Tortuous Artery Research Articles

Renal denervation in a patient with a highly tortuous renal artery using a guide extension catheter: a case report

BackgroundCatheter-based renal denervation (RDN) has been introduced to treat resistant hypertension. Although the technology of RDN has been largely improved, denervation of tortuous renal arteries remains challenging.Case presentationThis is a case report of a 49-year-old man with drug resistant hypertension. The patient was selected for RDN after ruling out possible causes of secondary hypertension. Computed tomography angiography showed a highly tortuous left renal artery. An Iberis multielectrode ablation catheter failed to reach the target vessel with a regular guiding catheter. A 5-French extension catheter was introduced into the proximal segment of the main left renal artery to provide extra support force, which enabled successful ablation of the highly tortuous left renal artery. His ambulatory blood pressure was significantly decreased at 1 month follow-up.ConclusionsIt is feasible and effective to use a guide extension catheter for denervation of highly tortuous renal arteries. The present study provides a useful method to ablate tortuous and angled renal arteries and branches.

Upper digestive hemorrhage secondary to major duodenal papilla Dieulafoy’s lesion: Case report

Introduction: Dieulafoy’s lesion (DL) is occasioned by a tortuous, persistent and large caliber artery that emerges the mucosa from the submucosa of an organ, eventually triggering gastrointestinal bleeding in the presence of eroding factors of the mucosa and arterial wall. The presence of DL has been described in many anatomic topographies and although it predominates in the upper digestive tract, the presence of this lesion exactly in the major duodenal papilla is a rare event. Objective: to report a case of upper gastrointestinal bleeding secondary to a major duodenal papilla DL. Case report: a 72 year-old female, admitted to hospital care with a clinical history of two months continuous, painless melena, multiple previous blood transfusions and symptomatic anemia. She was referred by another health service with the diagnostic hypothesis of hemobilia, suggested by two previous esophagogastroduodenoscopies. Her abdominal ultrasound and arteriography were normal. A third esophagogastroduodenoscopy evidenced active bleeding in the duodenal major papilla, and after a carefully analysis a papillar DL was diagnosed. It was treated by endoscopy with adrenaline 1:10000 injection and thermocoagulation. Following this procedure she evolved with severe acute pancreatitis due to papillitis and need of intensive care unit admission. No rebleeding was detected and hospitalar discharge occurred twenty days after hospitalization. Conclusion: The localization of a DL at the major papilla is a rare event and acute pancreatitis is a complication related to its endoscopic treatment.

Moynihan's Lump as an unusual variant of right hepatic artery during a laparoscopic cholecystectomy approach. A case report.

Introduction and importanceOne of the most important measures during the cholecystectomy procedure is based on a “Culture for Safe Cholecystectomy (CSC)”. Vascular injury reports an open surgery conversion rate of 0 to 1.9% and a mortality of less than 0.02%. The caterpillar or Moynihan's hump configuration is characterized by a tortuous right hepatic artery (RHA) running proximal and/or parallel to the cystic duct and predisposes to a small and/or short cystic artery (CA).Case presentationA 65-year-old woman with no relevant clinical history underwent a laparoscopic cholecystectomy (LC) for cholelithiasis; during the procedure a caterpillar or Moynihan's hump was identified.Clinical discussionAnatomical variations represent 20-50% of all cases; therefore, CVS is required. The incidence of caterpillar or Moynihan's hump varies between 1% and 13% of all cases. To date, the scientific literature on this topic is limited. The most accepted etiology is related to embryological formation.ConclusionBiliary and arterial variations are more frequent than we think, so an anatomical knowledge, CSC and CVS represent a fundamental rule, increasing the safety of the surgical procedure.

Airway Management of the Deformed Trachea Using T-Tube Stents in Patients with Mucopolysaccharidosis Type IVA.

