Contradictory Shear Stress Distribution Prevents Restenosis after Provisional Stenting for Bifurcation Lesions

Background: Endothelial shear stress is one of the local hemodynamic factors suspected in the development of coronary atherosclerosis in bifurcation lesions. In patients with provisional stenting, the endothelial shear stress (SS) distribution is unknown. Objective: The aim of this study was to investigate the magnitude and distribution of the SS of coronary bifurcation lesions stenting by the provisional approach. Methods: Ten consecutive patients were included in this study. Quantitative coronary analysis, flow study, and three‐dimensional computational analysis with the aid of the commercial software CD STAR‐CCM+ were done before and after the provisional stenting procedure and also 8 months later. Results: Clinical and angiographic follow‐up were available in all patients. No patient had a side branch (SB) stent. At the 8‐month follow‐up, no major adverse cardiac event (MACE) occurred. There was also no clinical and angiographic restenosis. Before PCI, the distal main vessel (MV)‐lateral, and the SB‐lateral subsegments had relative nonsignificant lower SS value (4.08 ± 2.78 Pa and 4.35 ± 5.04 Pa, respectively) when compared to other segments. After 8‐month follow‐up, sustained decreased SS value was shown in the distal MV‐lateral segment (4.08 ± 2.78–1.68 ± 1.65 Pa), when compared with significantly increased SS value in the SB‐lateral subsegment 4.35 ± 5.04–16.50 ± 40.45 Pa). The explanation is that after stenting in the MV, the flow was redistributed immediately after percutaneous coronary intervention (PCI) and reversed back to its original 8 months later. However, the growth of the fibrous tissue causing in‐stent restenosis (ISR) is prohibited by sirolimus on the stent struts. In contrast, in a branch opened up by plain old balloon angioplasty (POBA), the flow did not change much, the flow could even be worse because it is shifted to the MV after the cross‐sectional area of the MV improved by stenting. However, thanks to POBA, there is increased fibrous tissue formation, enough to increase the SS and prevent further accumulation of cell and cholesterol needed for more restenosis. Conclusion: In the provisional approach, low endothelial SS correlated with no restenosis for patients who underwent stenting of the MV, while a contradictory combination of high SS and no restenosis was seen in the SB after only POBA. The mechanism of prevention of restenosis in the SB is by increasing the SS while in the MV, the mechanism of prevention of ISR is secondary to sirolimus on the stents struts. (J Interven Cardiol 2010;23:319–329)     

INCREASED EXPRESSION OF IL-15 IN THE SYNOVIUM OF PATIENTS WITH RHEUMATOID ARTHRITIS COMPARED WITH PATIENTS WITH YERSINIA-INDUCED ARTHRITIS AND OSTEOARTHRITIS

Recently, a new player in the cytokine network has been described that is produced by monocytes and can be detected in the rheumatoid synovium: interleukin-15 (IL-15). Since this cytokine may play a role in the accumulation and activation of T-cells, B-cells, and natural killer (NK) cells characteristic of synovial tissue (ST) from patients with rheumatoid arthritis (RA), the expression of IL-15 was studied in ST from RA patients in comparison with ST from patients with reactive arthritis (ReA) and osteoarthritis (OA) and the phenotype of IL-15-positive cells was determined. IL-15 expression was investigated by immunohistochemical analysis of ST from ten patients with RA, ten patients with Yersinia enterocolitica-induced ReA, and nine patients with OA. The immunohistological findings were quantified and the results obtained in the different patient groups were compared. To determine the phenotype of IL-15-expressing cells, double-labelling immunofluorescence was performed. The expression of IL-15 was significantly higher in ST from patients with RA than in ST from patients with ReA or OA. In double-label experiments, co-expression was observed with markers for macrophages, T-cells, and NK cells. The composition of the cellular infiltrate in the synovium of patients with RA might be partly explained by the specific increase in expression of IL-15 in rheumatoid ST. It can be speculated that IL-15 production by inflammatory cells other than macrophages may occur in the rheumatoid synovium. © 1997 by John Wiley & Sons, Ltd.     

Estimation of Severity of Mitral Regurgitation by Digital Image Processing of Doppler Spectral Recordings

In order to test the hypothesis that the intensity of the regurgitant signal (RS) is indicative of severity of mitral regurgitation (MR), we digitized five well-defined MR envelopes in 19 patients and calculated the mean pixel intensity (MPI) of the MR envelope and that of the diastolic inflow signal (DIF) using an offline computer system. The mean age of the patients was 49 years (range 19–78 years). The intensity of the RS was expressed as a ratio of the MPI of DIF (RSI DIF). This ratio was compared to the severity of MR determined by left ventricular angiography (LV angio). The ratio of the RSI DIF correlated well with the angiographic severity of MR (r = 0.9). A ratio of < 0.6 identified patients with moderate to severe MR and a ratio of < 0.6 correlated with mild MR (grade I and II) by LV angio. Our data indicate that MR severity assessed by measurement of the intensity of the RS correlates well with the angiographic determination of MR.     

