The Safety and Feasibility of Bilateral Radial Approach in Chronic Total Occlusion Percutaneous Coronary Intervention

Global Consensus Recommendations on Improving the Safety of Chronic Total Occlusion Interventions

Safety is of critical importance to chronic total occlusion (CTO) percutaneous coronary intervention (PCI). This global consensus statement provides guidance on how to optimise the safety of CTO) PCI, addressing the following 12 areas: 1. Set-up for safe CTO PCI; 2. Guide catheter--associated vessel injuries; 3. Hydraulic dissection, extraplaque haematoma expansion, and aortic dissections; 4. Haemodynamic collapse during CTO PCI; 5. Side branch occlusion; 6. Perforations; 7. Equipment entrapment; 8. Vascular access considerations; 9. Contrast-induced acute kidney injury; 10. Radiation injury; 11 When to stop; and, 12. Proctorship. This statement complements the global CTO crossing algorithm; by advising how to prevent and deal with complications, this statement aims to facilitate clinical practice, research, and education relating to CTO PCI.

Incidence, mechanisms, treatment, and outcomes of donor vessel injury during percutaneous coronary interventions for chronic total occlusion

BACKGROUND

Donor vessel injury is a potentially life-threatening complication of chronic total occlusion (CTO) percutaneous coronary intervention (PCI).

AIMS

Our goal was to examine the incidence, mechanisms, treatment, and outcomes of patients with donor vessel injury in a large multicenter CTO PCI registry.

METHODS

We analyzed the baseline clinical and angiographic characteristics, and procedural outcomes of 12,349 CTO PCIs performed between 2012 and 2022 at 44 centers.

RESULTS

The incidence of donor vessel injury was 0.35% (n = 43). The baseline clinical characteristics of patients with and without donor vessel injury were similar. Cases complicated by donor vessel injury were more complex with higher Japanese CTO score (2.9 ± 1.1 vs. 2.4 ± 1.3; p = 0.004) and lower procedural success rate (69.8% vs. 85.2%; p = 0.004). The retrograde approach was used more commonly in donor vessel injury cases (68.9% vs. 30.9%; p < 0.001). Most (53.5%) donor vessel injuries were guide catheter-induced, whereas 20.9% were due to donor vessel thrombosis. Of the 43 patients with donor vessel injury, 36 (83.7%) were treated with stenting and seven (16.3%) received a left ventricular assist device. The incidence of major adverse cardiovascular events (MACEs) was significantly higher in cases with donor vessel injury (23.3% vs. 2.0%; p < 0.001). Of the 43 patients with donor vessel injury, five patients (11.6%) experienced acute myocardial infarction and four patients (9.3%) died.

CONCLUSIONS

Donor vessel injury, occurred in 0.35% of CTO PCIs performed by experienced operators, was mainly due to guide catheter-induced dissection or thrombosis and was associated with lower procedural success and higher MACE.

The importance of the "safety coronary guidewire" in the donor vessel during Chronic total occlusion percutaneous coronary intervention

Donor vessel injury is a well-known complication of chronic total occlusion (CTO) percutaneous coronary intervention (PCI). Due to significant amount of myocardium at risk, donor vessel injury may lead to rapid hemodynamic collapse. In this setting, prompt restoration of blood flow into the donor artery is of paramount importance. Advancement of a safety coronary workhorse guidewire in the donor vessel prior to attempting CTO PCI is a simple maneuver that provides access to the donor artery for rapid coronary intervention and restoration of blood flow, in the event of donor vessel injury. We describe two cases of CTO PCI that illustrate the value of the safety coronary guidewire.