Mucopolysaccharidosis (MPS) type IVA usually results in airway obstruction due to thoracic cage deformity and crowding of intrathoracic structures, causing tracheal compression by the tortuous innominate artery. To offer an alternative and effective method in dealing with the challenged deformity of the airway in patients with MPS type IVA. We present 3 patients with MPS type IVA who underwent airway stenting using Montgomery® T-tube stents. Three-dimensional reconstructed computed tomography was essential to design the T-tube and evaluate the anatomical relationship between the innominate artery and the trachea. The Y-shaped Montgomery® Pediatric Safe-T-Tube™ is more suitable for MPS type IVA. Regular follow-ups using fiberoptic bronchoscopy are necessary to evaluate the complications. All 3 patients had good outcomes during the follow-ups until present, despite the complication of granulation formation, which was resolved by revising the limbs of the T-tube. T-tube stents placed below the vocal cord may restore airway patency and preserve laryngeal function, including respiration, phonation, and swallowing, in patients with MPS type IVA.

Feasibility of the Transseptal Approach for Mapping and Ablation in Patients with Ventricular Aneurysm-Related Ventricular Tachycardia with a Steerable Sheath

Background: A retrograde transaortic access might be limited in mapping and ablation for some left ventricular (LV) arrhythmias. We examined the feasibility and safety of a transseptal approach for catheter ablation of LV aneurysm (LVA)-related ischemic ventricular tachycardia (VT). Subjects and Methods: Five consecutive patients with postinfarction LVA-related VT were selected for catheter ablation at Fuwai Hospital from April 2011 to October 2015 in this retrospective study. After a routine transaortic LV-mapping approach was failed, a transseptal approach with a steerable sheath was performed in all these cases. The study was approved by the Ethics Committee of Fuwai Cardiovascular Hospital (approval No. 2016-768) on May 24, 2016. Results: In these five patients, four had LVAs located in the LV apical area, and one in the septum. Acute ablation successes were all failed to achieve through the transaortic route. Two were due to aortic stenosis and tortuous peripheral arteries and the others were due to failure to target the effective sites. While all ablation procedures succeeded through the sequent transseptal approach with a steerable sheath, and no major complications related to the transseptal approach were reported. During the 12-month (10–12 months) follow-up, no electrical storm or episode of VT was documented. One VT recurrence occurred, yet acute success was obtained again through the transseptal approach. Conclusions: Transseptal approach appears a feasible, safe, and effective method in catheter ablation for VT with LVA and could be considered as an elective approach.

Balloon Deflection Technique to Facilitate Stent Delivery in Impassable Situations During Percutaneous Coronary Intervention.

BackgroundLong and multiple lesions especially in the background of tortuous coronary artery often require multiple stents. The entry and passage of another stent through an already deployed stent becomes challenging because of poorly expanded stent struts, calcified tissue, underlying tortuosity, highly angulated takeoff of the vessel, and lack of coaxiality. It can be facilitated by balloon deflection technique (BDT) where balloon at proximal edge of main vessel stent over a buddy wire helps to deflect second stent either distally or into side branch by blocking potential dead.MethodsThe present retrospective, single-center study included 16,189 consecutive patients who underwent percutaneous coronary intervention (PCI) either through transfemoral or transradial route from January 2014 to August December 2019 at LPS Institute of Cardiology, GSVM Medical College, Kanpur, UP, India where BDT was used in situation of impassable stent among 37 patients.ResultsThe mean age of patients was 75.4 ± 6.5 years. The commonest clinical presentation was chronic coronary syndrome (n = 19; 51.3%) followed by non-ST-segment elevation myocardial infarction (NSTEMI) (n = 9; 24.4%), ST-segment elevation myocardial infarction (STEMI) (n = 5; 13.5%), and unstable angina (UA) (n = 10; 10.8%). Type B2 lesion was commonest (45.9%) followed by type C (35.2%) and B1 (18.9%). The commonest indication for BDT was angulation (n = 10; 27.1%) followed by tortuosity (n = 9; 24.3%), chronic total occlusion (n = 8; 17.9%), calcification (n = 7; 18.9%), and distally located lesion (n = 3; 8.1%). The left circumflex artery (LCX) was the most commonly intervened artery (n = 16; 43.2%) followed by left anterior descending (n = 11; 29.7%) and right coronary artery (n = 10; 27.1%). Mean diameter and mean length of stents were 3.3 ± 0.9 mm and 18 ± 6 mm respectively. The mean diameter and mean length of deflection balloon were 3 ± 0.5 mm and 20 ± 5 mm respectively. Lesions were modified using aggressive pre-dilatation in all cases while 19.4% of lesion required cutting balloon for additional modification. Additional wire as buddy wire was used in 54% of cases while wire in main vessel acted as buddy wire in dedicated bifurcation stenting. Stent implantation was successful in 36 cases with success rate of 97.3%; while in one case, stent could not be delivered using BDT. Stent was finally delivered using GuideZilla mother-in-child catheter. Overall failure rate was 2.7% which was contributed by extreme tortuosity, angulation, and severe calcification.ConclusionsIn selected cases of impassable lesions; the deflection balloon technique may provide a simple, convenient, and inexpensive solution without further need of additional hardwares except a buddy wire and a balloon.

