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Percutaneous Cryoablation of Symptomatic Localized Venous Malformations: Preliminary Short-term Results
BRIEF REPORT
Percutaneous Cryoablation of Symptomatic Localized Venous Malformations: Preliminary Short-term Results Franc- ois Cornelis, MD, Marion Havez, MD, Christine Labreze, MD, Alain Taieb, MD, Binh N. Bui, MD, Dominique Midy, MD, and Nicolas Grenier, MD
ABSTRACT Short-term outcomes after percutaneous image-guided cryoablation of symptomatic venous malformations in four consecutive patients (mean age, 42.5 y) are reported. Two patients had local recurrences after previous treatment. Mean preoperative pain was estimated on a visual analog scale at 5 (range, 3–7). Cryoablation was performed in a single session under general anesthesia. Postoperative pain and superficial edema disappeared within 2 weeks. No pain was subsequently reported, and magnetic resonance imaging demonstrated a significant volume decrease at 3 months (75%; P ¼ .01) and at 6 months (95%; P ¼ .01). Percutaneous cryoablation shows promising local control in patients with symptomatic venous malformations.
Image-guided sclerotherapy and surgical resection are recognized as standard therapeutic options for venous malformations (1). However, therapeutic alternatives are being developed for recurrence after sclerotherapy or for vascular anomalies with mainly solid components such as fibroadipose vascular anomalies, which could be inaccessible by sclerotherapy. Childs and Emory (2) reported more recently the successful treatment of intramuscular venous malformation with image-guided radiofrequency ablation. Owing to its minimally invasive nature and as proposed for desmoid tumors occurring in soft tissue (3,4), cryoablation may also provide a promising alternative option for relieving symptoms of venous malformations affecting patients’ quality of life (5) because it causes less damage to surrounding tissues than surgery or radiofrequency ablation (6). Postoperative pain is mild and recovery is rapid after the procedure, which can be performed under local or general anesthesia (7). The purpose of this preliminary study was to report the short-term local control
From the Departments of Radiology (F.C., M.H., N.G.), Pediatric Dermatology (C.L.), Dermatology (A.T.), and Vascular Surgery (D.M.), Pellegrin Hospital, Place Ame´lie Raba Le´on, 33076 Bordeaux, France; and Departments of Radiology (F.C.) and Oncology (B.N.B.), Institut Bergonie´, Bordeaux, France. Received January 22, 2013; final revision received and accepted March 4, 2013. Address correspondence to F.C.; E-mail: francois.cornelis@ chu-bordeaux.fr None of the authors have identified a conflict of interest. & SIR, 2013 J Vasc Interv Radiol 2013; 24:823–827 http://dx.doi.org/10.1016/j.jvir.2013.03.005
after percutaneous image-guided cryoablation of localized symptomatic venous malformations.
