Julien Garnon

Percutaneous thermal ablation: how to protect the surrounding organs.

A variety of thermal ablation techniques have been advocated for percutaneous tumor management. Although the above techniques are considered safe, they can be complicated with unintended thermal injury to the surrounding structures, with disastrous results. In the present article we report a number of different insulation techniques (hydrodissection, gas dissection and balloon interposition, warming/cooling systems) that can be applied. Emphasis is given to the procedure-related details, and we present the advantages and drawbacks of the insulation techniques. We also provide tips on avoiding painful skin burns when treating superficial lesions. Finally, we point out the interest of temperature monitoring and how it can be achieved (use of thermocouples, fiberoptic thermosensors, or direct magnetic resonance imaging temperature mapping). The above thermal insulation and temperature monitoring techniques can be applied alone or in combination. Familiarity with these techniques is essential to avoid major complications and to increase the indications of thermal ablation procedures.

Percutaneous Renal Cryoablation: Prospective Experience Treating 120 Consecutive Tumors

OBJECTIVE The purpose of this study was to evaluate the safety and efficacy of percutaneous renal cryoablation. SUBJECTS AND METHODS A prospective nonrandomized evaluation of 120 renal tumors in 95 patients treated with percutaneous cryoablation because their condition did not allow surgery focused on tumor characteristics, complications, hospital course, treatment success based on MRI follow-up, and effect on renal function. RESULTS The mean follow-up period was 28 months (range, 6-63 months). The mean tumor size was 26 mm (range, 10-68 mm), including 20 tumors larger than 40 mm. Ninety-one tumors were treated with CT and 29 with MRI guidance. Fifty-six tumors were anterior, and thermal protection of adjacent organs with carbodissection or hydrodissection was used in 55 cases. According to the Clavien-Dindo classification, five grade II complications and four grade III-V complications occurred. The technical success rate was 94%. Two tumors required a second session of cryoablation because of recurrence or residual tumor. Twelve months after treatment the overall survival was 96.7%, and the disease-free survival rate was 96.4%, including patients with recurrent genetic tumors. Renal function remained unchanged even in the subgroup of patients with a single kidney. CONCLUSION Midterm follow-up shows that percutaneous renal cryoablation is an effective and safe alternative technique for patients whose condition does not allow surgery and that renal function is preserved. Cryoablation combined with percutaneous thermal protection techniques allows treatment of more complex tumors (large central tumors and tumors close to vulnerable structures). However, T1b and central tumors are associated with higher risk of incomplete treatment.

Interest of Electrostimulation of Peripheral Motor Nerves during Percutaneous Thermal Ablation

PurposeWe present our experience of utilizing peripheral nerve electrostimulation as a complementary monitoring technique during percutaneous thermal ablation procedures; and we highlight its utility and feasibility in the prevention of iatrogenic neurologic thermal injury.MethodsPeripheral motor nerve electrostimulation was performed in 12 patients undergoing percutaneous image-guided thermal ablations of spinal/pelvic lesions in close proximity to the spinal cord and nerve roots. Electrostimulation was used in addition to existing insulation (active warming/cooling with hydrodissection, passive insulation with CO2 insufflation) and temperature monitoring (thermocouples) techniques. Impending neurologic deficit was defined as a visual reduction of muscle response or need for a stronger electric current to evoke muscle contraction, compared with baseline.ResultsSignificant reduction of the muscle response to electrostimulation was observed in three patients during the ablation, necessitating temporary interruption, followed by injection of warm/cool saline. This resulted in complete recovery of the muscle response in two cases, while for the third patient the response did not improve and the procedure was terminated. No patient experienced postoperative motor deficit.ConclusionPeripheral motor nerve electrostimulation is a simple, easily accessible technique allowing early detection of impending neurologic injury during percutaneous image-guided thermal ablation. It complements existing monitoring techniques and provides a functional assessment along the whole length of the nerve.

CIRSE Guidelines on Percutaneous Vertebral Augmentation

Vertebral compression fracture (VCF) is an important cause of severe debilitating back pain, adversely affecting quality of life, physical function, psychosocial performance, mental health and survival. Different vertebral augmentation procedures (VAPs) are used in order to consolidate the VCFs, relief pain,and whenever posible achieve vertebral body height restoration. In the present review we give the indications, contraindications, safety profile and outcomes of the existing percutaneous VAPs.