Abstract No. 64 Analysis of complications and unsuccessful embolization of pulmonary arteriovenous malformations

Embolotherapy is the standard treatment for pulmonary arteriovenous malformation (pAVM). The purpose of this study is to explore the reasons for unsuccessful embolization and complications associated with embolotherapy. This retrospective chart review study was approved by the IRB. Data were collected for all the embolization procedures that were performed at our institution for pulmonary AVM treatment between January 2003 and January 2020. All ages of both genders were included in the analysis. The reason for unsuccessful embolization and complications were recorded. One hundred and eighty-seven patients had a total of 341 embolization procedures at our institutions for the treatment of PAVM. There were 240 (70%) women and 101 (30%) men included with a mean age of 49 ± 18 and 38 ± 20 years, respectively. The average fluoroscopic time was 34 minutes (range 3.4 to 120 minutes). Of 341, 47(14%) procedures were unsuccessful. The reason for unsuccessful embolization were (in order of frequency): no PAVM detected on catheter angiogram (n = 17, 36%), pAVM too small to treat (n = 12, 25%), tortuous feeding artery causing technical difficulty assessing the artery (n = 7, 15%), No evidence of reperfusion on follow up pulmonary angiogram (that were done to detect reperfusion) (n = 6, 13%), systemic arterial supply to the pAVM causing vein to vein shunting (n = 3, 6%), patient’s condition (increased respiratory motion and intraprocedural bradycardia) aborting the procedure (n = 2, 4%). There were a total of 9 (2%) intraprocedural complications with 2 major complications aborting the embolotherapy. Embolization of pulmonary arteriovenous malformation is a very successful procedure with minor complications. The main reasons of unsuccessful embolotherapy are no evidence of pAVM during catheter angiogram, very small feeding artery size, and tortuous feeding artery.

Abstract No. 238 Causes of technical failure in bilateral prostatic artery embolization