MATERIALS AND METHODS Patients and Lesions The institutional review board approved this retrospective study. After discussion in a multidisciplinary team meeting involving dermatologists, surgeons, and radiologists, surgery was rejected for all four patients because of coexisting or expected major morbidity. Sclerotherapy was also rejected because of previous treatment failure for two patients and limited vascular access for the two others. Percutaneous cryoablation was proposed to patients as a last-resort therapeutic option with full disclosure of the potential associated risks. Between October 2011 and June 2012, four consecutive procedures were performed in four female patients in two institutions (Table). Patients’ ages ranged from 19–71 years (mean, 42.5 y). Two patients had a long history of venous malformations previously treated with surgery and two sclerotherapies with absolute alcohol under general anesthesia for one patient and two surgical interventions for the other. The last specific treatment was carried out a mean of 29 months (range, 6–52 mo) before cryoablation. Mean venous malformation volume was 49.6 cm3 (range, 21.7– 78.6 cm3). Venous malformations were painful for all patients (visual analog scale; mean, 5; range, 3–7). On ultrasound (US) examination, well-circumscribed but heterogeneous, hyperechogenic masses were described with low flow on Doppler. In addition to systematic US and Doppler
97% 95%
89% No 6
6 6.5
None
None
No
96% 98% 7 7 None None
No No
Follow-up (mo)
2
4 2.5 2 Surgeries
21.7 Surgery and 2 sclerotherapies
Lumbar Female 4 Mean
43 42.5
Female 3
16
Right limb
78.6 49.6
2 2 43.7 54.3 None None Left pectoral Right calf Female Female 1 2
37 71
Previous Treatments Gender
Age (y)
Cornelis et al
’
JVIR
imaging, a magnetic resonance (MR) imaging examination with contrast agent injection (MAGNETOM Aera 1.5 Tesla; Siemens, Erlangen, Germany) was performed for all patients. MR imaging examinations with or without fat saturation showed heterogeneous masses as a hyperintense signal on T2-weighted sequences and as a hypointense signal before contrast agent injection and hyperintense signal after contrast on T1-weighted sequences. A pathologic analysis was performed for all patients (two after surgical resection and two after percutaneous biopsy), and diagnosis of venous malformations was obtained for all patients. Inflammatory fibrovascular and adipose tissue was observed without tumoral cells but with numerous vascular vessels on gross pathology in all patients. Immunohistochemistry for HMGA2, CDK4, and MDM2 was negative and excluded aggressive soft tissue tumors, although CD31 and ERG were positive in all patients, which confirmed the diagnosis of venous malformation.
Procedure
Site
Initial Volume (cm3)
No. Cryoprobes
Complications
Recurrence of Symptoms
Decrease of Volume at 6 mo
Cryoablation of Venous Malformations
Patient
’
Table . Baseline Characteristics and Outcomes of Treated Patients
824
A single session of cryoablation was performed for each patient under US and computed tomography (CT) guidance and general anesthesia (Fig 1a–f). Two percutaneous cryoprobes (IceRod; Galil Medical, Yokneam, Israel) were used for three patients, and four cryoprobes were used for the last patient. The 17-gauge cryoprobes were introduced into the mass along the long axis, parallel to the skin to preserve it, under US guidance. Mean distance to the skin was 8.25 mm (range, 5–15 mm). A non–contrast-enhanced CT scan was used to assess the position of the cryoprobes before ablation and to obtain a baseline examination to avoid thermal injuries to adjacent tissues such as nerves during ice growth. To cover the entire lesion along the long axis, a first cycle of cryoablation was done with the cryoprobes fully inserted, then the probes were retracted by 4 cm or repositioned if necessary, and an optional second cycle was performed. No ice extension to the skin was observed during these two cycles (each involving 10 min freeze with argon gas, followed by 9 min passive and 1 min active thawing with helium gas, followed by 7 min freeze), assessed by real-time US monitoring. The ice covered the entire targeted lesion on the short axes visualized by CT scan performed at the end of each cryoablation cycle or after replacement. At the end of the cryoablation procedures, the probes were removed through active thawing.
Follow-up Follow-up examinations were performed at 1, 3, and 6 months for all patients, with clinical evaluation of pain. Imaging follow-up was performed with contrast-enhanced MR imaging at 3 and 6 months. All patient data were compiled and analyzed, and all images were retrospectively reviewed. The operator measured the tumor size by using the ellipsoid formula from the three greatest diameters on T2-weighted MR images (volume ¼ length depth width 0.5233). Procedural-related complications and side effects were noted and classified according to criteria
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Figure 1. Imaging of a recurrent venous malformation of the right calf in a 16-year-old girl before, during, and after cryoblation. (a) Initial direct opacification of the nidus before sclerosis of the venous malformation. (b) Imaging follow-up of the nidus with Doppler US showed recurrence of the venous malformation (arrowhead). (c) Axial T2-weighted MR image without fat saturation (arrow) showed a high signal venous malformation previously treated with two sessions of sclerotherapy. (d) Nonenhanced CT scan performed for cryoablation monitoring. Cryoprobes were inserted inside the tumor along the long axis under US guidance, but the final position was checked with a CT scan. Ice encompassed the entire lesion at the end of procedure. (e, f) Axial T2-weighted and enhanced T1-weighted MR images with fat saturation obtained 6 months after treatment. T2-weighted image showed no residual hyperintensity, and T1-weighted image showed only a slight enhancement (arrow) but no residual mass or muscle enlargement.
