Side-branch Obstruction Research Articles

Predictors of Side Branch Obstruction Following Stenting of the Main Vessel in Coronary Bifurcation Lesions

INTRODUCTION: Percutaneous coronary intervention (PCI) of bifurcation lesions is complicated by the presence of side branch blockage, which contributes to a low procedural success rate and an elevated rate of adverse cardiac events. A shift in the position of the carina and plaque buildup have been proposed as possible causes of SB occlusion. 1,2 It is estimated that between 15-20% of PCI procedures are done to address lesions at coronary bifurcations.3-5 Multiple randomized clinical trials have concluded that an interim stenting procedure should be used for routine bifurcation stenting. 6-11 
 AIM AND OBJECTIVE: To assess the predictors of side branch obstruction following stenting of the main vessel in coronary bifurcation lesions.
 MATERIAL AND METHODS: Total 300 patients were enrolled with coronary bifurcation lesions who were undergoing PCI and had at least one major SB. Major SB definition was the same as what had been found in other studies: diameter ?2.0mm. Patients with SB stenting before MV stenting, LMS disease, or in-stent restenosis were excluded. Using quantitative coronary analysis (QCA) software, all of the baseline and procedure characteristics were analyzed. The Student's t-test was used to compare continuous data. A p-value < 0.05 was considered significant.
 RESULTS: Out of 300 patients, side branch blockage was found in 23 (7.6%) of the patients. The patients were distributed into two groups based on whether they had SB occlusion (SBO) or not. Mean age (years) in the study was 50.36+12.54 in SBO group and 50+30.34 in no-side-branch occlusion (NSBO) group. There were 19(82%) male and 4(18%) female patients in SBO group and 215(77%)male and 62(23%) female in NSBO group. Diameter stenosis of side branch before MV stenting (55%+20 vs30+25%), side branch diameter (2.1+0.3 vs2.2+0.2), bifurcation angle (70+20degree vs 45+22 degree, p=<0.01) and lower TIMI flow in side branch were found significant predictors of major side branch occlusion.
 CONCLUSION: The bifurcation angle, diameter stenosis of the SB, side branch diameter before to main vessel stenting, and TIMI flow grade of the SB prior to MV stenting were all predictive of severe SB occlusion following MV stenting. As a result, these criteria should be considered when designing PCI for bifurcation lesions in order to increase procedure success.
 KEYWORDS: Side branch obstruction, stenting, coronary bifurcation lesions.

T and Small Protrusion (TAP) vs Double-Kissing Crush Technique: Insights From In Vitro Models

BackgroundPercutaneous coronary interventions on complex bifurcation lesions may require implantation of two stents to appropriately treat diffuse side-branch (SB) disease. Comparisons among different bifurcation stenting techniques are continuously attempted by various study designs (bench tests, computer simulations, clinical studies). Among different techniques, double kissing crush (DKC) represents the last evolution for “crushing” while T and small Protrusion (TAP) represents the evolution of “T stenting”. Both techniques are actually gaining popularity, but head-to-head comparisons are lacking. Methods and resultsTwo last generation drug-eluting stents (Synergy™, Boston Scientific, MA, USA and Ultimaster™,Terumo Corp., Japan) were implanted in left main bifurcation bench models using TAP (n = 6 sets) and DKC (n = 6 sets) techniques. A peristaltic pump with fresh porcine blood was used to perfuse the blood through the silicone model at a flow rate of 200 ml/min for 4 min. Optical coherence tomography (OCT) was used to assess stent struts geometry and thrombus formation. SB cross sectional area as well as SB obstruction did not significantly differ between the two techniques. Numerical (but not statistically significant) differences were found in terms of malapposed struts (fewer with TAP) and floating struts (fewer with DKC). Thrombus formation after blood perfusion was similar between TAP and DKC technique (1.53 ± 1.12 vs. 1.20 ± 1.01 mm2, p = 0.6). ConclusionThe result of the present in-vitro study shows the absence of significant difference between TAP and DKC in terms of stent struts apposition and acute thrombus formation potential. Despite the completely different technical steps required, both techniques have similar performance according to such articulated pre-clinical evaluation. What is already known about this subject?Due to its limited complexity, T and Protrusion (TAP) technique is considered the to-go technique for bifurcation lesions with good long-term results. Recently, double kissing crush (DKC) technique has been gaining popularity and demonstrated promising results in randomized clinical trials. What does this study add?This in-vitro bench test study provides a unique detailed OCT comparison and local hemodynamic environment analysis of the two techniques. How might this impact on clinical practice?New insights of acute thrombogenicity and computational flow model simulation may guide percutaneous therapeutic strategies of bifurcation lesions.

