scholarly journals Feasibility Study on Stereotactic Radiotherapy for Total Pulmonary Vein Isolation in A Canine Model

Author(s):  
Ji Hyun Chang ◽  
Myung-Jin Cha ◽  
Jeong-Wook Seo ◽  
Hak Jae Kim ◽  
So-Yeon Park ◽  
...  

Abstract We tested the feasibility of pulmonary vein (PV) and left atrial (LA) posterior wall isolation using non-invasive stereotactic ablative body radiotherapy (SABR) and investigated pathological changes in irradiated lesions in a canine model. Seven male Mongrel dogs received single-fraction 33-Gy SABR. We designed the en-bloc circular target of total PVs and LA posterior wall to avoid the esophagus. The circular box lesion included the LA roof and ridge, low posterior wall, and posterior interatrial septum. At 6 weeks or 4 months post-SABR, electrical isolation of the SABR lesion was confirmed using LA posterior wall pacing, and histopathological review was performed. Electrical isolation of all PVs and the LA posterior wall was achieved in three of five dogs in the 4-month group. There was one target failure and one sudden death at 15 weeks. Although two dogs in the 6-week group failed to achieve electrical lesion isolation, the irradiated atrial myocardium showed diffuse hemorrhage with inflammatory cell infiltration. In successfully isolated 4-month model dogs, we observed transmural necrotic scarring with extensive fibrosis on irradiated atrial tissue. The findings suggest that this novel circular box-design radiotherapy technique using SABR could be applied to humans after further studies are conducted to confirm safety.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ji Hyun Chang ◽  
Myung-Jin Cha ◽  
Jeong-Wook Seo ◽  
Hak Jae Kim ◽  
So-Yeon Park ◽  
...  

AbstractWe tested the feasibility of pulmonary vein (PV) and left atrial (LA) posterior wall isolation using non-invasive stereotactic ablative body radiotherapy (SABR) and investigated pathological changes in irradiated lesions in a canine model. Seven male Mongrel dogs received single-fraction 33 Gy SABR. We designed the en-bloc circular target of total PVs and LA posterior wall to avoid the esophagus. The circular box lesion included the LA roof and ridge, low posterior wall, and posterior interatrial septum. At 6 weeks or 4 months post-SABR, electrical isolation of the SABR lesion was confirmed using LA posterior wall pacing, and histopathological review was performed. Electrical isolation of all PVs and the LA posterior wall was achieved in three of five dogs in the 4-month group. There was one target failure and one sudden death at 15 weeks. Although two dogs in the 6-week group failed to achieve electrical lesion isolation, the irradiated atrial myocardium showed diffuse hemorrhage with inflammatory cell infiltration. In successfully isolated 4-month model dogs, we observed transmural fibrotic scarring with extensive fibrosis on irradiated atrial tissue. The findings suggest that this novel circular box-design radiotherapy technique using SABR could be applied to humans after further studies are conducted to confirm safety.


Author(s):  
Martin Eichenlaub ◽  
Bjoern Mueller-Edenborn ◽  
Jan Minners ◽  
Martin Allgeier ◽  
Heiko Lehrmann ◽  
...  

Abstract Background Relevant atrial cardiomyopathy (ACM), defined as a left atrial (LA) low-voltage area ≥ 2 cm2 at 0.5 mV threshold on endocardial contact mapping, is associated with new-onset atrial fibrillation (AF), higher arrhythmia recurrence rates after pulmonary vein isolation (PVI), and an increased risk of stroke. The current study aimed to assess two non-invasive echocardiographic parameters, LA emptying fraction (EF) and LA longitudinal strain (LAS, during reservoir (LASr), conduit (LAScd) and contraction phase (LASct)) for the diagnosis of ACM and prediction of arrhythmia outcome after PVI. Methods We prospectively enrolled 60 consecutive, ablation-naive patients (age 66 ± 9 years, 80% males) with persistent AF. In 30 patients (derivation cohort), LA-EF and LAS cut-off values for the presence of relevant ACM (high-density endocardial contact mapping in sinus rhythm prior to PVI at 3000 ± 1249 sites) were established in sinus rhythm and tested in a validation cohort (n = 30). Arrhythmia recurrence within 12 months was documented using 72-h Holter electrocardiograms. Results An LA-EF of < 34% predicted ACM with an area under the curve (AUC) of 0.846 (sensitivity 69.2%, specificity 76.5%) similar to a LASr < 23.5% (AUC 0.878, sensitivity 92.3%, specificity 82.4%). In the validation cohort, these cut-offs established the correct diagnosis of ACM in 76% of patients (positive predictive values 87%/93% and negative predictive values 73%/75%, respectively). Arrhythmia recurrence in the entire cohort was significantly more frequent in patients with LA-EF < 34% and LASr < 23.5% (56% vs. 29% and 55% vs. 26%, both p < 0.05). Conclusion The echocardiographic parameters LA-EF and LAS allow accurate, non-invasive diagnosis of ACM and prediction of arrhythmia recurrence after PVI. Graphic abstract


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
Y Matsunaga ◽  
Y Egami ◽  
M Yano ◽  
M Yamato ◽  
R Shutta ◽  
...  