proposed by the Society of Interventional Radiology (SIR) (8). Data were entered into a worksheet for storage and extraction/analysis (Excel; Microsoft, Redmond, Washington). Statistical analysis on volume was performed with a Student t test, and P o .05 was considered significant.
RESULTS Procedure and Complications Procedure time was 50 minutes for all patients. All patients were discharged within 2 days (prednisone [Cortancyl;
826
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Cryoablation of Venous Malformations
Cornelis et al
’
JVIR
Figure 2. Imaging of a recurrent lumbar venous malformation in a 43-year-old woman before, during, and after cryoablation. (a) Enhanced axial T1-weighted MR image (arrow) showed the intramuscular venous malformation. (b) Axial enhanced T1-weighted MR image with fat saturation obtained 6 months after treatment showed only slight enhancement surrounding the ablative site and the asymptomatic residual mass (arrow).
Sanofi-Avantis, Paris, France]). All patients were discharged with prescriptions for short-term oral corticosteroid (prednisone [Cortancyl; Sanofi-Avantis, Paris, France]), 20–30 mg/d. All postoperative pain was low level (visual analog scale o 3), and all pain, along with soft tissue edema, disappeared progressively within 2 weeks after cryoablation in all patients. No severe complications were reported.
Efficacy Technical success was achieved in all patients in one cryoablation session. The clinical and imaging follow-up period ranged from 6–7 months (median, 6.5 mo). No pain was reported at 1 month. Palpation showed a progressive decrease of the mass volume, which was confirmed on MR imaging follow-up (Figs 1a–f, 2a–b). Mean venous malformation volume was 8.2 cm3 (range, 2.7–17.5 cm3) at 3 months and 1.2 cm3 (range, 0.5–1.8 cm3) at 6 months. The mean decrease in volume was 75% (range, 60%–90.5%) at 3 months (P ¼ .011) and 95% (range, 89.4%–98.2%) at 6 months (P ¼ .012) compared with before treatment. No residual enhancement was observed within the ablated areas at 6 months, but a thin peripheral enhancement persisted at 6 months for all patients. One patient showed a residual 8-mm hyperintense signal on T2-weighted images on the margins of the cryoablation area, probably corresponding to a residual nonablated tissue. Because the patient was asymptomatic, only clinical and radiologic follow-up evaluation was proposed.
DISCUSSION All patients treated for localized venous malformations with cryoablation reported a complete absence of pain 6 months after the procedure, and no severe complications or morbidity was observed. In terms of technical success, the venous malformations within the ablative zone had completely resolved on imaging follow-up at 6 months.