Forewarned Is Forearmed: Machine Learning Algorithms for the Prediction of Catheter-Induced Coronary and Aortic Injuries

Catheter-induced dissections (CID) of coronary arteries and/or the aorta are among the most dangerous complications of percutaneous coronary procedures, yet the data on their risk factors are anecdotal. Logistic regression and five more advanced machine learning techniques were applied to determine the most significant predictors of dissection. Model performance comparison and feature importance ranking were evaluated. We identified 124 cases of CID in electronic databases containing 84,223 records of diagnostic and interventional coronary procedures from the years 2000-2022. Based on the f1-score, Extreme Gradient Boosting (XGBoost) was found to have the optimal balance between positive predictive value (precision) and sensitivity (recall). As by the XGBoost, the strongest predictors were the use of a guiding catheter (angioplasty), small/stenotic ostium, radial access, hypertension, acute myocardial infarction, prior angioplasty, female gender, chronic renal failure, atypical coronary origin, and chronic obstructive pulmonary disease. Risk prediction can be bolstered with machine learning algorithms and provide valuable clinical decision support. Based on the proposed model, a profile of 'a perfect dissection candidate' can be defined. In patients with 'a clustering' of dissection predictors, a less aggressive catheter and/or modification of the access site should be considered.

The comparison of efficacy and safety between transradial and transfemoral approach for chronic total occlusions intervention: a meta-analysis

This meta-analysis compared the outcomes of transradial access (TRA) and transfemoral access (TFA) in chronic total occlusion (CTO) percutaneous coronary intervention (PCI) in recent decades. We searched multiple databases for articles published between January 1, 2015, and December 31, 2020. Six observational studies with 11,736 patients were analyzed. Data included baseline demographics, Japan-chronic total occlusion (J-CTO) score, sheath size, PCI vessel, retrograde method, procedural time, fluoroscopy time, and contrast volume. The more prevalent target CTO vessel was the left coronary artery in the TRA group and the right coronary artery in the TFA group. Higher J-CTO score, longer procedural time, and more contrast volume were seen in the TFA group. In comparison, the TRA group had better procedural success rate (odds ratio (OR), 0.846; 95% confidence interval (CI) 0.749-0.956) and less vascular complications (OR, 0.323; 95% CI 0.203-0.515), but similar retrograde success rate (OR, 0.965; 95% CI 0.382-2.435). In-hospital death (OR, 0.527; 95% CI 0.187-1.489) and major adverse cardiovascular events (OR, 0.729; 95% CI 0.504-1.054) did not differ between the groups. Overall, fewer vascular complications and higher procedural success rates were noted in the TRA CTO PCI population. However, similar retrograde success rates and clinical outcomes were noted between the groups.

Femoral or Radial Approach in Treatment of Coronary Chronic Total Occlusion: A Randomized Clinical Trial

OBJECTIVES

The aim of this study was to compare transradial access (TRA) with transfemoral access (TFA) for chronic total occlusion (CTO) percutaneous coronary intervention (PCI).

BACKGROUND

TRA reduces the risk for vascular access complications but may make complex PCI, such as CTO PCI, more challenging.

METHODS

FORT CTO (Femoral or Radial Approach in the Treatment of Coronary Chronic Total Occlusion) (NCT03265769) was a prospective, noninferiority, randomized controlled study of TRA vs TFA for CTO PCI. The primary study endpoint was procedural success, defined as technical success without any in-hospital major adverse cardiovascular events. The secondary study endpoint was major access-site complications.

RESULTS

Between 2017 and 2021, 610 of 800 patients referred for CTO PCI at 4 centers were randomized to TRA (n = 305) or TFA (n = 305). Mean J-CTO (Multicenter CTO Registry in Japan) (2.1 ± 0.1 vs 2.2 ± 0.1; P = 0.279), PROGRESS CTO (Prospective Global Registry for the Study of Chronic Total Occlusion Intervention) (1.3 ± 0.9 vs 1.1 ± 1.0; P = 0.058) and PROGRESS CTO complication (2.4 ± 1.8 vs 2.3 ± 1.8; P = 0.561) scores and use of the retrograde approach (11% vs 14%; P = 0.342) were similar in the TRA and TFA groups. TRA was noninferior to TFA for procedural success (84% vs 86%; P = 0.563) but had fewer access-site complications (2.0% vs 5.6%; P = 0.019). There was no difference between TFA and TRA in procedural duration, contrast volume, or radiation dose.