Percutaneous image-guided cryoablation: current applications and results in the oncologic field

Percutaneous imaging-guided cryoablation (PICA) is a recently developed technique, which applies extreme hypothermia to destroy tumours under close imaging surveillance. It is minimally invasive, safe, repeatable, and does not interrupt or compromise other oncologic therapies. It presents several advantages over more established heat-based thermal ablation techniques (e.g. radiofrequency ablation; RFA) including intrinsic analgesic properties, superior monitoring capability on multi-modal imaging, ability to treat larger tumours, and preservation of tissue collagenous architecture. There has been a recent large increase in reports evaluating the utility of PICA in a wide range of patients and tumours, but systematic analysis of the literature is challenging due to the rapid pace of change and predominance of extensively heterogeneous level III studies. The precise onco-therapeutic role of PICA has not been established. This narrative review outlines the available evidence for PICA in a range of tumours. Current indications include curative therapy of small T1a renal tumours; curative/palliative therapy of small primary/secondary lung tumours where RFA is unsuitable; palliation of painful bone metastases; and urologic treatment of organ-confined prostate cancer. There is growing evidence to support its use for small hepatic tumours, and encouraging results have been obtained for breast tumours, extra-abdominal desmoid tumours, and management of higher-stage tumours and oligometastatic disease. However, the overall evidence base is weak, effectively restricting PICA to cases where standard therapy and RFA are unsuitable. As the technique and evidence continue to mature, the benefits of this emerging technique will hopefully become more widely available to cancer patients in the future.

Image-Guided Spinal Ablation: A Review

The image-guided thermal ablation procedures can be used to treat a variety of benign and malignant spinal tumours. Small size osteoid osteoma can be treated with laser or radiofrequency. Larger tumours (osteoblastoma, aneurysmal bone cyst and metastasis) can be addressed with radiofrequency or cryoablation. Results on the literature of spinal microwave ablation are scarce, and thus it should be used with caution. A distinct advantage of cryoablation is the ability to monitor the ice-ball by intermittent CT or MRI. The different thermal insulation, temperature and electrophysiological monitoring techniques should be applied. Cautious pre-procedural planning and intermittent intra-procedural monitoring of the ablation zone can help reduce neural complications. Tumour histology, patient clinical-functional status and life-expectancy should define the most efficient and least disabling treatment option.

Percutaneous Image-guided Laser Photocoagulation of Spinal Osteoid Osteoma: A Single-Institution Series

PURPOSE To retrospectively evaluate the safety and efficacy of percutaneous image-guided laser photocoagulation for the treatment of spinal osteoid osteoma (OO) in proximity to neural structures. MATERIALS AND METHODS This study was institutional review board-approved with waivers of informed consent. From January 1994 until October 2014, 58 patients with spinal OO (mean age, 25 years; 40 men, 17 women) were treated in one institution by using laser photocoagulation with combined computed tomographic (CT) and fluoroscopic guidance. One patient was excluded because of less than 3 months of follow-up. All patients had typical clinical and imaging findings. Clinical features, radiologic data, and procedure-related data were reviewed, and limitations, complications, and failure rate were evaluated. All data were expressed as means ± standard deviation. P values of less than .05 were indicative of statistical significance. RESULTS OO was in the vertebral body for 18 of 57 patients, the neural arch for 21 of 57 patients, and the articular process for 18 of 57 patients. Mean nidal diameter was 8 mm, and the mean distance from the closest neural structure was 6.6 mm (minimum distance, ≤5 mm in 35 of 57 patients). In 35 of 57 patients, no cortical coverage was present between the nidus and neural structure in danger. Mean total energy delivered was 1271 J (2-watt continuous power mode). Thermal insulation (carbon dioxide and/or hydrodissection), temperature monitoring, and electrostimulation were used in 42, 24, and one patient, respectively. Primary clinical success at 1 month was 98.2%. Total recurrence rate was 5.3%. All recurrences were addressed percutaneously. Secondary success rate was 100%. One-year follow-up is available in 54 of 57 patients. No major complications were noted. CONCLUSION Spinal OO can be safely and effectively treated with percutaneous laser photocoagulation. In cases that are less than 8 mm to 10 mm distance and in the absence of cortical coverage, thermal protection techniques of the neural structures should be used.