Cryoablation appears to be efficient for patients referred for local control of symptomatic venous malformation recurrences or as a last-resort treatment after discussion in a multidisciplinary committee. Complete coverage of the venous malformation by the ice is essential for technical success. To achieve this complete coverage, it was helpful to examine closely the multiplanar nonenhanced and contrast-enhanced MR and CT images, as proposed for desmoid tumors (3). We used real-time US monitoring, which is cheap and quick to set up and is useful for the placement of cryoprobes and growth monitoring. T2-weighted MR images are important to evaluate the extension of the malformation into adjacent structures because vascular malformations are usually clearly delineated (9). Gadolinium-enhanced T1-weighted imaging could also be useful in evaluating the circulatory portion of the malformation. Compared with sclerotherapy, which targets abnormal vessels, venous malformations and surrounding tissues are ablated concurrently with cryoablation. The mechanisms have been detailed by Walder (10), who studied the effects of freezing on large vessels. Risks of cryoablation compared with sclerotherapy are limited because preservation of the muscularis layer of vessels was observed, and there was no systemic effect of cryoablation. However, nerve or skin lesions could occur from direct thermal injuries of the ice if inadequate radiologic monitoring is carried out. Carbodissection with carbon dioxide can be performed easily (11) if critical structures are too close to the targeted lesion. For multiple venous malformations, cryoablation may also have a role because multiple sites could be treated either in one or multiple procedures, depending on their location and patient positioning, as proposed for desmoid tumors (4). Limitations of this study include its retrospective nature and the small number of patients. The small number of patients can be explained by the fact that these procedures were proposed as last-resort therapeutic options and performed on a case-by-case basis after discussion in a
Volume 24
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Number 6
’
June
’
2013
specific multidisciplinary team meeting because data about the role of cryoablation in soft tissue tumors are currently scarce. We treated only small localized venous malformations in the muscle or subcutaneous area. Cryotherapy may not be effective for large venous malformations that are infiltrative or have skin involvement. In conclusion, as proposed in this short-term small retrospective study, cryoablation may be a promising alternative treatment for symptomatic localized venous malformation in terms of morbidity and efficacy, as long as the malformation can be completely encompassed within the ablation zones. Nevertheless, long-term evaluation of a larger patient population is required to validate these findings.
ACKNOWLEDGMENT The authors thank Pippa McKelvie-Sebileau for medical editorial services.
REFERENCES 1. James CA, Braswell LE, Wright LB, et al. Preoperative sclerotherapy of facial venous malformations: impact on surgical parameters and longterm follow-up. J Vasc Interv Radiol 2011; 22:953–960.
827
2. Childs DD, Emory CL. Successful treatment of intramuscular venous malformation with image-guided radiofrequency ablation. J Vasc Interv Radiol 2012; 23:1391–1393. 3. Kujak JL, Liu PT, Johnson GB, Callstrom MR. Early experience with percutaneous cryoablation of extra-abdominal desmoid tumors. Skeletal Radiol 2010; 39:175–182. 4. Cornelis F, Italiano A, Al-Ammari S, et al. Successful iterative percutaneous cryoablation of multiple extraabdominal desmoid tumors in a patient with gardner syndrome. J Vasc Interv Radiol 2012; 23: 1101–1103. 5. Cornelis F, Neuville A, Labreze C, et al. Percutaneous cryotherapy of vascular malformation: initial experience. Cardiovasc Intervent Radiol 2012 Jun 22 [Epub ahead of print]. 6. Janzen NK, Perry KT, Han KR, et al. The effects of intentional cryoablation and radio frequency ablation of renal tissue involving the collecting system in a porcine model. J Urol 2005; 173:1368–1374. 7. Callstrom MR, Atwell TD, Charboneau JW, et al. Painful metastases involving bone: percutaneous image-guided cryoablation—prospective trial interim analysis. Radiology 2006; 241:572–580. 8. Goldberg SN, Grassi CJ, Cardella JF, et al. Image-guided tumor ablation: standardization of terminology and reporting criteria. J Vasc Interv Radiol 2005; 16:765–778. 9. Dubois J, Soulez G, Oliva VL, Berthiaume MJ, Lapierre C, Therasse E. Soft-tissue venous malformations in adult patients: imaging and therapeutic issues. Radiographics 2001; 21:1519–1531. 10. Walder HA. Application of cryotherapy in cerebrovascular anomalies: an experimental and clinical study. J Neurol Neurosurg Psychiatry 1971; 34: 105. 11. Buy X, Tok CH, Szwarc D, Bierry G, Gangi A. Thermal protection during percutaneous thermal ablation procedures: interest of carbon dioxide dissection and temperature monitoring. Cardiovasc Intervent Radiol 2009; 32:529–534.