Prediction of Clinical Outcomes in Patients with Unprotected Left Main Trifurcation Lesions Treated by Drug‐Eluting Stents: Importance of 2‐Stent Technique and SYNTAX Score

Background: There were insufficient data on the prognosis of stenting for patients with trifurcated unprotected left main lesions (UPLMS). Methods: From the SPEED (stents for percutaneous treatment of coronary artery disease) registry of all percutaneous coronary interventions (PCI) for all types of UPLMS, data of 44 patients with trifurcated UPLMS were selected and analyzed. Results: Patients were divided into one‐stent (N = 23) or 2‐stent (N = 21) groups. Clinical follow‐up was available for 100%, and angiographic follow‐up at 8 month was available for 91.3%. There were no differences in myocardial infarction, cardiac death, and stent thrombosis between groups. However, the target lesion revascularization (TLR) and target vessel revascularization (TVR) in the 1‐stent group was lower when compared to the 2‐stent group (13.0% vs. 23.8%, P = 0.004; 13.0% vs. 28.6%, P = 0.003, respectively). Cumulative survival free from major adverse cardiovascular events (MACE) in the 1‐stent group was higher than the 2‐stent group (65.2% vs. 57.1%, P = 0.033). Analysis of the receiver operator curve (ROC) of the Synergy between PCI with Taxus and Cardiac Surgery (SYNTAX) score showed the area under the curve was 0.414 (standard error = 0.089, 95% CI 0.240–0.589, P = 0.348). Conclusions: In patients with trifurcated UPLMS, higher TLR/TVR and lower cumulative survival from MACE were seen in the 2‐stent group when compared to the 1‐stent group. The SYNTAX scoring system had no predictive value of outcomes for patients with stenting of trifurcated UPLMS. (J Interven Cardiol 2010;23:352–357)     

Proliferation signal inhibitors in the treatment of lupus nephritis: Preliminary experience

Aim: Proliferation signal inhibitors (PSI) have demonstrated efficacy in prevention and treatment in an animal model of lupus nephritis (LN) but there are no data regarding the use of PSI in human LN. We report here our experience of using PSI treatment in seven patients with severe proliferative lupus nephritis. Methods: This is a retrospective study on patients with proliferative lupus nephritis who had received PSI treatment. Results: Seven patients were included. Two patients had concomitant membranous lupus nephropathy. The indications for PSI included mycophenolate mofetil intolerance (n = 4), history of malignancy (n = 2) and leucopoenia (n = 1). Five patients were given PSI when disease was active. Two had treatment discontinued because of acute cholecystitis and leucopoenia, respectively. In the other three patients combined steroid and PSI treatment as induction therapy led to improvements in serology, renal function and proteinuria. In two patients treated with PSI and low‐dose steroid as maintenance immunosuppression, both maintained stable lupus serology, renal function and proteinuria over 18 months. Side‐effects included dyslipidemia and oral ulcers. Conclusion: Proliferation signal inhibitors warrants further investigation as an alternative immunosuppressive treatment in lupus nephritis.     

RETROPERITONEOSCOPIC SURGERY IS NOT ASSOCIATED WITH INCREASED CARBON DIOXIDE ABSORPTION

PURPOSE: Previous studies have suggested that retroperitoneal laparoscopy is associated with greater carbon dioxide absorption and related postoperative morbidity, such as subcutaneous emphysema and pneumothorax. We prospectively compared the effects of carbon dioxide absorption during transperitoneal and retroperitoneal laparoscopic renal and adrenal surgery at our institution. MATERIALS AND METHODS: Data were collected prospectively on 51 patients who underwent laparoscopic renal (26) or adrenal (25) surgery via the transperitoneal (18) or retroperitoneal (33) approach from September 1997 to February 1998. RESULTS: There was no significant difference in carbon dioxide elimination in patients who underwent transperitoneal laparoscopy compared to retroperitoneoscopy at any interval. Subcutaneous emphysema occurred in 12.5% of the transperitoneal and 45% of the retroperitoneal group (p = 0.09). Patients with subcutaneous emphysema had greater carbon dioxide elimination during the first 2.5 hours of insufflation compared to those without subcutaneous emphysema and, thereafter, carbon dioxide elimination decreased to baseline. CONCLUSIONS: In contrast to previous reports our prospective nonrandomized study suggests that retroperitoneoscopy is not associated with greater carbon dioxide absorption compared to transperitoneal laparoscopy. Patients with subcutaneous emphysema exhibited only transient increases in carbon dioxide absorption above control levels.     

LAPAROSCOPIC INTRACORPOREALLY CONSTRUCTED ILEAL CONDUIT AFTER PORCINE CYSTOPROSTATECTOMY

PURPOSE: We present our technique of laparoscopic ileal conduit creation after cystoprostatectomy in a porcine model performed in a completely intracorporeal manner. METHODS AND METHODS: After developing the technique in 5 acute animals laparoscopic cystoprostatectomy with intracorporeally performed ileal conduit urinary diversion was performed in 10 surviving male pigs. A 5-port transperitoneal technique was used. All steps of the technique applied during open surgery were duplicated intracorporeally. Specifically cystectomy, isolation of an ileal conduit, restoration of bowel continuity and mucosa-to-mucosa stented bilateral ileoureteral anastomosis formation were performed by exclusively intracorporeal laparoscopic techniques. RESULTS: Surgery was successful in all 10 study animals without intraoperative or immediate postoperative complications. Blood loss was minimal and average operative time was 200 minutes. Stenosis of the end ileal stoma specifically at the skin level was noted in 6 animals. Three deaths occurred 2 to 3 weeks postoperatively. At sacrifice renal function was normal in all surviving animals. No ileo-ureteral anastomotic strictures were noted on pre-sacrifice radiography of the loop or at autopsy examination of the anastomotic sites. CONCLUSIONS: Laparoscopic ileal conduit urinary diversion after cystoprostatectomy may be performed completely intracorporeally in the porcine model. Clinical application of this technique is imminent.