P968Comparison of re-proximal optimizing technique with kissing balloon technique in provisional stenting during primary percutaneous coronary intervention

Abstract Background Re-proximal optimizing technique (rePOT) (POT, side branch inflation and final POT) is a new provisional coronary bifurcation stenting technique which has better results in bench tests in comparison with kissing balloon inflation (KBI) techique. A clinical study showed that rePOT had beneficial effects in terms of strut malapposition, side branch obstruction and stent geometry. But it has not been compared with KBI technique especially in patients with ST segment elevation myocardial infarction (STEMI) who underwent primary percutaneous coronary intervention (p-PCI). Purpose The aim of our study is to compare the new rePOT technique with a known and widely used provisional stenting technique in a real-world special patient population in terms of clinical and technical aspects Methods 51 patients with STEMI who underwent p-PCI and needed provisional side branch stenting were enrolled in a tertiary center. Patients who needed “two stent strategy” at the beginning of procedure were deferred. Results Results were shown in Table 1. In-hospital death, contrast induced acute kidney injury, side branch dissection, need for side branch stenting and acute stent thrombosis were lower in rePOT group but there was no statistically significance. Table 1 rePOT group (n=23) KBI group (n=28) p value Age 51.6±11.7 51.2±9.4 0.87 Male gender 18 (78.3%) 24 (85.7%) 0.16 Diabetes Mellitus 3 (13%) 6 (21.4%) 0.43 Hypertension 5 (21.7%) 5 (17.9%) 0.73 Ejection fraction 46.8±10.6 44.8±8.4 0.43 Killip class>2 1 (4.3%) 4 (14.3%) 0.47 Stent type (DES) 21 (91.3%) 23 (82.1%) 0.34 Side branch dissection 3 (13%) 8 (28.6) 0.18 Side branch stenting 3 (13%) 6 (21.4%) 0.43 In-hospital death 2 (8.7%) 3 (10.7%) 0.81 CI-AKI 3 (13%) 6 (21.4%) 0.43 Acute stent thrombosis 0 2 (7.1%) 0.19 DES: Drug eluting stent; CI-AKI: contrast induced acute kidney injury. Conclusion To the best of our knowledge this is the first study which compares the new rePOT technique with KBI in patients with STEMI who underwent p-PCI and needed provisional coronary bifurcation stenting. Although results are similiar in terms of clinical and technical aspects, rePOT may be a useful and user-friendly technique in such a complex and emergent procedure. Acknowledgement/Funding None

Sequential coronary bifurcation revascularization with the Xposition S™ self-apposing stent: a comparative fractal bench study

Coronary bifurcation revascularization needs to take account of the diameter differential between vessels and to limit side-branch obstruction (SBO). The self-apposing properties of the Xposition S™ stent (STENTYS, France) seem interesting in this regard. The present experimental fractal bench study determined the best provisional stenting technique using Xposition S™. Three sequential strategies were compared (n = 5/group): implantation alone, side-branch inflation (SBI), and re-POT (initial proximal optimization technique (POT) + SBI + final POT). 2D- and 3D-OCT analyses and micro-CT scan were performed to quantify the main mechanical results at each step. Of the three groups, SBI and re-POT provided better final results than implantation alone in terms of residual SBO (respectively, 24.6 ± 5.6% and 24.8 ± 5.0% vs. 46.5 ± 10.3%, p < 0.05) and malapposition (respectively, 0.9 ± 0.6% and 0.8 ± 0.4% vs. 3.8 ± 1.9%, p < 0.05). Unlike SBI, the two POTs of the re-POT sequence did not improve the final result. SBI, alone or as part of re-POT, systematically led to one connector breakage, whereas implantation alone maintained complete stent integrity (p < 0.05). In Xposition S™ implantation, SBI should be systematic, but not post-dilatation specifically dedicated to bifurcation stenting (i.e., POTs). However, global post-dilatation is still mandatory to prevent stent underexpansion due to untreated stenosis.