Prostatic artery embolization (PAE) is generally an elective procedure completed for lower urinary tract symptoms (LUTS) in benign prostatic hyperplasia (BPH). Technical success has generally been defined by successful bilateral prostatic artery embolization. The largest study to date, performed by Pisco et al of 630 PAE patients, showed a technical success rate of 92.6% with 7.4% of patients receiving unilateral treatment, and 1.9% having bilateral technical failure. However, the specific causes of technical failure have been under-reported in the literature and may help inform clinicians of potential pitfalls. PAE cases from June of 2014 until August of 2020 at two hospitals in a tertiary academic health system were queried (n = 216). Patients were included in this study if they underwent elective PAE as a primary treatment for BPH and were excluded if they received emergent PAE for hematuria or for another indication (e.g., malignancy). For all consecutive patients meeting these inclusion criteria, demographic, baseline, procedural, and follow-up data were collected. Technical failure, defined as failure to achieve bilateral embolization and stasis of the prostatic artery, were noted. The query found 216 consecutive elective PAEs. Of these, 39 cases (18%) demonstrated technical failure. The causes for technical failure were variable. 14 cases (36%) led to technical failure due to anatomical anomalies in the patients, including tortuous arteries (n = 6), diminutive arteries (n = 1), the presence of accessory vessels (n = 4), or small caliber vessels (n = 2), and other anomalies (n = 2). Six cases (15%) were due to failure to visualize vessels. Six cases (15%) were due to spasm or stenosis of vessels. 13 cases (33%) were due to other causes, including difficulty of access, failure to catheterize, fluoroscopic time, or risk of non-target embolization. The specific causes of technical failure in PAE are poorly reported in the literature. In our study, we demonstrate that the most common contributory sources of technical failure in PAE include anatomical variation in patients, failure in visualization, and stenosis or spasm of vessels. Other technical causes accounted for the remaining cases. Our study demonstrates the need for further research to elucidate the more precise causes of technical failure in PAEs.

Rota-Lithotripsy-A Novel Bail-Out Strategy for Calcified Coronary Lesions in Acute Coronary Syndrome. The First-in-Man Experience.

Heavy calcification remains one of the greatest challenges in the treatment of coronary artery disease (CAD), especially in subjects with an acute coronary syndrome (ACS). In the present case series study of high-risk patients with ACS, including both STEMI and NSTEMI, we performed a rota-lithotripsy—a combination of rotational atherectomy with subsequent intravascular lithotripsy—as a novel bail-out strategy to facilitate stent delivery in a tortuous calcified coronary artery.

Hemifacial spasm caused by a tortuous recurrent perforating artery: A case report

IntroductionWhen the culprit vessel in hemifacial spasm (HFS) is hard to determine, this is a challenge in microvascular decompression (MVD) surgery. In such a situation, small arteries such as perforators to the brainstem might be suspected. But small arteries are omnipresent near the facial nerve root exit/entry zone (fREZ). How to decide whether a given small artery is responsible for HFS is unclear. MethodWe report a case with a previously unreported form of neurovascular impingement, in which the culprit was found to be the recurrent perforating artery (RPA) from the anterior inferior cerebellar artery (AICA). An aberrant anatomic configuration of the RPA was found intraoperatively, which we thought was responsible for generating focal pressure on the facial nerve. Case reportA 62-year-old woman presented with a 1-year history of paroxysmal but increasingly frequent twitching in her right face. MRI showed tortuosity of the vertebral artery and apparently marked neurovascular impingement on the asymptomatic left side, while only the right AICA could be implicated as the possible culprit. Hemifacial spasm was diagnosed based on the typical clinical manifestation, and MVD was performed. The pre-meatal segment of the AICA was found not to be impinging the facial nerve at any susceptible portion near the fREZ: root exit point, attached segment, or root detachment point. The real culprit was in fact the RPA. This occult culprit vessel was tortuous, forming a coil-shaped twist which was interposed between the facial nerve and the intermediate nerve near the root detachment point. Focal pressure atrophy of the nerve was clearly observed at the compressing site. The patient achieved total spasm relief immediately after surgery, and remained spasm-free at 1-year follow-up, without any postoperative complications. ConclusionMVD is the only curative treatment for hemifacial spasm, but with a failure rate of around 10%. Mistaking the real culprit has been reported to be the most likely reason for surgical failure. Therefore, intraoperative identification of atypical occult forms of vascular compression is of importance to improve surgical outcome. In the present case, the RPA formed a coil-shaped twist, which inflicted focal vascular compression causing hemifacial spasm. We recommend careful inspection of the recurrent perforating artery during MVD for HFS, and decompressing any such neurovascular impingement.

Visible bigeminal pulses with tortuous common carotid artery

An 84-year-old woman with a history of hypertension, diabetes mellitus, dyslipidaemia and aortic stenosis (AS) was referred to our hospital for transcatheter aortic valve implantation (TAVI). She occasionally recognised dyspnoea...

