total arch replacement with elephant trunk and one had surgery for descending aortic repair. Univariate analyses identified only prior aortic surgery as a significant risk factor (p = 0.04). Paraparesis/paraplegia rates were 10% (three patients) in group A and 0% in group B (p = 0.09). Conclusion: Prior thoracic aortic replacement was found to be a significant predictor of spinal cord ischemia, and therefore vigilance is needed regarding occlusion of the intercostal artery for ARM detected prior to stent-graft repair.     

A three decade analysis of factors affecting burn mortality in the elderly

This study's objective was to identify variables that affect the mortality of elderly burn patients and to assess their changes over time. A retrospective review was conducted on all patients 75 or older (n = 201) admitted to a university-based burn center between 1972 and 2000. Variables examined were age, sex, TBSA, ABSI, inhalation injury, timing from burn to operative intervention, the number of surgical procedures, the number of pre-morbid conditions, and mortality. There were 95 fatalities. TBSA strongly correlated with mortality (p < 0.0001). Adjusting for TBSA and inhalation injury, mortality significantly decreased (p = 0.04, odds ratio = 0.58). Mortality significantly increased with inhalation injury (p < 0.01). Fatality risk increased by 400% with inhalation injury. Absence of inhalation injury was not significant with respect to mortality in the 1970s, however there was a significant decrease (p = 0.02) in mortality without an inhalation injury in the 1980s and 1990s. ABSI was strongly predictive of mortality (p < 0.0001). On average there was a 200% increase in mortality per unit increase of ABSI. The elderly are 58% less likely to die from burns now as compared to the 1970s. Although mortality rose with increasing TBSA equally in each decade, the absolute risk of mortality decreased over time. This data suggests major strides have been made in burn care, however similar success has not been achieved with inhalation injuries.     

Retransfusion of pericardial blood does not trigger systemic coagulation during cardiopulmonary bypass

Objective: During cardiopulmonary bypass (CPB), systemic coagulation is believed to become activated by blood contact with the extracorporeal circuit and by retransfusion of pericardial blood. To which extent retransfusion activates systemic coagulation, however, is unknown. We investigated to which extent retransfusion of pericardial blood triggers systemic coagulation during CPB. Methods: Thirteen patients undergoing elective coronary artery bypass grafting surgery were included. Pericardial blood was retransfused into nine patients and retained in four patients. Systemic samples were collected before, during and after CPB, and pericardial samples before retransfusion. Levels of prothrombin fragment F₁₊₂ (ELISA), microparticles (flow cytometry) and non-cell bound (soluble) tissue factor (sTF; ELISA) were determined. Results: Compared to systemic blood, pericardial blood contained elevated levels of F₁₊₂, microparticles and sTF. During CPB, systemic levels of F₁₊₂ increased from 0.28 (0.25–0.37; median, interquartile range) to 1.10 (0.49–1.55) nmol/l (p = 0.001). This observed increase was similar to the estimated (calculated) increase (p = 0.424), and differed significantly between retransfused and non-retransfused patients (1.12 nmol/l vs 0.02 nmol/l, p = 0.001). Also, the observed systemic increases of platelet- and erythrocyte-derived microparticles and sTF were in line with predicted increases (p = 0.868, p = 0.778 and p = 0.205, respectively). Before neutralization of heparin, microparticles and other coagulant phospholipids decreased from 464 μg/ml (287–701) to 163 μg/ml (121–389) in retransfused patients (p = 0.001), indicating rapid clearance after retransfusion. Conclusion: Retransfusion of pericardial blood does not activate systemic coagulation under heparinization. The observed increases in systemic levels of F₁₊₂, microparticles and sTF during CPB are explained by dilution of retransfused pericardial blood.     

Human gastroepiploic artery has greater chymase activity than the internal thoracic artery

Objective: Recent reports have demonstrated that long-term patency of the gastroepiploic artery (GEA) in coronary artery bypass grafting (CABG) is less satisfactory compared with the internal thoracic artery (ITA). However, the reason has not been fully elucidated. Angiotensin II is known to play an important role in the development of intimal hyperplasia, we hypothesized that the GEA is different from the ITA with respect to angiotensin II-forming ability. Accordingly, we measured activities of angiotensin II-forming enzymes, angiotensin-converting enzyme (ACE) and chymase, in human GEA and ITA. Methods: Remnant of the GEAs and ITAs were obtained from 24 patients who underwent CABG in which both conduits were used simultaneously. Activities of ACE and chymase were measured by using the extract form the GEA or ITA. Sections of the GEA or ITA were immunohistochemically stained with anti-human chymase antibody. Results: The ACE activity of the GEA (0.28 ± 0.16 mU/mg protein) was greater than that of the ITA (0.18 ± 0.11, p < 0.001). The chymase activity of the GEA (11.11 ± 7.15 mU/mg protein) was also greater than that in the ITA (7.13 ± 4.89, p < 0.001). The density of chymase-positive cells in the GEA (3.8 ± 4.2 cells/mm²) was greater than that in the ITA (1.1 ± 1.2, p < 0.01). Conclusion: Activities of both ACE and chymase were significantly greater in the GEA compared with the ITA. The GEA may be different from the ITA with respect to potential ability of angiotensin II-formation.     