Percutaneous Cryoablation of Symptomatic Localized Venous Malformations: Preliminary Short-term Results Franc- ois Cornelis, MD, Marion Havez, MD, Christine Labreze, MD, Alain Taieb, MD, Binh N. Bui, MD, Dominique Midy, MD, and Nicolas Grenier, MD
ABSTRACT Short-term outcomes after percutaneous image-guided cryoablation of symptomatic venous malformations in four consecutive patients (mean age, 42.5 y) are reported. Two patients had local recurrences after previous treatment. Mean preoperative pain was estimated on a visual analog scale at 5 (range, 3–7). Cryoablation was performed in a single session under general anesthesia. Postoperative pain and superficial edema disappeared within 2 weeks. No pain was subsequently reported, and magnetic resonance imaging demonstrated a significant volume decrease at 3 months (75%; P ¼ .01) and at 6 months (95%; P ¼ .01). Percutaneous cryoablation shows promising local control in patients with symptomatic venous malformations.
Image-guided sclerotherapy and surgical resection are recognized as standard therapeutic options for venous malformations (1). However, therapeutic alternatives are being developed for recurrence after sclerotherapy or for vascular anomalies with mainly solid components such as fibroadipose vascular anomalies, which could be inaccessible by sclerotherapy. Childs and Emory (2) reported more recently the successful treatment of intramuscular venous malformation with image-guided radiofrequency ablation. Owing to its minimally invasive nature and as proposed for desmoid tumors occurring in soft tissue (3,4), cryoablation may also provide a promising alternative option for relieving symptoms of venous malformations affecting patients’ quality of life (5) because it causes less damage to surrounding tissues than surgery or radiofrequency ablation (6). Postoperative pain is mild and recovery is rapid after the procedure, which can be performed under local or general anesthesia (7). The purpose of this preliminary study was to report the short-term local control
From the Departments of Radiology (F.C., M.H., N.G.), Pediatric Dermatology (C.L.), Dermatology (A.T.), and Vascular Surgery (D.M.), Pellegrin Hospital, Place Ame´lie Raba Le´on, 33076 Bordeaux, France; and Departments of Radiology (F.C.) and Oncology (B.N.B.), Institut Bergonie´, Bordeaux, France. Received January 22, 2013; final revision received and accepted March 4, 2013. Address correspondence to F.C.; E-mail: francois.cornelis@ chu-bordeaux.fr None of the authors have identified a conflict of interest. & SIR, 2013 J Vasc Interv Radiol 2013; 24:823–827 http://dx.doi.org/10.1016/j.jvir.2013.03.005
after percutaneous image-guided cryoablation of localized symptomatic venous malformations.
MATERIALS AND METHODS Patients and Lesions The institutional review board approved this retrospective study. After discussion in a multidisciplinary team meeting involving dermatologists, surgeons, and radiologists, surgery was rejected for all four patients because of coexisting or expected major morbidity. Sclerotherapy was also rejected because of previous treatment failure for two patients and limited vascular access for the two others. Percutaneous cryoablation was proposed to patients as a last-resort therapeutic option with full disclosure of the potential associated risks. Between October 2011 and June 2012, four consecutive procedures were performed in four female patients in two institutions (Table). Patients’ ages ranged from 19–71 years (mean, 42.5 y). Two patients had a long history of venous malformations previously treated with surgery and two sclerotherapies with absolute alcohol under general anesthesia for one patient and two surgical interventions for the other. The last specific treatment was carried out a mean of 29 months (range, 6–52 mo) before cryoablation. Mean venous malformation volume was 49.6 cm3 (range, 21.7– 78.6 cm3). Venous malformations were painful for all patients (visual analog scale; mean, 5; range, 3–7). On ultrasound (US) examination, well-circumscribed but heterogeneous, hyperechogenic masses were described with low flow on Doppler. In addition to systematic US and Doppler
97% 95%
89% No 6
6 6.5
None
None
No
96% 98% 7 7 None None
No No
Follow-up (mo)
2
4 2.5 2 Surgeries
21.7 Surgery and 2 sclerotherapies
Lumbar Female 4 Mean
43 42.5
Female 3
16
Right limb
78.6 49.6
2 2 43.7 54.3 None None Left pectoral Right calf Female Female 1 2