CONCLUSIONS

TRA was noninferior to TFA for CTO PCI but had fewer access-site complications.

Feasibility and Safety of Chronic Total Occlusion Percutaneous Coronary Intervention via Distal Transradial Access

Aims: The current study aims to verify the feasibility and safety of chronic total occlusion (CTO)-percutaneous coronary intervention (PCI) via the distal transradial access (dTRA). Methods: Between April 2017 and December 2019, 298 patients who underwent CTO PCI via dTRA were enrolled in this study. The baseline demographic and procedural characteristics were listed and compared between groups. The incidences of access-site vascular complications and procedural complications and mortality were recorded. Results: The mean J-CTO (Japanese chronic total occlusion) score was 2.6 ± 0.9 points. The mean access time was 4.6 ± 2.9 min, and the mean procedure time was 115.9 ± 55.6 min. Left radial snuffbox access was performed successfully in 286 patients (96.5%), and right radial snuffbox access was performed successfully in 133 patients (97.7%). Bilateral radial snuffbox access was performed in 107 patients (35.9%). 400 dTRA (95.5%) received glidesheath for CTO intervention. Two patients (0.7%) developed severe access-site vascular complications. None of the patients experienced severe radial artery spasm and only 2 patients (0.5%) developed radial artery occlusion during the follow-up period. The overall procedural success rate was 93.5%. The procedural success rate was 96.5% in patients with antegrade approach and 87.7% in patients with retrograde approach. Conclusions: It is both safe and feasible to use dTRA plus Glidesheath for complex CTO intervention. The incidences of procedure-related complications and severe access-site vascular complications, and distal radial artery occlusion were low.

The efficacy and safety of transradial and transfemoral approach in treatment of coronary chronic total occlusion: a systematic review and meta-analysis

BACKGROUND

The clinical efficacy and safety of transradial (TR) percutaneous coronary intervention (PCI) in comparison to transfemoral (TF) for chronic total occlusion (CTO) is not well studied in literature. Objectives: We sought to study the outcome and complications associated with TR compared with TF for CTO interventions.

METHODS

After a systematic literature search was done in PubMed and EMBASE, we performed a meta-analysis of studies comparing TF and TR for CTO PCI. Results: Twelve studies with 19,309 patients were included. Compared to those who has TF access, individuals who were treated via TR approach had statistically significant lower access complication rates [odds ratio (OR): 0.33; 95% confidence interval (CI): 0.22 to 0.49; p < 0.0001]. The procedural success was in the favor of TR method (OR: 1.4; 95% CI: 1.31-1. 51; p < 0.0001). The incidence of major adverse cardiovascular and cerebrovascular events (MACCE) and contrast-induced nephropathy were similar in both groups.

CONCLUSION

When compared with TF access interventions in CTO PCI; the TR approach appears to be associated with far less access-site complications, higher procedural success, and comparable MACCE.

Comparison of the transradial and transfemoral approach in treatment of chronic total occlusions with similar lesion characteristics

Objective:

There is limited data on the efficacy and the safety of the transradial approach (TRA) for percutaneous coronary intervention (PCI) of chronic total occlusion (CTO), particularly in comparison with the transfemoral approach (TFA) in lesions with similar complexity.

Methods:

We included 358 patients, who underwent elective CTO PCI between January 2012 and August 2017 and compared the radial (179 patients) and femoral (179 patients) approaches. The J-CTO score was similar in both groups (TRA, 2.5±1.3 vs. TFA, 2.8±1.4, n.s.). The endpoints analyzed included (i) the composite of all-cause death and nonfatal myocardial infarction (MI) and (ii) the composite safety endpoint of major adverse cardiovascular and cerebrovascular events (MACCEs), including death, MI, coronary perforation, contrast-induced nephropathy (CIN), bleeding at the vascular access site requiring transfusion, cardiac tamponade requiring pericardiocentesis, and periprocedural stroke.