Editor's Choice – Mid Term Outcomes of Crossed Limb vs. Standard Limb Configuration in Endovascular Abdominal Aortic Aneurysm Repair: A Propensity Score Analysis

The aim was to compare mid term outcomes between crossed limb (CL) and standard limb (SL) configuration in patients who underwent endovascular aortic aneurysm repair (EVAR). This was a comparative cohort study. Eligible patients who underwent EVAR between September 2011 and March 2019 in a tertiary academic centre were included. Inverse probability of treatment weighting (IPTW) was used to balance the demographic, anatomical and operative baseline characteristics between the two groups. The primary outcome was adverse limb events including type IB endoleak (T1BEL), type III endoleak, and limb occlusion. Cox proportional hazards regression and marginal structural model were performed to compare time to event outcomes. The study included 729 patients (194 CL and 535 SL) with a median follow up of 34 months (interquartile range 16 - 62 months). The weighted analyses revealed no significant difference between CL and SL EVAR in terms of adverse limb events, type IA endoleak (T1AEL), type II endoleak (T2EL), re-intervention, and overall survival. In the subgroup analysis of large aneurysm sac, the CL configuration was associated with a significantly decreased risk of T1BEL (hazard ratio [HR] 0.31, 95% confidence interval [CI] 0.12 - 0.78, p= .014). Similar results were also observed in the subgroup of tortuous iliac arteries (HR 0.30, 95% CI 0.11 - 0.81, p= .017). After stratification by severe neck angulation, no significant difference was found between CL and SL EVAR for T1AEL, but the CL configuration was associated with a significantly increased risk of re-intervention (HR 2.69, 95% CI 1.31 - 5.51, p= .007). In addition, a trend towards a higher risk of adverse limb events in the CL group with severely angulated proximal neck was observed. CL configuration in EVAR is safe and may be associated with a lower risk of T1BEL in patients with a large aneurysm sac or tortuous iliac arteries. However, it should be applied cautiously to aneurysms with a severely angulated neck due to the potentially higher risk of re-intervention.

Location of the abducens nerve stretched by a tortuous vertebrobasilar artery in trigeminal neuralgia.

Trigeminal neuralgia (TGN) caused by the vertebrobasilar artery (VBA) is uncommon. The abducens nerve root is frequently dislocated by a tortuous VBA near the trigeminal nerve root. This unusual location of the root is not well known. This study aimed to investigate the location of the stretched abducens nerve root. The objective is 26 patients with VBA-related TGN who underwent microvascular decompression (MVD). We retrospectively investigated the course of the abducens nerve root with magnetic resonance imaging (MRI) with three-dimensional (3D) imaging and surgical findings. The displacement of the abducens nerve root on the affected side was compared to the contralateral side. The abducens nerve root was distorted by a tortuous VBA (46.2%) or the anterior inferior cerebellar artery (53.8%). The average length of the cisternal segment was stretched to 23.4 mm versus 12.4 mm on the contralateral side. The peak point of the elevated abducens nerve root was mostly located rostro-medial (65.4%) or caudo-medial (34.6%) to the neurovascular compression site of the trigeminal nerve with a mean distance of 9.1 mm. Contact with the trigeminal nerve root was observed in 7 patients (26.9%). Three-dimensional imaging was consistent with the surgical findings and useful in predicting the location of the abducens nerve root. No abducens nerve palsy was noted in our series. The abducens nerve root is located near the trigeminal nerve root in VBA-related TGN. Preoperative understanding of the unusual course of the abducens nerve root contributes to avoiding accidental nerve injury during MVD.

Pull-Through Buddy Wire Technique for Endovascular Thrombectomy in Patients with Acute Ischemic Stroke: Technical Note.