37 71
Previous Treatments Gender
Age (y)
Cornelis et al
’
JVIR
imaging, a magnetic resonance (MR) imaging examination with contrast agent injection (MAGNETOM Aera 1.5 Tesla; Siemens, Erlangen, Germany) was performed for all patients. MR imaging examinations with or without fat saturation showed heterogeneous masses as a hyperintense signal on T2-weighted sequences and as a hypointense signal before contrast agent injection and hyperintense signal after contrast on T1-weighted sequences. A pathologic analysis was performed for all patients (two after surgical resection and two after percutaneous biopsy), and diagnosis of venous malformations was obtained for all patients. Inflammatory fibrovascular and adipose tissue was observed without tumoral cells but with numerous vascular vessels on gross pathology in all patients. Immunohistochemistry for HMGA2, CDK4, and MDM2 was negative and excluded aggressive soft tissue tumors, although CD31 and ERG were positive in all patients, which confirmed the diagnosis of venous malformation.
Procedure
Site
Initial Volume (cm3)
No. Cryoprobes
Complications
Recurrence of Symptoms
Decrease of Volume at 6 mo
Cryoablation of Venous Malformations
Patient
’
Table . Baseline Characteristics and Outcomes of Treated Patients
824
A single session of cryoablation was performed for each patient under US and computed tomography (CT) guidance and general anesthesia (Fig 1a–f). Two percutaneous cryoprobes (IceRod; Galil Medical, Yokneam, Israel) were used for three patients, and four cryoprobes were used for the last patient. The 17-gauge cryoprobes were introduced into the mass along the long axis, parallel to the skin to preserve it, under US guidance. Mean distance to the skin was 8.25 mm (range, 5–15 mm). A non–contrast-enhanced CT scan was used to assess the position of the cryoprobes before ablation and to obtain a baseline examination to avoid thermal injuries to adjacent tissues such as nerves during ice growth. To cover the entire lesion along the long axis, a first cycle of cryoablation was done with the cryoprobes fully inserted, then the probes were retracted by 4 cm or repositioned if necessary, and an optional second cycle was performed. No ice extension to the skin was observed during these two cycles (each involving 10 min freeze with argon gas, followed by 9 min passive and 1 min active thawing with helium gas, followed by 7 min freeze), assessed by real-time US monitoring. The ice covered the entire targeted lesion on the short axes visualized by CT scan performed at the end of each cryoablation cycle or after replacement. At the end of the cryoablation procedures, the probes were removed through active thawing.
Follow-up Follow-up examinations were performed at 1, 3, and 6 months for all patients, with clinical evaluation of pain. Imaging follow-up was performed with contrast-enhanced MR imaging at 3 and 6 months. All patient data were compiled and analyzed, and all images were retrospectively reviewed. The operator measured the tumor size by using the ellipsoid formula from the three greatest diameters on T2-weighted MR images (volume ¼ length depth width 0.5233). Procedural-related complications and side effects were noted and classified according to criteria
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’
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Figure 1. Imaging of a recurrent venous malformation of the right calf in a 16-year-old girl before, during, and after cryoblation. (a) Initial direct opacification of the nidus before sclerosis of the venous malformation. (b) Imaging follow-up of the nidus with Doppler US showed recurrence of the venous malformation (arrowhead). (c) Axial T2-weighted MR image without fat saturation (arrow) showed a high signal venous malformation previously treated with two sessions of sclerotherapy. (d) Nonenhanced CT scan performed for cryoablation monitoring. Cryoprobes were inserted inside the tumor along the long axis under US guidance, but the final position was checked with a CT scan. Ice encompassed the entire lesion at the end of procedure. (e, f) Axial T2-weighted and enhanced T1-weighted MR images with fat saturation obtained 6 months after treatment. T2-weighted image showed no residual hyperintensity, and T1-weighted image showed only a slight enhancement (arrow) but no residual mass or muscle enlargement.