Results:

Patients’ demographics, lesion location, lesion characteristics, and the proportion of antegrade vs. retrograde approach were similar in both groups. The procedural success rate of 96.4% in the radial group and 92.9% in the femoral group was comparable. The total fluoroscopy time (TRA, 42.4±15.7 min vs. TFA, 40.5±15.3 min, n.s.) and contrast medium use (TRA, 532.2±21.7 mL vs. TFA, 528.2±24.6 mL, n.s.) was similar in both groups. There was no in-hospital death or periprocedural MI in both groups. There were three coronary perforations in the TFA group, among them one with tamponade, and one coronary perforation the TRA group. Vascular access site complications (TRA, 0.01% vs. TFA, 0.02%) and CIN (TRA, 0.006% vs. TFA, 0.006%) were rare. One stroke as a result of the procedure was observed in the TFA group. No death was registered.

Conclusion:

The radial approach in CTO PCI was as fast and successful as the femoral approach, even in a complex lesion subset.

Impact of single-plane versus Bi-plane imaging on procedural time, fluorescence time, and contrast medium volume in retrograde chronic total occlusion percutaneous coronary intervention

OBJECTIVE

The aim of the study is to evaluate the impact of single-plane and bi-plane imaging on procedural time, fluorescence time, and contrast medium volume in retrograde chronic total occlusion (CTO) percutaneous coronary intervention (PCI).

METHODS

Between January 2008 and December 2015, a total of 359 patients received scheduled retrograde CTO PCI and were enrolled in the study; 119 patients underwent PCI by single-plane imaging, and another 240 patients underwent PCI by bi-plane imaging.

RESULTS

A 95.0% rate of technical success was noted in the single-plane imaging group, and a 95.8% rate of technical success was noted in the bi-plane imaging group. All patients received the CTO approach via the retrograde method, and the retrograde method success rate was 88.2% in single-plane imaging group, and 81.7% in the bi-plane imaging group. A longer procedural time (153.73 ± 53.15 vs 172.88 ± 61.30 min; P = 0.004), longer fluorescence time (71.40 ± 25.96 vs 80.95 ± 34.70 min; P = 0.008), and more contrast medium volume (342.77 ± 102.25 vs 394.58 ± 156.41 mL; P = 0.001) were noted in the bi-plane imaging group. After propensity score match, a longer procedural time, longer fluorescence time, and more contrast volume was noted in bi-plane group.

CONCLUSION

Bi-plane imaging could not decrease procedural time, fluorescence time, and contrast medium volume in retrograde CTO PCI.

Effects of the Right Carotid Sinus Compression Technique on Blood Pressure and Heart Rate in Medicated Patients with Hypertension

OBJECTIVES

To identify the immediate and middle-term effects of the right carotid sinus compression technique on blood pressure and heart rate in hypertensive patients.

DESIGN

Randomized blinded experimental study.

SETTINGS

Primary health centers of Cáceres (Spain).

SUBJECTS

Sixty-four medicated patients with hypertension were randomly assigned to an intervention group (n = 33) or to a control group (n = 31).

INTERVENTION

In the intervention group a compression of the right carotid sinus was applied for 20 sec. In the control group, a placebo technique of placing hands on the radial styloid processes was performed.

OUTCOME MEASURES

Blood pressure and heart rate were measured in both groups before the intervention (preintervention), immediately after the intervention, 5 min after the intervention, and 60 min after the intervention.

RESULTS

The intervention group significantly decreased systolic and diastolic blood pressure and heart rate immediately after the intervention, with a large clinical effect; systolic blood pressure remained reduced 5 min after the intervention, and heart rate remained reduced 60 min after the intervention. No significant changes were observed in the control group.

CONCLUSIONS

Right carotid sinus compression could be clinically useful for regulating acute hypertension.

Influence about the flow of distal branch after intervention of the right coronary artery chronic total occlusion

OBJECTIVE

Limited data are available for the clinical outcomes after the recanalization of right coronary artery (RCA) chronic total occlusion (CTO). The study aims to assess the clinical outcomes in the antegrade flow of the distal branch after successful RCA CTO percutaneous coronary intervention (PCI).