Excessive tortuosity is a notable cause of failed endovascular thrombectomy for acute large-vessel occlusion stroke. Transcervical access (TCA) is a commonly proposed solution for overcoming this difficulty. However, the large-bore catheter usually used in TCA increases the risk of serious local complications. This paper presents a modified technique for TCA that uses a pull-through buddy wire (PTBW) to track a large-bore femoral guiding sheath (GS) into the carotid artery via a small carotid puncture site. The carotid puncture site can be easily managed through gentle manual compression. Two illustrative cases using this technique to deal with a large aortic arch and tortuous left common carotid artery are reported. In both cases, recanalization was achieved after successful GS placement. Using a PTBW is feasible in TCA.

Surgical treatment for anomalous origin of the right coronary artery from the pulmonary artery: a case report with five-year follow-up

BackgroundAnomalous origin of the right coronary artery from the pulmonary artery (ARCAPA) is a rare congenital heart disease affecting about 0.002% of the population. Knowledge of ARCAPA is almost collected from case reports. The aim of this study was to provide a rare case to better understand this rare congenital coronary anomaly.Case presentationWe report a rare case of an 18-year-old male who was initially referred because of heart murmur. Dilated and tortuous coronary arteries were detected by echocardiography and congenital coronary anomaly was suggested. Further coronary CT angiography confirmed the diagnosis of ARCAPA. Although dual coronary system provides favorable long-term outcome, bypass surgery was considered technically difficult due to the huge mismatch of caliber between the right coronary artery and graft vessels. Eventually, simple right coronary artery ligation was performed. The patient was followed up for about 5 years without evidence of atherosclerosis or myocardial ischemia.ConclusionsARCAPA presents as a rare congenital heart disease with variable clinical manifestations. Surgical treatment is highly recommended to re-establish dual coronary system and prevent further complications. To our best knowledge, only about 200 cases of ARCAPA has been reported.

Dieulafoy lesions as cause of upper gastrointestinal bleeding in a patient with portal hypertension

ABSTRACT Dieulafoy’s lesion is an abnormally large and tortuous submucosal artery that protrudes through a small mucosal defect resulting in gastrointestinal bleeding. We present a case of a 53-year-old man with a history of HIV and alcohol abuse who presented to the emergency room with hematemesis and melena. Upper endoscopy revealed an actively bleeding dieulafoy lesion, but due to uncontrolled bleeding, embolization of the left artery was necessitated. The incidence of dieulafoy lesions is about 0.3% to 6.7% within the stomach. The etiology remains uncertain but has been linked to alcoholism and antiplatelet drugs. We are emphasizing the importance of considering uncommon causes of upper gastrointestinal bleeding in patients with portal hypertension.

Microcatheter Re-Shaping Using Fusion Image in Coil Embolization: A Technical Note.

We report the utility of microcatheter reshaping by referring to fusion images with 3D-DSA and microcatheter 3D images made using non-subtraction and non-contrast (non-SC) rotational images. Case 1: The patient was a 74-year-old man who had an internal carotid-anterior choroidal artery bifurcation aneurysm with a tortuous proximal parent artery. The initial attempt to introduce the microcatheter into the aneurysm was unsuccessful. During this unsuccessful microcatheter introduction, we created fusion images with 3D-DSA and microcatheter 3D images by acquiring positional information of the microcatheter using the non-SC method. By reshaping the microcatheter with reference to the fusion images, the direction of the distal end of the microcatheter was reshaped to be in accordance with the long axis of the aneurysm, a shape more suitable for coiling. Case 2: The patient was a 47-year-old man who had an anterior communicating (A-com) artery aneurysm with two daughter sacs. We successfully placed two microcatheters in the direction of each sac to make more stable framing by referring to 3D fusion images after the first microcatheter was positioned. In both cases, microcatheter reshaping was necessary because of the vessel and aneurysm anatomy. We have used this technique successfully in 15 patients, for both ruptured and unruptured aneurysms. The average number of microcatheter reshaping was 1.3 times. This method provides effective microcatheter reshaping for coil embolization of aneurysms, particularly those with differences between the axis of the parent artery and the vertical axis of aneurysm, or with a tortuous proximal artery.