Optimal balloon positioning for the proximal optimization technique? An experimental bench study

AimsThe proximal optimization technique (POT) in coronary bifurcation stenting improves apposition and side-branch obstruction. The POT balloon should be positioned with the distal radio-opaque marker at the carina cut plane. However, the real impact of positioning remains unknown. Methods and resultsSynergy™ stents (Boston Scientific, USA) were implanted on left-main fractal bench models. Initial POT was performed in 3 positions according to distal shoulder position (loss of balloon parallelism) relative to the carina cut plane (n = 5/group): i) “proximal”, 1 mm before carina; ii) “medium”, just at carina; iii) “distal”, 1 mm after carina. Results were quantified on 2D- and 3D-OCT.Compared to implantation, initial POT improved malapposition in all positions (“proximal”: 61.5 ± 1.4% vs. 5.1 ± 2.7%; “medium”: 60.2 ± 2.4% vs. 1.3 ± 0.6%; “distal”: 60.5 ± 2.9% vs. 1.1 ± 1.8%, p < 0.05). However, residual malapposition was greater in “proximal” position (p < 0.05). “Proximal”, unlike “medium” or “distal” POT, also failed to improve side-branch obstruction. Conversely, “distal” POT significantly overstretched the main-branch ostium, with stent/artery ratio 1.22 ± 0.04 vs. 1.11 ± 0.07 for “medium” POT (p < 0.05). ConclusionShoulder positioning is essential to optimize the mechanical benefit of POT without main-branch overstretch (too distal position). Experimentally, the best position is just at the carina cut plane (“medium”).

Safety, efficacy, and removability of a fully covered multi-hole metal stent in a swine model of hilar biliary stricture: a feasibility study.

Background and study aims Use of fully covered self-expandable metal stents (FCSEMS) for biliary drainage of malignant hilar biliary strictures is limited because of risk of cholangitis due to side branch obstruction. The aim of this study was to evaluate the safety and efficacy of unilateral placement of a multi-hole FCSEMS (FCSEMS-MH), which had a 2.5-mm hole in the center of the membrane on each cavity, in a swine model of hilar biliary stricture. Materials and methods Six female mini pigs were included in this prospective study. The hilar biliary stricture model was prepared using an endobiliary radiofrequency ablation. FCSEMS-MHs were endoscopically inserted into the peri-hilar bile duct of all the animals. Outcomes were assessed in terms of adverse events (AEs) including cholangitis, stent patency, stent migration, and endoscopic stent removability for 1 month after stenting. Results In terms of hilar biliary stricture types, two animals were of Bismuth type I and four were of type II. Technical success rate for endoscopic metal stenting was 100 % (6/6), and the functional success rate, which was evaluated 7 days after stent insertion, was also 100 % (5/5). The immediate overall AE rate was 0 %. There was no procedure-related mortality and stent migration did not occur in any animal during the 4-week stent indwelling period. Stents were removed from all six animals at 4 weeks post-stenting. Conclusion Unilateral placement of FCSEMS-MH might be safe and effect for swine hilar biliary stricture models. However, long-term follow-up and comparative studies are needed to verify the usefulness of this stent.

EUS-specific stents: Available designs and probable lacunae.

Interventional EUS has seen exponential growth in its indications and applications in the last decade.[1,2,3] Dedicated endoscopic devices for EUS-guided interventions are still limited. Up until recently, the tools used have been borrowed from other procedures such as ERCP. In interventional EUS, the linear-array echoendoscope allows a needle to be advanced under EUS-guidance from the upper gastrointestinal lumen to the biliary, pancreatic, or another adjacent intestinal lumen. Real-time puncture can be performed and provide the possibility of EUS-guided transluminal drainage (EUS-TLD). Plastic stents and conventional self-expandable metallic stents (SEMSs) were initially used but present several limitations due to their design.[1,4,5] They lack lumen-to-lumen anchorage and present migratory risks in the absence of stricture to hold them in place. Plastic stents are associated with potential pneumoperitoneum and bile peritonitis, whereas fully-covered SEMS (FCSEMS), despite preventing bile leak, will not maintain secure apposition between two nonadherent organs. Furthermore, their length often exceeds the anatomical requirement of a shorter transluminal anastomosis and predisposes them to obstruction as well as difficult positioning. With the rise in new EUS-guided interventional techniques, new tools, in particular, new stent designs have evolved to facilitate the various applications. A few EUS-specific stents have now become available for EUS-TLD.[4,5] We hereby review the stent designs and discuss lacunae to be addressed to improve the efficacy, safety, and ease of procedures.

