Soft tissue vascular tumor-like lesions in adults: imaging and pathological analysis pitfalls per ISSVA classification.

OBJECTIVES: To compare the magnetic resonance imaging (MRI) and Doppler ultrasound (DUS) findings with the pathological findings of soft tissue vascular tumors (STVTs) according to the 2018 ISSVA (International Society for the Study of Vascular Anomalies) classification to differentiate vascular tumors from vascular malformations. METHODS: This retrospective study included patients with STVTs who underwent contrast-enhanced MRI and pathological analysis at our hospital between 2010 and 2020. The presumptive diagnosis based on the on-site imaging and histological analysis was compared with imaging and histological analysis conducted off-site utilizing the ISSVA criteria. RESULTS: This study included 31 patients with 31 vascular tumors located in the head and neck (n = 3), trunk (n = 2), and extremities (n = 26). The off-site pathological analysis confirmed benign vascular tumors in 54.8% of cases (non-involuting congenital hemangioma: 35.5%; epithelioid hemangioma: 13%; pyogenic granuloma: 3%; and spindle cell hemangioma: 3%). Based on the off-site histological analysis, 25.8% were reclassified as having a vascular malformation whereas three had other benign lesions. Only phleboliths were associated with a vascular malformation (p = 0.03). The concordance between off-site MRI and pathological findings was fair (k = 0.3902 (0.0531-0.7274)), whereas that between on-site and off-site pathological analyses was poor (k = -0.0949 (-0.4661 to 0.2763)). CONCLUSION: Benign vascular tumors have non-specific imaging features on imaging with some overlap with atypical vascular malformations. Therefore, histological analysis is recommended. Imaging and pathological analyses should be performed in accordance with the ISSVA classification to minimize inter-observer discrepancies. CRITICAL RELEVANCE STATEMENT: Imaging features of benign vascular tumors on MRI are non-specific, leading to discrepancies with pathological findings and potential overlap with atypical vascular malformations. Imaging and histological analyses should be performed in accordance with ISSVA guidelines to improve patient management. KEY POINTS: The imaging features of benign vascular tumors are non-specific. Histological analysis is recommended for soft tissue vascular tumors in adults. Analyses of soft tissue vascular tumors should be performed in accordance with ISSVA guidelines.

Embolization in pelvic venous disorders using ethylene vinyl alcohol copolymer (Onyx®) and Aetoxysclerol: a prospective evaluation of safety and long-term efficacy.

OBJECTIVES: To prospectively evaluate the safety and efficacy of embolization using ethylene vinyl alcohol copolymer (Onyx®) and Aetoxysclerol for treatment of pelvic venous disorders (PeVD). METHODS: This prospective study was approved by the institutional ethics review board. Ten clinical parameters were retained for evaluation of PeVD (pelvic pain, dyspareunia, post-coital pain, menstruation pain, lower limbs pain, difficulty walking, aesthetic discomfort, impact on daily working life, psychological impact and impact on daily life), measured on a visual analogue scale (VAS) between 0 and 10, and a global score out of 100 was noted before embolization, after 3 months during the imaging follow-up, and at the end of follow-up by phone call. The main criterion was clinical efficacy of embolization defined by an impairment score < 40/100 and a 50% decrease in overall score. Complications were recorded. Visualization of Onyx® on MRI 3 months after embolization was noted. RESULTS: Between July 2017 and May 2019, 73 consecutive women (mean age ± SD [range]: 41 ± 11 years [25-77]) treated by embolization with Onyx® and Aetoxysclerol were included. The median follow-up was 28 months [Q1-Q3: 24.0-29.2] (range: 18.1-34.5). The median initial VAS impairment score was 39/100 [29.75-48.50] (12-58). Clinical efficacy was obtained for 70 patients (70/73, 95.9%), and the median VAS impairment score at the end of follow-up was significantly lower at 3 [0.00-7.25] (0-73) (p < 0.0001). Four minor complications occurred. Onyx® was visualized on DIXON sequence of MRI for all patients. CONCLUSION: Embolization using Onyx® and Aetoxysclerol for PeVD is safe and effective. KEY POINTS: • Embolization using Onyx® and Aetoxysclerol for pelvic venous disorders is safe and effective. • Imaging follow-up is facilitated by visualization of Onyx® on MRI DIXON sequences.

MRI associated factors of clinical efficacy of embolization in patients with pelvic venous insufficiency.