Morphohistological analysis of the prevalence and distribution of atheroma in the abdominal aorta and its branches: a cadaveric study.

BackgroundAneurysms and atheromatous processes are prominent pathological features that are commonly associated with significant morbidity and mortality.ObjectivesThis cadaveric study was conducted to evaluate the morphometric and histological aspects of atheromatous plaque formation in abdominal aortas and their branches and their associated morphological variations, if present, characterized by loops, kinking, or tortuosity.MethodsThe study was performed using 30 human cadavers (approx. 65-75 years). Frequency of occurrence of calcified plaques in the abdominal aorta and its branches and their morphometric measurements were noted and histological features were observed with the aid of Hematoxylin & Eosin staining.ResultsVariations in the abdominal aorta and the common iliac artery were observed in 16.6% of specimens. Atheromatous plaque formation was seen in 2 specimens (1 specimen was associated with kinking) while in 3 other specimens only variation in normal structure (kinking/ tortuous artery) was observed. Histological analysis showed foamy macrophages and dense calcification, giving an atheromatous appearance.ConclusionsCadaveric reports of the location, nature, and degree of plaque formation in the abdominal aorta and its branches are extremely important in clinical settings and for choosing treatment options.

Carotid Artery Stenting Using the Snake Hunt Technique for Highly Tortuous Carotid Artery Stenosis: A Technical Note.

In carotid artery stenting (CAS) for highly tortuous carotid stenosis, it is often difficult to guide rigid devices such as carotid stents. There are various adjunctive techniques using a guidewire: the buddy wire technique, the sheep technique, and the stiff guide technique. We report a case in which the tortuous vessel was straightened and a stent could be inserted. A 64-year-old man with amaurosis had highly tortuous left carotid stenosis. Despite the best medical treatments, he often had transient cerebral ischemic symptoms, so we planned CAS. We could insert the first stent, but the proximal vessel was kinked by the placement of the stent. It was so tortuous that the second stent could not be inserted by adjunctive techniques. Therefore, the proximal balloon was inflated and pulled back to straighten the tortuous vessel, and then we could insert the stent. We named this technique the “snake hunt technique” because it was just like catching a snake given that the tortuous vessel was stretched. This technique could be a troubleshooting step when it is difficult to insert a stiff device such as a stent or balloon even with the use of various adjunctive techniques.

Numerical study on flow topology and hemodynamics in tortuous coronary artery with symmetrical and asymmetrical stenosis

Tortuosity in coronary artery has been found to be greatly related to the potential sites of stenosis in these last years. Many investigations have been carried out based on the tool of Computational Fluid Dynamics (CFD) mainly focusing on the influences of curved artery in blood flow. Within the limited investigations of coupling between stenosis and tortuosity, the stenosis has been considered to be located at the tortuous segment. However, with recent clinical studies, the case of stenosis occurred at non-tortuous segment before tortuosities has been confirmed which has not been paid enough attention yet. Therefore, the present study aims to investigate the disturbed streamlines and hemodynamics in curved and spiral artery considering symmetrical and asymmetrical stenosis upstream these tortuosities. Different stenosis severities, pulse rates and distances between stenosis and tortuosity as controlling parameters have been studied. The distribution of time averaged wall shear stress (TAWSS) and streamlines through tortuous segment have been displayed in order to determine the potential disease sites. Artery surface of TAWSS below critical value has been quantified as well to evaluate the risks of atherosclerosis. The results reveal that larger artery surface of TAWSS below critical value generally goes with smaller pulse rate, larger stenosis severity and distance between stenosis and tortuosity both for curved and spiral artery. However, exceptions were found in the cases of distance of 6 mm in curved artery with symmetrical stenosis and stenosis severity of 50% in spiral artery. Moreover, the spiral tortuosity tends to suppress the potential risks of atherosclerosis compared to curved tortuosity.