Percutaneous Techniques for Cervical Pain of Discal Origin

Cervical discogenic pain is an important cause of suffering and disability in the adult population. Pain management in cervical disc herniation relies initially on conservative care (rest, physiotherapy, and oral medications). Once conservative treatment has failed, different percutaneous minimally invasive radiological procedures can be applied to relief pain. This article offers a systematic review on the percutaneous minimally invasive techniques that can be advocated for the treatment of cervical pain of discal origin. Periradicular steroid injection under image guidance (computed tomography or magnetic resonance imaging) is the first technique to be considered. The steroid injection aims at reducing the periradicular inflammation and thus relieves the radicular pain. The steroid injections present satisfying short-term results, but pain can recur in the long term. Whenever the steroid injections fail to relieve pain from a contained cervical disc herniation, the more invasive percutaneous disc decompression techniques should be proposed. Percutaneous radiofrequency nucleoplasty is the most often applied technique on the cervical level with a low risk of thermal damage. When the indications and instructions are respected, radiofrequency nucleoplasty presents accepted safety and efficacy levels.

Treatment of a spinal aneurysmal bone cyst using combined image-guided cryoablation and cementoplasty

The authors describe the case of a 6.6-cm symptomatic spinal aneurysmal bone cyst (ABC) in a 17-year-old athlete treated percutaneously. Surgical treatment was not considered as the first option owing to its invasiveness and associated morbidity. CT-guided cryoablation of the expansile part of the ABC was performed for tumour shrinkage and nerve decompression. Thermal insulation, temperature monitoring and functional control/electrostimulation of the neural structures at risk were applied. Finally, the bony defect was cemented. No complications occurred during the procedure. Complete resolution of the ABC on imaging and clinical improvement were achieved. Percutaneous cryoablation should be considered as an alternative treatment option, especially when tumour size reduction is desired.

Imaging-Guided Percutaneous Cryotherapy of Bone and Soft-Tissue Tumors: What Is the Impact on the Muscles Around the Ablation Site?

OBJECTIVE The objectives of our study were to evaluate the incidence of muscular injury after cryoablation of bone and soft-tissue tumors, to relate MRI findings to the size of the intramuscular ice ball, and to determine the clinical significance of postcryotherapy myositis. MATERIALS AND METHODS Between January 2010 and October 2012, 24 bone and soft-tissue lesions (16 pelvic lesions, three shoulder lesions, and five paravertebral lesions) in 21 patients treated by imaging-guided percutaneous cryoablation and followed up with MRI were retrospectively analyzed. Muscular hyperintensity on T2 STIR images was graded as follows: grade 0, no myositis; grade 1, local myositis; grade 2, myositis in less than half of the volume of the muscle; or grade 3, myositis in half of the volume of the muscle or more. The presence of T2 STIR hyperintensity in the muscles surrounding the cryoablation site was correlated with the volume of the intramuscular ice ball. RESULTS Muscular T2 STIR hyperintensity was observed in 87.5% of cases (grade 0 in 12.5%, grade 1 in 45.8%, grade 2 in 20.8%, and grade 3 in 20.8%). The volume of the intramuscular ice ball and grade of myositis (mean volume: grade 0, 2.8 cm(3); grade 1, 9.2 cm(3); grade 2, 17.1 cm(3); grade 3, 42.9 cm(3)) were positively correlated in the 24 lesions in the study cohort (r = 0.64, p < 0.001). Only two cases of myositis (grade 3) were symptomatic, and antiinflammatory drugs promoted pain resolution in both cases. CONCLUSION Muscular injury around the cryoablation site is commonly observed and is correlated with the volume of the ice ball. When muscular injury around the cryoablation site causes pain, the symptoms differ from the initial tumoral pain and can be treated with antiinflammatory drugs.