Benefits of final proximal optimisation technique (POT) in provisional stenting

Initial proximal optimisation technique (POT) in provisional stenting improves global malapposition, side-branch (SB) obstruction (SBO) and conservation of arterial circularity. The specific mechanical effects of a final POT sequence concluding the main provisional stenting techniques, on the other hand, are unknown. SynergyTM stents were implanted on fractal coronary bifurcation bench models using the main provisional stenting techniques ( n = 5 per group): kissing-balloon inflation (KBI), snuggle, and rePOT (initial POT + SB inflation + final POT). Final results were quantified on 2D and 3D OCT before and after final POT. Whichever the technique, final POT significantly decreased global malapposition (from 7.6 ± 5.3% to 2.2 ± 2.5%, P < 0.05) and proximal elliptic deformation (from 1.15 ± 0.07 to 1.09 ± 0.04, P < 0.05), without impact on SBO (from 11.5 ± 9.6% to 12.9 ± 10.6%, NS). However, final POT failed to completely correct the elliptic deformation induced by balloon juxtaposition during the KBI and snuggle techniques, with final elliptic ratios of 1.11 ± 0.03 and 1.11 ± 0.04 respectively, significantly higher than with the full rePOT sequence: 1.05 ± 0.02 ( P < 0.05) ( Fig. 1 ). Like initial POT, final POT is mandatary whatever the provisional stenting technique used. However, final POT fails to completely correct all proximal elliptic deformation associated with “kissing-like” techniques, in contrast to results with the rePOT sequence.

Optimal balloon positioning to maximize the proximal optimization technique (POT)

Proximal optimizing technique (POT) is largely recommended to improve the global malapposition and the side branch (SB) obstruction (SBO). It is classically recommended to position the POT balloon as obtain the distal radio opaque marker at the carina cut plan. However, the real impact of the balloon position is unknown. SynergyTM stents were implanted on left main fractal coronary bifurcation bench models. Initial POT were performed in 3 positioning ( n = 5 per group) as obtain the loose of the balloon parallelism 1 mm before the carina cut plan (proximal), at the carina (medium) and 1 mm after (distal). Final results were quantified on 2D- and 3D-OCT. Compared to the implantation alone, initial POT improved the malapposition in all position (proximal: 64.5 ± 1.4% vs. 5.1 ± 2.7%, medium: 60.2 ± 2.4% vs. 1.3 ± 0.6%, final: 60.5 ± 2.9% vs. 1.1 ± 1.8%, P < 0.05 for all). However the residual malapposition was higher in proximal position compared to the others ( P < 0.05). Proximal POT failed to improve also the final SBO like medium or distal POT ( P < 0.05). On the contrary, distal POT overstretched the proximal part of the main branch illustrated by a stent artery-ratio at 1.22 ± 0.04 vs. 1.11 ± 0.07 in medium POT ( P < 0.05) ( Table 1 ). More than the position of distal radio opaque marker, it seems that the loose of balloon parallelism positioning is essential to obtain the maximum of POT's benefit. A balloon positioning just at the carina cut plan obtain the optimal mechanical final result.

Sequential techniques of provisional stenting in coronary bifurcation with the Xposition S™ self-apposing nitinol stent. A comparative bench study

Coronary bifurcation revascularization needs to take account of the systematic diameter differential between vessels based on fractal geometry, and to limit side-branch obstruction (SBO). The mechanical properties of the Xposition S™ self-apposing stent seem interesting for provisional stenting of coronary bifurcations. The aim of this experimental fractal bifurcation bench study was to determine the best sequential provisional stenting technique with the Xposition S™ self-apposing nitinol stent (STENTYS, France). A fractal bifurcation bench test compared three Xposition S™ provisional stenting strategies: implantation alone, side-branch inflation (SBI) alone, and complete rePOT [initial proximal optimization technique (POT) + SBI + final POT]. Two dimensional- and 3D-OCT analyses and micro-scanner were performed to quantify the main mechanical results at each step. Of the 3 groups ( n = 5 each), SBI alone and complete rePOT provided better mechanical results than implantation alone for residual SBO (respectively, 24.6 ± 5.6% and 24.8 ± 5.0% vs. 46.5 ± 10.3%, P < 0.05) and for malapposition (respectively, 0.9 ± 0.6% and 0.8 ± 0.4% vs. 3.8 ± 1.9%, P < 0.05). Unlike SBI, the POTs did not improve the final rePOT result. SBI, alone or during rePOT, systematically led to only one connector disconnection, whereas implantation alone maintained stent integrity ( P > 0.05) ( Fig. 1 ). This experimental study justifies systematic SBI in clinical practice during provisional stenting with Xposition STM, but not post-dilatation specifically dedicated to bifurcation stenting (i.e., the two POTs in the rePOT sequence). However, global post-dilatation after implantation is still mandatory with Xposition STM stents, to prevent stent under-expansion due to untreated stenosis.