PURPOSE: The purpose of this study was to identify anatomical findings at magnetic resonance imaging (MRI) associated with successful percutaneous embolization in women with pelvic venous insufficiency (PVI). MATERIAL AND METHODS: Between 2008 and 2018, 168 consecutive women (mean age, 39±9 [SD] years; range: 21-69 years) who underwent percutaneous embolization for PVI confirmed by MRI and phlebography were included. Clinical efficacy of embolization was evaluated by patients' opinion or visual analogue scale. Associated factors of success of embolization were searched by comparing MRI findings in women with successful embolization with those in women with failed embolization using univariate analyses. RESULTS: The mean follow-up was 36±29 (SD) months (range: 12-138 months). Clinical efficacy of embolization was obtained in 126/168 women (75%), complete symptom improvement in 33/168 women (20%) and significant partial improvement in 92/168 women (55%). No symptom improvement and symptoms exacerbation were observed in 17/168 (10%) and 2/168 (1%) women, respectively. At univariate analysis, right ovarian vein diameter≤7mm and vulvar varicosities were associated with successful embolization (P=0.04 and P=0.01, respectively) and left ovarian vein diameter≤7mm was associated with a complete improvement of symptoms (P=0.03). At multivariate analysis, a small right ovarian vein diameter was the single MRI variable associated with clinical efficacy of embolization (P=0.04). CONCLUSION: Small ovarian vein diameters on MRI are associated with best clinical efficacy of percutaneous embolization in PVI. Right ovarian vein diameter>7mm should warrant further phlebography to exclude venous insufficiency.

Proximal embolization of splenic artery in acute trauma: Comparison between Penumbra occlusion device versus coils or Amplatzer vascular plug.

PURPOSE: To compare intervention duration and fluoroscopy time for proximal embolization of splenic arteries in acute trauma using the Penumbra occlusion device (POD®), coils or Amplatzer™ vascular plug (AVP). MATERIAL AND METHODS: A total of 29 patients with splenic injury without vascular injury who were treated by proximal splenic artery embolization using POD® (n=12), coils (n=9) or AVP (n=8) were retrospectively included. There were 25 men and 4 women with a median age of 34 years (range: 10-69 years). To overcome bias in treatment choice, a propensity score was used using inverse probability weighting. Intervention duration and fluoroscopy time, treatment success and complications were compared. RESULTS: The median intervention duration was significantly shorter using POD® (30min) or AVP (47min) than using coils (60min) (P=0.0001 and 0.004, respectively). The median fluoroscopy time was significantly lower using POD® (11.5min) than using coils (23.6min) (P=0.0076) or AVP (16.5min) (P=0.049). The primary efficacy rate was 100% with POD® and AVP and 89% with coils (P=0.586). Six complications occurred with a mean follow-up of 12 months for POD®, 32 months for coils and 40 months for AVP, consisting in 2 abscesses treated by anti-biotherapy with POD®, one abscess with AVP, 2 material migrations with coils and 1 coil dismantled without consequence. CONCLUSION: POD® and AVP allow proximal embolization of splenic artery in acute trauma with shorter intervention duration by comparison with conventional metallic coils with similar technical success. POD® allows a shorter fluoroscopy time than coils or AVP.

In vivo percutaneous microwave ablation in kidneys: Correlation with ex vivo data and ablation work.

PURPOSE: To compare diameters of in vivo microwave ablation (MWA) performed in swine kidneys with ex vivo diameters, and to correlate with ablation work (AW), a new metric reflecting total energy delivered. MATERIAL AND METHODS: Eighteen in vivo MWA were performed in 6 swine kidneys successively using one or two antennas (MicroThermX®). Ablation consisted in delivering power (45-120W) for 5-15minutes. Ex vivo diameters were provided by the vendors and obtained on bovine liver tissue. AW was defined as the sum of (power)*(time)*(number of antennas) for all phases of an ablation (in kJoules). Kidneys were removed laparoscopically immediately after ablation. After sacrifice, ablations zones were evaluated macroscopically, and maximum diameters of the zones were recorded. Wilcoxon sum rank test and Pearson's correlation were used for comparisons. RESULTS: For a single antenna (n=12), the in vivo diameters ranged from 12 to 35mm, and 15-49mm for 2 antennas (n=6). The in vivo diameters remained shorter than ex vivo diameters by 8.6%±30.1 on 1 antenna and 11.7%±26.5 on 2 antennas (P=0.31 and 0.44, respectively). AW ranged from 13.5 to 108kJ. Diameters increased linearly with AW both with 1 and 2 antennas, but only moderate correlations were observed (r=0.43 [95% confidence interval: -0.19; 0.81], P=0.16; and 0.57 [-0.44; 0.95], P=0.24, respectively). CONCLUSION: Although diameters after in vivo renal MWA increased linearly with AW, the moderate correlation and wide standard deviations observed may justify a careful imaging monitoring during treatment delivery and settings adaptation, if needed, for optimal ablation.

Percutaneous image-guided biopsies of small renal tumors: Current practice and perspectives.

Percutaneous image-guided biopsies help better select patients with renal tumors smaller than 4cm. These biopsies are performed to reduce the risks of overtreatment and to discriminate between patients who need ablation therapy and those who require active surveillance. Percutaneous image-guided biopsies are effective for a definitive diagnosis with little risk of complications when cautions are observed. With the current addition of multiparametric imaging, standardized biopsy protocols may further help adapt therapeutic decisions. The aim of this review is to report the current indications and techniques of biopsy performed in case of small solid renal masses and to clarify the optimal conditions for the realization of these biopsies.

Embolization of ovarian vein for pelvic congestion syndrome with ethylene vinyl alcohol copolymer (Onyx®).