proposed by the Society of Interventional Radiology (SIR) (8). Data were entered into a worksheet for storage and extraction/analysis (Excel; Microsoft, Redmond, Washington). Statistical analysis on volume was performed with a Student t test, and P o .05 was considered significant.
RESULTS Procedure and Complications Procedure time was 50 minutes for all patients. All patients were discharged within 2 days (prednisone [Cortancyl;
826
’
Cryoablation of Venous Malformations
Cornelis et al
’
JVIR
Figure 2. Imaging of a recurrent lumbar venous malformation in a 43-year-old woman before, during, and after cryoablation. (a) Enhanced axial T1-weighted MR image (arrow) showed the intramuscular venous malformation. (b) Axial enhanced T1-weighted MR image with fat saturation obtained 6 months after treatment showed only slight enhancement surrounding the ablative site and the asymptomatic residual mass (arrow).
Sanofi-Avantis, Paris, France]). All patients were discharged with prescriptions for short-term oral corticosteroid (prednisone [Cortancyl; Sanofi-Avantis, Paris, France]), 20–30 mg/d. All postoperative pain was low level (visual analog scale o 3), and all pain, along with soft tissue edema, disappeared progressively within 2 weeks after cryoablation in all patients. No severe complications were reported.
Efficacy Technical success was achieved in all patients in one cryoablation session. The clinical and imaging follow-up period ranged from 6–7 months (median, 6.5 mo). No pain was reported at 1 month. Palpation showed a progressive decrease of the mass volume, which was confirmed on MR imaging follow-up (Figs 1a–f, 2a–b). Mean venous malformation volume was 8.2 cm3 (range, 2.7–17.5 cm3) at 3 months and 1.2 cm3 (range, 0.5–1.8 cm3) at 6 months. The mean decrease in volume was 75% (range, 60%–90.5%) at 3 months (P ¼ .011) and 95% (range, 89.4%–98.2%) at 6 months (P ¼ .012) compared with before treatment. No residual enhancement was observed within the ablated areas at 6 months, but a thin peripheral enhancement persisted at 6 months for all patients. One patient showed a residual 8-mm hyperintense signal on T2-weighted images on the margins of the cryoablation area, probably corresponding to a residual nonablated tissue. Because the patient was asymptomatic, only clinical and radiologic follow-up evaluation was proposed.
DISCUSSION All patients treated for localized venous malformations with cryoablation reported a complete absence of pain 6 months after the procedure, and no severe complications or morbidity was observed. In terms of technical success, the venous malformations within the ablative zone had completely resolved on imaging follow-up at 6 months.