METHODS

Between January 2002 and December 2012, 538 patients who underwent RCA CTO PCI were enrolled. The clinical outcomes as myocardial infarction (MI), target vessel revascularization, cardiac death, major adverse cardiac events, and all-cause mortality, were compared to the antegrade flow of distal branch after successful RCA CTO PCI.

RESULTS

The CTOs were located in proximal segments (57.6%), mid segments (27.5%) and distal segments (14.9%). The average Syntax score was 18.4±9.6 and 47.8% patients had a Syntax score greater than 27.5. A total of 62.8% patients had final thrombolysis of myocardial infarction (TIMI)-3 flow of distal branch, 16.9% patients had final TIMI-3 flow of only one major branch, 11.3% patients had TIMI-1-2 flow, and 8.9% patients had no antegrade flow. The incidence of periprocedural MI was lower in both side branches were preserved (13.9% vs. 23.0% and 18.8%, p=0.01). The clinical outcomes were similar between the groups with and without good antegrade flow of distal side branch. End stage renal disease (ESRD) and left ventricular ejection fraction (LVEF) <40% predicted three-year cardiac death.

CONCLUSIONS

There is no significant difference of clinical outcomes when distal side branches of RCA are recanalized successfully. ESRD and LVEF <40% were the predictors for three-year cardiac death.

Application of a snare technique in retrograde chronic total occlusion percutaneous coronary intervention - a step by step practical approach and an observational study

Percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) has recently become popular among interventional cardiologists. CTO originating from the ostium has been one of the most difficult CTO lesions to treat with PCI for a number of reasons. Our aim was to illustrate a specific technique during retrograde CTO PCI referred to as the "snare technique."We retrospectively examined the use of "snare technique" among 371 consecutive retrograde CTO PCIs performed at our institution between 2006 and 2015."Snare technique" was used in 10 patients among the 371 retrograde CTO PCIs. The baseline clinical and angiographic characteristics of patients with or without "snare technique" were similar. The "snare technique" group had significantly fewer side branches at occlusion (30.0% vs 71.2%, P = 0.01) and a higher incidence of externalization (90% vs 25.5%, P < 0.001). The contrast volume was significantly lower in the "snare technique" group (285.0 ± 68.5 vs 379.2 ± 144.0, P = 0.04). The incidence of major complications, retrograde success, or final success did not differ between the groups.The "snare technique" is safe and feasible in retrograde CTO PCI, especially in cases of difficult coronary engagement in cases such as ostial occlusion, challenging coronary anatomy, or retrograde guidewire cannot get in antegrade guiding catheter.

Complications encountered in coronary chronic total occlusion intervention: Prevention and bailout

Despite the continuing developments of improved medical devices and increasing operator expertize, coronary chronic total occlusion (CTO) remains as one of the most challenging lesion subsets in interventional cardiology. Percutaneous coronary intervention (PCI) of CTO is a complex procedure carrying the risk of complications that are responsible for significant morbidity and mortality. The complications can be classified as coronary (such as coronary occlusion, perforation, device embolization, or entrapment); cardiac non-coronary (such as periprocedural myocardial infarction); extra cardiac (such as vascular access complications, systemic embolization, contrast-induced nephropathy, and radiation-induced injury). Further, certain complications (such as donor vessel dissection or thrombosis) are unique to CTO-PCI. There are also complications related to specialized techniques, such as dissection/reentry and retrograde crossing techniques. A thorough understanding of the potential complications is critical to mitigate risk during these complex procedures.

Randomized comparative study of left versus right radial approach in the setting of primary percutaneous coronary intervention for ST-elevation myocardial infarction

BACKGROUND

Growing evidence suggests that the left radial approach (LRA) is related to decreased coronary procedure duration and fewer cerebrovascular complications as compared to the right radial approach (RRA) in elective percutaneous coronary intervention (PCI). However, the feasibility of LRA in primary PCI has yet to be studied further. Therefore, the aim of this study was to investigate the efficacy of LRA compared with RRA for primary PCI in ST-elevation myocardial infarction (STEMI) patients.