Benefits of final proximal optimization technique (POT) in provisional stenting

AimsInitial proximal optimization technique (POT) in provisional stenting improves global malapposition, side-branch (SB) obstruction (SBO) and conservation of arterial circularity. The specific mechanical effects of a final POT sequence concluding the main provisional stenting techniques, on the other hand, are unknown. Methods and resultsSynergy™ stents were implanted on fractal coronary bifurcation bench models using the main provisional stenting techniques (n = 5 per group): kissing-balloon inflation (KBI), snuggle, and rePOT (initial POT + SB inflation + final POT). Final results were quantified on 2D and 3D OCT before and after final POT. Whichever the technique, final POT significantly decreased global malapposition (from 7.6 ± 5.3% to 2.2 ± 2.5%, p < 0.05) and proximal elliptic deformation (from 1.15 ± 0.07 to 1.09 ± 0.04, p < 0.05), without impact on SBO (from 11.5 ± 9.6% to 12.9 ± 10.6%, NS). However, final POT failed to completely correct the elliptic deformation induced by balloon juxtaposition during the KBI and snuggle techniques, with final elliptic ratios of 1.11 ± 0.03 and 1.11 ± 0.04 respectively, significantly higher than with the complete rePOT sequence: 1.05 ± 0.02 (p < 0.05). ConclusionsLike initial POT, final POT is recommended whatever the provisional stenting technique used. However, final POT fails to completely correct all proximal elliptic deformation associated with “kissing-like” techniques, in contrast to results with the rePOT sequence.

TCT-219 Benefits of final proximal optimization technique (POT) in provisional stenting. A bench experimental study.

Initial proximal optimization technique (POT) in provisional stenting improves global malapposition, side-branch (SB) obstruction (SBO) and conservation of arterial circularity. The specific mechanical effects of a final POT sequence concluding the main provisional stenting techniques, on the other

TCT-468 Sequential techniques of provisional stenting in coronary bifurcation with the Xposition S™ self-apposing nitinol stent. A comparative bench study.

Coronary bifurcation revascularization needs to take account of the systematic diameter differential between vessels based on fractal geometry, and to limit side-branch obstruction (SBO). The mechanical properties of the Xposition S™ self-apposing stent seem interesting for provisional stenting of

Endoscopic drainage in patients with inoperable hilar cholangiocarcinoma.

Hilar cholangiocarcinoma has an extremely poor prognosis and is usually diagnosed at an advanced stage. Palliative management plays an important role in the treatment of patients with inoperable hilar cholangiocarcinoma. Surgical, percutaneous, and endoscopic biliary drainage are three modalities available to resolve obstructive jaundice. Plastic stents were widely used in the past; however, self-expanding metal stents (SEMS) have become popular recently due to their long patency and reduced risk of side branch obstruction, and SEMS are now the accepted treatment of choice for hilar cholangiocarcinoma. Bilateral drainage provides more normal and physiological biliary flow through the biliary ductal system than that of unilateral drainage. Unilateral drainage was preferred until recently because of its technical simplicity. But, with advancements in technology, bilateral drainage now achieves a high success rate and is the preferred treatment modality in many centers. However, the choice of unilateral or bilateral drainage is still controversial, and more studies are needed. This review focuses on the endoscopic method and discusses stent materials and types of procedures for patients with a hilar cholangiocarcinoma.