PURPOSE: To evaluate the safety and efficacy of pelvic embolization using ethylene vinyl alcohol copolymer (Onyx®) for pelvic congestion syndrome. MATERIAL AND METHODS: Between March 2012 to September 2016, 17 women (mean age, 44.7± 12.2 (SD) years; range: 34-71years) presenting with pelvic congestion syndrome were evaluated for transvenous embolization with Onyx®. Pelvic congestion syndrome was initially diagnosed by clinical examination and the results of transvaginal Doppler ultrasound and further confirmed by pelvic venography. Primary and secondary clinical efficacy was defined respectively by the resolution of the symptoms after embolization and at the end of the follow-up, irrespective to the number of embolization procedures. RESULTS: Technical efficacy of embolization was 100% with no significant complications during and after embolization. After a mean follow-up time of 24.2 months (range: 6-69months) a primary and secondary clinical efficacy of 76.4% (13/17 women) and 94.1% (16/17 women) respectively were observed. Four women (23.5%) underwent a second embolization procedure with one woman requiring a third embolization procedure. These additional embolization procedures were associated with direct puncture of vulvar varices for sclerotherapy in two women. Five women (29%) had recurrent symptoms 21 months post-treatment (7-42months). CONCLUSION: Pelvic embolization using ethylene vinyl alcohol copolymer (Onyx®) has a favorable clinical success for pelvic congestion syndrome.

Embolization for persistent type IA endoleaks after chimney endovascular aneurysm repair with Onyx®.

PURPOSE: The purpose of this study was to determine retrospectively the safety and technical success rate of embolization using ethylene vinyl alcohol copolymer (Onyx®) for persistent type 1A endoleaks after chimney endovascular aneurysm repair (EVAR) for complex aortic aneurysms. MATERIAL AND METHODS: Nine consecutive patients (6 men, 3 women) with a mean age of 78.6 years (range: 62-87 years) presenting with persistent type IA endoleaks after chimney EVAR and an increase of aneurysm size were treated using transarterial embolization with Onyx®. RESULTS: Technical success was obtained in all patients (100%) and no complications were observed. Mean follow-up was 16 months (range: 3-35 months). Primary clinical efficacy was obtained for 8/9 patients (89%) and primary technical efficacy for 6/9 patients (67%). Secondary clinical efficacy was 100%, and secondary technical efficacy was 78%. CONCLUSION: Our results suggest that arterial embolization using Onyx® appears as a feasible and safe endovascular procedure of type IA endoleaks after chimney EVAR, although further validation is now required.

Safety and efficacy of embolization using Onyx® of persistent type II endoleaks after abdominal endovascular aneurysm repair.

PURPOSE: To retrospectively evaluate the safety and efficacy of embolization of persistent type II endoleaks occurring after abdominal endovascular aneurysm repair (EVAR) using ethylene vinyl alcohol copolymer (Onyx®). MATERIAL AND METHODS: Between 2008 and 2016, 28 consecutives patients (25 men, 3 women) with a mean age of 75.3years±9 (SD) (range: 59-90years) were treated for 29 persistent type II endoleaks with increasing aneurysm size>5mm occurring after EVAR. A total of 35 embolization procedures were performed using Onyx®, via a transarterial route (n=25) or direct puncture (n=10), with or without additional metallic coils. The endpoints were to evaluate the clinical efficacy, corresponding to the stabilization or decrease of aneurism size, and the technical efficacy, corresponding to the ability to complete the embolization. RESULTS: No severe complications were observed during and after embolization. The primary and secondary clinical efficacies were 75% (21/28) and 96.4% (27/28), respectively. Overall primary technical efficacy rate was 58.6% (17/29), greater for transarterial technique (72.8%) than for direct puncture (14.3%) (P=0.01). Secondary technical efficacy was 72.4% (21/29), with no differences between transarterial (81.8%) and direct puncture (42.8%) (P=0.06). CONCLUSION: Embolization with Onyx® of type II endoleaks after EVAR appears a safe and effective procedure.

Microwave ablation of renal tumors: A narrative review of technical considerations and clinical results.

PURPOSE: The purpose of this review was to identify the specific technical considerations to adequately perform microwave ablations (MWA) of renal tumors and analyze the currently available clinical results. METHODS: Using Medline, a systematic review was performed including articles published between January 2000 and September 2016. English language original articles, reviews and editorials were selected based on their clinical relevance. RESULTS: MWA has several theoretical advantages over radiofrequency ablation in consistently providing higher intratumoral temperatures. MWA is less dependent of electrical conductivities of tissues and the delivered energy is less limited by desiccation of heated tissues. While there are insufficient data, especially because of a lack of studies with mid- to long-term follow-up, to determine the oncologic effectiveness of MWA, this technique appears safe and effective for the ablation of T1 renal tumors. There is evidence for using mid-level settings based on experimental and clinical data. Power set at 50-65W for 5-15min appears adequate in kidney but close clinical and imaging follow-up have to be performed. CONCLUSION: Renal MWA offers theoretical advantages by comparison with other available techniques to treat renal tumors. However, MWA suffers of less cumulative data compared to radiofrequency ablation or cryoablation. Moreover, microwaves still require further studies to identify the optimal tumor characteristics and device settings leading to predictable ablation.