Abstract Background It has been reported that elimination of non-pulmonary vein (PV) triggers after PV isolation is a good predictor of atrial tachyarrhythmia free survival. However, precise mapping of triggers outside from superior vena cava (SVC) or left atrial posterior wall (LAPW) are difficult. The aim of this study is to assess the efficacy of self-reference mapping technique to eliminate non-PV triggers originated from outside of primordial pulmonary vein area. Methods Total of 431 patients (446 procedures) underwent atrial fibrillation (AF) ablation in a hospital and in a medical center from January 2017 to March 2019. After isolation of PV, non-PV triggers were induced with isoproterenol and/or adenosine triphosphate. Reproducible non-PV triggers were targeted to ablate using following self-reference mapping technique: A trigger conducts centrifugally and the earliest site should be distinguished from other later activated sites. Using a PentaRay multipolar catheter, the operators annotated the earliest site of local activation and a reference tag was placed. The multipolar catheter was then moved to the reference tag and the process repeated. Ultimately, we identified clusters of early circumferential activation and ablated. Results A total of 32 non-PV triggers excluding the origin from LAPW and SVC were induced in 23 patients. Nineteen triggers (59%) were located in the right atrium and 13 triggers (41%) in the left atrium (Figure 1). All triggers were eliminated with ablation and AF was non-inducible in all patients at the end of the procedure. During the follow-up (529±270 days), 18 patients (77%) were free from atrial tachyarrhythmias after a 3-month blanking period. Three patients received additional ablation procedures for recurrent atrial arrhythmias. No non-PV triggers ablated during the previous procedure were observed. Conclusion A novel self-reference mapping technique is useful for eliminating non-PV triggers in terms of the short- and long-term success. Figure 1. Distribution of non-PV triggers Funding Acknowledgement Type of funding source: None


2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
D. O. Kavanagh ◽  
H. Imran ◽  
A. Almoudaris ◽  
P. Ziprin ◽  
O. Faiz

A 72-year-old female presented with a six-month history of increased frequency of defecation, rectal bleeding, and severe rectal pain. Digital rectal examination and endoscopy revealed a low rectal lesion lying anteriorly. This was confirmed histologically as adenocarcinoma. Radiological staging was consistent with a T3N2rectal tumour. Following long-course chemoradiotherapy repeat staging did not identify any metastatic disease. She underwent a laparoscopic cylindrical abdominoperineal excision withen blocresection of the coccyx and posterior wall of the vagina with a negative circumferential resection margin. The perineal defect was reconstructed with Permacol (biological implant, Covidien) mesh. She had no clinical evidence of a perineal hernia at serial followup. Dynamic MRI images of the pelvic floor obtained during valsalva at 10 months revealed an intact pelvic floor. A control case that had undergone a conventional abdominoperineal excision with primary perineal closure without clinical evidence of herniation was also imaged. This confirmed subclinical perineal herniation with significant downward migration of the bowel and bladder below the pubococcygeal line. We eagerly await further evidence supporting a role for dynamic MR imaging in assessing the integrity of a reconstructed pelvic floor following cylindrical abdominoperineal excision.


Author(s):  
Raffaele Manta ◽  
Angelo Zullo ◽  
Donato Alessandro Telesca ◽  
Danilo Castellani ◽  
Ugo Germani ◽  
...  

Abstract Background and Aims Ulcerative colitis [UC] patients are at an increased risk of developing colorectal cancer due to chronic inflammation. Endoscopic submucosal dissection [ESD] allows removal of non-invasive neoplastic lesions in the colon, but few data are available on its efficacy in UC patients. Methods Data from consecutive UC patients diagnosed with visible dysplastic lesions in the colon who underwent ESD were evaluated. The en bloc removal, R0 resection and complication rates were calculated. Local recurrence and metachronous lesions during follow-up were identified. A systematic review of the literature with pooled data analysis was performed. Results A total of 53 UC patients [age: 65 years; range 30–74; M/F: 31/22] underwent ESD. The en bloc resection rate was 100%, and the R0 resection rate was 96.2%. Bleeding occurred in seven [13.2%] patients, and perforation in three [5.6%] cases, all treated at endoscopy. No recurrence was observed, but two metachronous lesions were detected. Data from six other studies [three Asian and three European] were available. By pooling data, en bloc resection was successful in 88.4% (95% confidence interval [CI] = 83.5–92) of 216 lesions and in 91.8% [95% CI = 87.3–94.8] of 208 patients. R0 resection was achieved in 169 ESDs, equivalent to a 78.2% [95% CI = 72.3–83.2] rate for lesions and 81.3% [95% CI = 75.4–86] rate for patients. No difference between European and Asian series was noted. Conclusions This pooled data analysis indicated that ESD is a suitable tool for safely and properly removing non-invasive neoplastic lesions on colonic mucosa of selected UC patients.


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