Invited Commentary

There is accumulating evidence that coronary artery bypass grafting (CABG) after previous percutaneous coronary intervention (PCI) is associated with higher early mortality and major adverse cardiac event (MACE) rates. Several possible explanations are addressed. Dysfunctional and denuded coronary endothelia after PCI initiate an inflammatory response with accumulation of platelets and neutrophils, resulting in microvascular thrombotic obstruction and distal microembolization. Coronary side branch obstruction resulting from stenting may lead to compromised collateral blood flow and focal infarctions. In addition, late structural changes may affect both the stented area and coronary artery territory distal to the stent, which would be the target area of a subsequent bypass graft anastomosis. The coronary artery distal to the stent may have inadequate runoff, and a bypass graft will have decreased patency. Preoperative use of antiplatelet medication such as clopidogrel may cause excess postoperative bleeding, and perioperative discontinuation of antiplatelet medication may cause in-stent thrombosis and adversely influence the results. The CABG patients with previous PCI may have an increased risk of repeated coronary revascularization during follow-up, because the rate of restenosis remains high even in the era of drug-eluting stents. As a result, impaired long-term outcome and decreased quality of life in the CABG patients with previous PCI also are anticipated. Mannacio and colleagues [1Mannacio V. Di Tommaso L. de Amicis V. et al.Previous percutaneous coronary interventions increase mortality and morbidity after coronary surgery.Ann Thorac Surg. 2012; 93: 1956-1963Abstract Full Text Full Text PDF PubMed Scopus (32) Google Scholar] provide early and late clinical outcomes after CABG in patients with previous PCI, compared with outcomes in CABG patients without previous PCI. History of PCI is identified as a risk factor for hospital mortality and MACEs among patients undergoing CABG. The authors also demonstrate that previous PCI is a risk factor for decreased survival at 5-year follow-up. The authors enrolled a large patient cohort (n = 7,855) and performed propensity-score matching with excellent discriminating power (c-statistic of 0.94). However, further data analysis is needed to draw a conclusion that previous PCI affects midterm outcomes after later CABG. Reevaluation, including late occurrence of cardiac death, nonfatal myocardial infarction, and reintervention-free survival, will strengthen the authors' hypothesis. In addition, operative strategy data, such as use of the left internal thoracic artery and saphenous vein grafts and completeness of revascularization, are lacking. Moreover, their survival curve is questionable. The authors indicate that hospital mortalities, which must be included, are not included in their analysis. Both survival curves of the two groups, however, start below 1.0, indicating that hospital mortalities are included in their survival analysis. Survival differences at 5-year follow-up appear to be due to the high hospital mortality in the PCI group patients, rather than late occurrence of events during follow-up. Despite several limitations in this article, I agree with the authors' conclusion and suggestion that all previous PCIs should be treated as a risk factor for subsequent CABG. Although the authors′ findings are not new, I hope this study will strengthen the current evidence for the harmful effects of previous PCI on our CABG patients. Previous Percutaneous Coronary Interventions Increase Mortality and Morbidity After Coronary SurgeryThe Annals of Thoracic SurgeryVol. 93Issue 6PreviewThis multicenter study investigated the impact of previous percutaneous coronary interventions (PCI) on postoperative outcome and 5-year survival of subsequent coronary artery bypass grafting. Full-Text PDF

A case of coronary lesion with lotus root appearance treated by percutaneous coronary intervention with intravascular ultrasound guidance

A 66-year-old man underwent percutaneous coronary intervention (PCI). Coronary angiography showed a diffuse lesion with lotus root appearance and severe stenosis in the left anterior descending artery (LAD). Multiple channels were observed by intravascular ultrasound (IVUS). Different channels were connected to the first diagonal branch, the first septal branch and LAD lumen separately. To prevent obstruction of side branches, we made connections to the branches from the main channel of LAD with tapered-tip guide wire, followed by balloon dilatation and stenting without side branch obstruction. IVUS findings were helpful for the PCI with a lotus root appearance lesion.