MATERIALS AND METHODS

A total of 200 consecutive patients with STEMI who received primary PCI were randomized to LRA (number [n]=100) or RRA (n=100). The study endpoint was needle-to-balloon time, defined as the time from local anesthesia infiltration to the first balloon inflation. Radiation dose by measuring cumulative air kerma (CAK) and CAK dose area product, as well as fluoroscopy time and contrast volume were also investigated.

RESULTS

There were no significant differences in the baseline characteristics between the two groups. The coronary procedural success rate was similar between both radial approaches (98% for left versus 94% for right; P=0.28). Compared with RRA, LRA had significantly shorter needle-to-balloon time (16.0±4.8 minutes versus 18.0±6.5 minutes, respectively; P=0.02). Additionally, fluoroscopy time (7.4±3.4 minutes versus 8.8±3.5 minutes, respectively; P=0.01) and CAK dose area product (51.9±30.4 Gy cm(2) versus 65.3±49.1 Gy cm(2), respectively; P=0.04) were significantly lower with LRA than with RRA.

CONCLUSION

Primary PCI can be performed via LRA with earlier blood flow restoration in the infarct-related artery and lower radiation exposure when compared with RRA; therefore, the LRA may become a feasible and attractive alternative to perform primary PCI for STEMI patients.

Retrograde Wiring of Collateral Channels of the Heart in Chronic Total Occlusions

Aim:

To conduct a systematic review and meta-analysis on retrograde wiring in chronic total occlusions (CTOs) with focus on its safety and feasibility.

Methods and Results:

We searched publications from 1990 to December 2013 in PubMed, Ovid, EMBASE, and the Cochrane database inserting a number of terms relating to the collateral circulation of the heart in CTOs. A total of 18 case series (n range17-462) with a total of 2280 CTO revascularization attempts fulfilled criteria for a study of retrograde wiring of collateral channels in CTOs. There were no randomized studies comparing a primary antegrade with a primary retrograde approach. Procedural CTO revascularization rates ranged from 67% to 90.6% with a large proportion having previously failed an “antegrade” approach. The septal perforator collaterals and epicardial channels were used in 73.2% (n = 1670) and 21.7% (n = 495) of cases. Although collateral/coronary perforation was not infrequent (n = 90, 5%), serious acute complications were uncommon; in the combined population 18 cases of cardiac tamponade (0.8%) and 3 deaths (0.1%). Septal perforating wiring (79.3%) was significantly more likely to be successful compared to epicardial coronary artery wiring (72.5%) when chosen by the operator as a route of retrograde access to the CTO body (relative risk 1.11 [95% confidence interval: 1.02-1.20; P = .013]).

Conclusion:

Successful retrograde wiring of collateral channels in selected patients undertaken by “CTO dedicated” operators can significantly enhance the chances of revascularization of complex CTOs with a low risk of acute serious complications. Septal perforator channels are significantly more likely to be successfully retrogradely wired compared to epicardial vessels when either is selected, by reference to their anatomical suitability by the operator, as a route of access.

Transradial percutaneous coronary intervention for chronic total occlusion of coronary artery disease using sheathless standard guiding catheters

Objectives

Our aim was to evaluate the feasibility and safety of routine transradial approach (TRA) percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) lesions using the sheathless technique with standard guiding catheters.

Background

Transradial approach PCI was applied for CTO lesions. A major limitation of TRA CTO PCI is the inability to use large guiding catheters because of the relatively small size of the radial artery. Therefore, the sheathless technique for TRA PCI has been recently developed. However, reports on TRA CTO PCI using the sheathless technique are still lacking.