Quality assessment of distal SAS connector anastomosis by 13 MHz epicardial ultrasound

Objective: During application of a distal coronary bypass connector, we employed 13 MHz epicardial ultrasound to evaluate quantitative caliper measurements for vessel size matching and to assess anastomosis quality after connector deployment. Methods: Two S²AS connector anastomoses were constructed on ex vivo pressure-perfused porcine hearts. Epicardial ultrasound measurements of the connector ring and anastomosis were compared to intravascular ultrasound measurement and cast dimensions. In 21 pigs, anastomotic sites with internal diameter of 2.25–3.0 mm (internal mammary artery, IMA) and 1.8–2.2 mm (left anterior descending coronary artery, LAD) were selected using external caliper and epicardial ultrasound measurements. Anastomoses were visualized and assessed intraoperatively (beating heart, n = 21) and at 3 and 6 months’ follow-up (explanted heart, n = 10 each). Results: Epicardial ultrasound underestimated connector dimension by ≤5% versus intravascular ultrasound and deviated ≤13% from cast dimensions for other anastomotic measurements. Caliper estimates of internal IMA and LAD diameter differed from ultrasound by −3 ± 6% and −2 ± 7% (mean ± SD), respectively. Intraoperatively, the anastomotic orifice was flawless in all animals. It remained fully patent at 3 and 6 months by ultrasound, which was confirmed by histology. The connector to LAD percentage diameter stenosis changed from −12 ± 5% intraoperatively to −1 ± 7% at 3 months and from −5 ± 6% intraoperatively to −16 ± 13% at 6 months, in the growing pig model. Conclusions: In the pig, external caliper measurements provided a reliable quantitative estimate of inner graft and coronary diameter for connector size matching. Epicardial 13 MHz ultrasound is a promising method to assess coronary anastomosis quality even when connector metal is present.     

Genetic background influences fluoride's effects on osteoclastogenesis

Excessive fluoride (F) can lead to abnormal bone biology. Numerous studies have focused on the anabolic action of F yet little is known regarding any action on osteoclastogenesis. Little is known regarding the influence of an individual's genetic background on the responses of bone cells to F. Four-week old C57BL/6J (B6) and C3H/HeJ (C3H) female mice were treated with NaF in the drinking water (0 ppm, 50 ppm and 100 ppm F ion) for 3 weeks. Bone marrow cells were harvested for osteoclastogenesis and hematopoietic colony-forming cell assays. Sera were analyzed for biochemical and bone markers. Femurs, tibiae, and lumbar vertebrae were subjected to microCT analysis. Tibiae and femurs were subjected to histology and biomechanical testing, respectively. The results demonstrated new actions of F on osteoclastogenesis and hematopoietic cell differentiation. Strain-specific responses were observed. The anabolic action of F was favored in B6 mice exhibiting dose-dependent increases in serum ALP activity (p < 0.001); in proximal tibia trabecular and vertebral BMD (tibia at 50&100 ppm, p = 0.001; vertebrae at 50 and 100 ppm, p = 0.023&0.019, respectively); and decrease in intact PTH and sRANKL (p = 0.045 and p < 0.001, respectively). F treatment in B6 mice also resulted in increased numbers of CFU-GEMM colonies (p = 0.025). Strain-specific accumulations in bone [F] were observed. For C3H mice, dose-dependent increases were observed in osteoclast potential (p < 0.001), in situ trabecular osteoclast number (p = 0.007), hematopoietic colony forming units (CFU-GEMM: p < 0.001, CFU-GM: p = 0.006, CFU-M: p < 0.001), and serum markers for osteoclastogenesis (intact PTH: p = 0.004, RANKL: p = 0.022, TRAP5b: p < 0.001). A concordant decrease in serum OPG (p = 0.005) was also observed. Fluoride treatment had no significant effects on bone morphology, BMD, and serum PYD cross-links in C3H suggesting a lack of significant bone resorption. Mechanical properties were also unaltered in C3H. In conclusion, short term F treatment at physiological levels has strain-specific effects in mice. The expected anabolic effects were observed in B6 and novel actions hallmarked by enhanced osteoclastogenesis shifts in hematopoietic cell differentiation in the C3H strain.     

Systematic mediastinal lymphadenectomy does not increase postoperative immune response after major lung resections

Objective: To assess the influence of mediastinal lymphadenectomy on postoperative concentration of interleukin 6 (IL-6) and interleukin 1 receptor antagonist (IL-1ra) in serum, sputum, and pleural fluid, in patients operated upon due to lung cancer and benign pulmonary diseases. Methods: Thirty-three patients undergoing uncomplicated resections, including 23 with lung cancer and 10 with benign diseases, were analyzed. In patients with right lung cancer we performed a systematic lymphadenectomy, while in patients with left lung cancer systematic sampling was performed. Serum IL-6 and IL-1ra concentration was measured before and after surgery, and on postoperative days 1, 3, and 7, as well as in sputum at the end of surgery and in pleural fluid on postoperative day 1, by ELISA test. Results: In 23 patients with cancer, 19.0 ± 11.43 mediastinal lymph nodes were removed (in 11 patients with right lung cancer 27.6 ± 7.6 and in 12 patients with left lung cancer 11.1 ± 8.1). No differences were found in serum and sputum concentration of IL-6 and IL-1ra between patients after right and left thoracotomy due to cancer and between patients with cancer and patients with benign diseases. Patients with cancer had a lower concentration of IL-1ra in pleural fluid (median 16950, range 16050–45470.05 pg/ml) than patients with benign diseases (76665.6 pg/ml (range 53618–89617.9); p = 0.0008). In 23 cancer patients a negative correlation between concentration of cytokines in pleural fluid and a number of mediastinal lymph nodes resected was observed (Spearman correlation coefficient for IL-6: r = −0.44, p = 0.04; for IL-1ra: r = −0.57, p = 0.01). Such correlation was not observed for a number of positive N2 lymph nodes. Conclusions: Systematic lymphadenectomy added to major lung resection does not increase postoperative humoral immune response in uncomplicated cases, as measured by levels of IL-6 and IL-1ra in serum, pleural fluid, and sputum.