Bioabsorbable Coronary Stents

Percutaneous coronary intervention (PCI) with bioabsorbable stents has created interest because the need for mechanical support for the healing artery is temporary, and beyond the first few months there are potential disadvantages of a permanent metallic prosthesis. Stents improve immediate outcomes, including profoundly reducing acute vessel occlusion after PCI by scaffolding intimal tissue flaps that have separated from deeper layers and by optimizing vessel caliber. They limit restenosis by preventing negative remodeling.1 The intimal hyperplastic healing response to PCI that contributes to restenosis, especially after bare metal stenting, can be limited by coating stents with antiproliferative medications.2,3 Potential advantages of having the stent disappear from the treated site include reduced or abolished late stent thrombosis, improved lesion imaging with computed tomography or magnetic resonance, facilitation of repeat treatments (surgical or percutaneous) to the same site, restoration of vasomotion, and freedom from side-branch obstruction by struts and from strut fracture-induced restenosis. Bioabsorbable stents have a potential pediatric role because they allow vessel growth and do not need eventual surgical removal.2 The progression of stenosis seen within stents 7 to 10 years after stenting has been attributed, at least in part, to inflammation around metallic struts, which might argue for an absorbable stent.3 Progression is also observed late after balloon angioplasty.4 Some patients say they prefer an effective temporary implant rather than a permanent prosthesis. Although the concept of bioabsorbable stents has created interest for >20 years, there are challenges in making a stent that has sufficient radial strength for an appropriate duration, that does not have unduly thick struts, that can be a drug delivery vehicle, and where degradation does not generate an unacceptable inflammatory response.5,6 We will review the different bioabsorbable stents that have been studied clinically and discuss the duration of the need …

Percutaneous coronary intervention for chronic total occlusions: the role of side-branch obstruction

The aim of this study was to review all percutaneous coronary interventions (PCI) performed in our department for chronic total occlusions (CTO) over the last three years, and analyse the success rate and complications. We retrospectively studied all PCls for total occlusions of more than four weeks duration, performed between 2004 and 2006, after excluding multivessel PCI, venous grafts and in-stent restenosis (n=106 cases). The in-hospital complications were recorded; periprocedural myocardial infarction (MI) was defined as elevation of troponin I more than 3 times the upper reference limit. Procedural success was defined as angiographic success and absence of major adverse cardiac events (MACE: death, large MI, emergency bypass). Logistic regression analysis was used to determine predictors of success and complications. The procedural success was 77%, and was mainly associated with duration of occlusion less than three months (OR 4.17, 95% CI 1.23-14.28, p = 0.02), preprocedural TIMI 1 coronary flow (OR 3.29, 95% CI 1.00-10.82, p = 0.05) and absence of ipsilateral collaterals (OR 4.54, 95% CI 1.35-16.67, p = 0.01). Periprocedural MI occurred in 12 cases (12%), while MACE occurred in 3 (3%). The only parameter significantly associated with periprocedural MI was the obstruction of side-branches (with diameter >1 mm) within 5 mm of the CTO (OR 10.00, 95% CI 1.76-56.67, p < 0.01). In our CTO cohort the success rate was 77%, with a low complication rate. Periprocedural MI was mainly due to obstruction of side-branches.

Invasive endoscopy or surgery for pancreatic disorders?

Endoscopic double papillotomy occupied the place of surgical transduodenal double sphincteroplasty for disorders of papilla of Vater or chronic pancreatitis several years ago. Endoscopic cystoenterostomy and cystogastrostomy can also replace surgery in the treatment of pseudocysts and walled-of necrosis even in cases of severe acute pancreatitis with/or without sepsis. In chronic pancreatitis endotherapy may be the treatment of choice at first, although surgical techniques give somewhat better long-term results for pain relief. Extracorporeal shock wave lithotripsy, stone resolution or extraction and multiple pancreatic stents without aggressive balloon dilatation can progressively calibrate dominant stricture of the main pancreatic duct without further damage, ischemia or obstruction of side branches. Relapse-free period becomes longer (also after stents removal) if alcohol consumption and smoking are stopped definitively. Well-controlled, randomised studies are still needed to demonstrate clinical advantage of multiple endoscopic stent placement in comparison to surgery.

Aortic dissection: new frontiers in diagnosis and management: Part I: from etiology to diagnostic strategies.

Cardiovascular disease is the leading cause of death in most Western societies and is increasing steadily in many developing countries. Aortic diseases constitute an emerging share of the burden. New diagnostic imaging modalities, longer life expectancy in general, longer exposure to elevated blood pressure, and the proliferation of modern noninvasive imaging modalities have all contributed to the growing awareness of acute and chronic aortic syndromes. Despite recent progress in recognition of both the epidemiological problem and diagnostic and therapeutic advances, the cardiology community and the medical community in general are far from comfortable in understanding the spectrum of aortic syndromes and defining an optimal pathway to manage aortic diseases.1–13 This comprehensive review is organized in two parts, with a focus on the etiology, natural history, and classification (with vascular staging) of aortic wall disease in Part I and emphasis on therapeutic management and follow-up in Part II. Both parts may help to better integrate the complexities of acute aortic syndromes.