Cryoablation appears to be efficient for patients referred for local control of symptomatic venous malformation recurrences or as a last-resort treatment after discussion in a multidisciplinary committee. Complete coverage of the venous malformation by the ice is essential for technical success. To achieve this complete coverage, it was helpful to examine closely the multiplanar nonenhanced and contrast-enhanced MR and CT images, as proposed for desmoid tumors (3). We used real-time US monitoring, which is cheap and quick to set up and is useful for the placement of cryoprobes and growth monitoring. T2-weighted MR images are important to evaluate the extension of the malformation into adjacent structures because vascular malformations are usually clearly delineated (9). Gadolinium-enhanced T1-weighted imaging could also be useful in evaluating the circulatory portion of the malformation. Compared with sclerotherapy, which targets abnormal vessels, venous malformations and surrounding tissues are ablated concurrently with cryoablation. The mechanisms have been detailed by Walder (10), who studied the effects of freezing on large vessels. Risks of cryoablation compared with sclerotherapy are limited because preservation of the muscularis layer of vessels was observed, and there was no systemic effect of cryoablation. However, nerve or skin lesions could occur from direct thermal injuries of the ice if inadequate radiologic monitoring is carried out. Carbodissection with carbon dioxide can be performed easily (11) if critical structures are too close to the targeted lesion. For multiple venous malformations, cryoablation may also have a role because multiple sites could be treated either in one or multiple procedures, depending on their location and patient positioning, as proposed for desmoid tumors (4). Limitations of this study include its retrospective nature and the small number of patients. The small number of patients can be explained by the fact that these procedures were proposed as last-resort therapeutic options and performed on a case-by-case basis after discussion in a
Volume 24
’
Number 6
’
June
’
2013
specific multidisciplinary team meeting because data about the role of cryoablation in soft tissue tumors are currently scarce. We treated only small localized venous malformations in the muscle or subcutaneous area. Cryotherapy may not be effective for large venous malformations that are infiltrative or have skin involvement. In conclusion, as proposed in this short-term small retrospective study, cryoablation may be a promising alternative treatment for symptomatic localized venous malformation in terms of morbidity and efficacy, as long as the malformation can be completely encompassed within the ablation zones. Nevertheless, long-term evaluation of a larger patient population is required to validate these findings.
ACKNOWLEDGMENT The authors thank Pippa McKelvie-Sebileau for medical editorial services.
REFERENCES 1. James CA, Braswell LE, Wright LB, et al. Preoperative sclerotherapy of facial venous malformations: impact on surgical parameters and longterm follow-up. J Vasc Interv Radiol 2011; 22:953–960.
827
2. Childs DD, Emory CL. Successful treatment of intramuscular venous malformation with image-guided radiofrequency ablation. J Vasc Interv Radiol 2012; 23:1391–1393. 3. Kujak JL, Liu PT, Johnson GB, Callstrom MR. Early experience with percutaneous cryoablation of extra-abdominal desmoid tumors. Skeletal Radiol 2010; 39:175–182. 4. Cornelis F, Italiano A, Al-Ammari S, et al. Successful iterative percutaneous cryoablation of multiple extraabdominal desmoid tumors in a patient with gardner syndrome. J Vasc Interv Radiol 2012; 23: 1101–1103. 5. Cornelis F, Neuville A, Labreze C, et al. Percutaneous cryotherapy of vascular malformation: initial experience. Cardiovasc Intervent Radiol 2012 Jun 22 [Epub ahead of print]. 6. Janzen NK, Perry KT, Han KR, et al. The effects of intentional cryoablation and radio frequency ablation of renal tissue involving the collecting system in a porcine model. J Urol 2005; 173:1368–1374. 7. Callstrom MR, Atwell TD, Charboneau JW, et al. Painful metastases involving bone: percutaneous image-guided cryoablation—prospective trial interim analysis. Radiology 2006; 241:572–580. 8. Goldberg SN, Grassi CJ, Cardella JF, et al. Image-guided tumor ablation: standardization of terminology and reporting criteria. J Vasc Interv Radiol 2005; 16:765–778. 9. Dubois J, Soulez G, Oliva VL, Berthiaume MJ, Lapierre C, Therasse E. Soft-tissue venous malformations in adult patients: imaging and therapeutic issues. Radiographics 2001; 21:1519–1531. 10. Walder HA. Application of cryotherapy in cerebrovascular anomalies: an experimental and clinical study. J Neurol Neurosurg Psychiatry 1971; 34: 105. 11. Buy X, Tok CH, Szwarc D, Bierry G, Gangi A. Thermal protection during percutaneous thermal ablation procedures: interest of carbon dioxide dissection and temperature monitoring. Cardiovasc Intervent Radiol 2009; 32:529–534.