Methods

Sixty-eight patients with CTO lesions were enrolled for TRA PCI using the sheathless technique with standard guiding catheters. The baseline characteristics, coronary angiographic characteristics and major procedure or access site related complications were compared between procedure success and procedure failure group to determine the predictors of success in sheathless CTO PCI. In-hospital and 30-day clinical outcomes were also evaluated in this study. Routine assessments of radial artery occlusion via Doppler ultrasound and pulse oximeter were recorded during one-year clinical follow-up.

Results

The mean duration of CTO by history was 31.8 ± 42.3 months. The 7 Fr standard guiding catheter was used with the sheathless technique in 91.2%, and bilateral sheathless approach in 42.6% of the study patients. The procedure-related complications included coronary perforation needing covered stent deployment (2.9%), cardiac tamponade (2.9%), collateral perforation needing coil deployment (4.4%), and contrast induced nephropathy (2.9%). Only 2 patients (2.9%) experienced forearm ecchymosis at the radial artery access sites. In-hospital mortality and 30-day all-cause mortality were 2.9%, and 30-day MACEs were 1.5%. The rate of radial artery occlusion during one-year clinical follow-up was only 3.0%.

Conclusions

It is feasible and safe to routinely use the sheathless technique with standard guiding catheters for TRA CTO PCI, with a low incidence of procedure-related complications and long-term radial artery occlusion.

Frequency and outcomes of aortocoronary dissection during percutaneous coronary intervention of chronic total occlusions: a case series and systematic review of the literature

BACKGROUND

Aortocoronary dissection can complicate percutaneous coronary intervention (PCI) of chronic total occlusions (CTOs).

METHODS

We retrospectively examined the frequency and outcomes of aortocoronary dissection among 336 consecutive CTO PCIs performed at our institution between 2005 and 2012 and performed a systematic review of the published literature.

RESULTS

Aortocoronary dissection occurred in six patients (1.8%, 95% confidence intervals 0.7%, 3.8%). All aortocoronary dissections occurred in the right coronary artery (CTO target vessel in five patients and donor vessel in one patient). The baseline clinical characteristics of patients with and without aortocoronary dissection were similar. Compared to patients without, those with aortocoronary dissection were more likely to undergo crossing attempts using the retrograde approach (25% vs. 67%, P = 0.036) and experience a major complication (2.4% vs. 33.3%, P = 0.008). Technical and procedural success rates were similar in both groups. Of the six patients with aortocoronary dissection one underwent emergency coronary bypass graft surgery (CABG), four were treated with ostial stenting, and one was treated conservatively without subsequent adverse clinical outcomes. Systematic literature review provided 107 published cases of aortocoronary dissection during PCI, that occurred mainly in the right coronary artery (74.8%) and were treated with stenting (49.5%), emergency CABG (29%), or conservatively (21.5%).

CONCLUSIONS

Aortocoronary dissection is an infrequent complication of CTO PCI and although it can be treated with stents in most patients, it may infrequently require emergency CABG.

Subintimal dissection/reentry strategies in coronary chronic total occlusion interventions

Subintimal dissection/reentry techniques are increasingly being used for crossing coronary chronic total occlusions both antegradely (using a knucle wire or the Bridgepoint system) or retrogradely (using the controlled antegrade and retrograde tracking and dissection, and reverse controlled antegrade and retrograde tracking and dissection technique). Subintimal dissection/reentry techniques can increase procedural success rates, but their subsequent clinical outcomes are poorly studied, and they appear to be associated with high rates of in-stent restenosis and repeat target lesion revascularization. In the present review, we describe in detail the chronic total occlusions subintimal dissection/reentry techniques, clarify the related terminology and summarize the published studies in this area and the current gaps of knowledge.

Transradial Approach for Chronic Total Occlusion Percutaneous Coronary Intervention

Over the last two decades, the transradial approach has gained an important role in interventional cardiology. A large body of evidence exists supporting the safety and feasibility of the transradial approach in a broad spectrum of patients and settings. In addition, the transradial approach has been applied with good results for chronic total occlusion (CTO) recanalization. This article provides an overview of basic principles and techniques required to perform successful transradial CTO percutaneous coronary intervention.