Karin Steinke

Radiologic appearance and complications of percutaneous computed tomography-guided radiofrequency-ablated pulmonary metastases from colorectal carcinoma.

Objectives To describe the morphologic appearance over time of percutaneously radiofrequency-ablated pulmonary metastases from colorectal cancer and to focus on the occurrence of the most common complications. Methods Twenty patients have been treated with computed tomography (CT)–guided radiofrequency ablation (RFA) for 41 pulmonary metastases using the expandable 14-gauge StarBurst XL RF electrode along with the 1500 generator (RITA Medical Systems, Mountain View, CA). The average number of lesions per patient was 2.05, ranging from 1 to 4 lesions. Results The typical feature of the radiofrequency-ablated site immediately after the procedure was a light bulb–shaped opacification surrounding the probe. This became a more spherically shaped feature over time and steadily decreased in size. At 3 months after RFA, the lesion was approximately the same size as at baseline. The lesion subsequently shrank within the following 3 months, usually with a small scar remaining. Pneumothorax occurred in 50% of the patients, and a chest tube was required in 50% of the patients affected. Cavitation occurred in 24% of the lesions. Intraparenchymal hemorrhage was observed in 7.5% of the cases. Conclusions Image-guided pulmonary RFA is a safe minimally invasive therapy modality with acceptable morbidity. Ablated lesion size usually exceeds the dimensions of the initial tumor for the first 3 months after ablation and continuously shrinks thereafter.

Percutaneous imaging-guided radiofrequency ablation in patients with colorectal pulmonary metastases: 1-year follow-up.

AbstractBackground: We assessed the safety and evidence of efficacy of radiofrequency ablation (RFA) for colorectal lung metastases with follow-up to 1 year. Methods: Twenty-three patients had percutaneous RFA for 52 colorectal pulmonary metastases under fluoro-computed tomography (CT). Patients received intravenous conscious sedation and local analgesia with routine hospitalization and monitoring for 24 hours after RFA. Patients had CT scanning at 1 month and then every 3 months, with serum carcinoembryonic antigen assessment monthly and every 3 months. Results: All ablations were technically successful. Tumor diameter ranged from .3 to 4.2 cm. Pneumothorax occurred in 43% (10 of 23) of patients. Six patients required intercostal chest drain placement. Six patients had a second RFA, four for new lesions and two for re-treatment of a previously treated lesion. The median admission was 2.0 days (range, 1–9 days). The median follow-up was 428 days (range, 173–829 days); data are reported to 1 year in this article. Five patients died at 5, 6, 8, 8, and 12 months after RFA from extrapulmonary (n = 1) or widespread (n = 4) disease. One patient developed a malignant pleural effusion at 6 months after RFA. Cavitation was seen in nine treated lesions (17%); all resolved with scar tissue contraction by 12 months. Eighteen patients with CT scan follow-up at 1 year have 40 lesions classified as disappeared (n = 17), decreased (n = 5), stable/same size (n = 4), or increased (n = 14). Conclusions: Percutaneous imaging–guided RFA of multiple colorectal pulmonary metastases is a minimally invasive treatment option with modest morbidity. A significant proportion of patients show good evidence of successful local control at 1 year.

Percutaneous radiofrequency ablation of pulmonary metastases in patients with colorectal cancer

This study aimed to assess the safety and efficacy of imaging‐guided percutaneous radiofrequency ablation (RFA) for local control of lung metastases from colorectal cancer (CRC).

Treatment Failure After Percutaneous Radiofrequency Ablation for Nonsurgical Candidates With Pulmonary Metastases From Colorectal Carcinoma

BackgroundThis study critically evaluated the local and overall treatment failure rates after percutaneous radiofrequency ablation (RFA) of pulmonary metastases from colorectal carcinoma.MethodsFifty-five nonsurgical candidates underwent RFA of colorectal pulmonary metastases. The primary end points of this study were local progression-free survival (PFS) and overall PFS. Univariate and multivariate analyses were performed to identify significant prognostic parameters for local and overall PFS.ResultsThe local recurrence rate was 38%. For local PFS, univariate analysis demonstrated that the largest size of lung metastasis, the location of lung metastases, the post-RFA carcinoembryonic antigen level at 1 month, and the post-RFA carcinoembryonic antigen level at 3 months were significant prognostic indicators. In multivariate analysis, a largest size of lung metastasis of >3 cm and a post-RFA carcinoembryonic antigen level of >5 ng/mL at 1 month were independently associated with a reduced local PFS. The overall recurrence rate was 66%. For overall PFS, univariate analysis demonstrated that sex and the largest size of lung metastasis were significant prognostic indicators. In multivariate analysis, a largest size of lung metastasis of >3 cm was independently associated with a reduced overall PFS.ConclusionsRFA of colorectal pulmonary metastases may have a useful role in local disease control for nonsurgical candidates, but its efficacy in patients with a lung metastasis of >3 cm is limited.

CT-Guided Radiofrequency Ablation of a Pulmonary Metastasis Followed by Surgical Resection

Outpatient CT-guided radiofrequency ablation (RFA) of a pulmonary metastasis followed by surgical resection and histopathological analysis was performed in a 72-year-old lady suffering from a peritoneal leiomyosarcoma. Histological workup 3 weeks post-ablation showed complete devitalization of the metastasis. This case report demonstrates that complete thermal destruction of a pulmonary metastasis by percutaneous image-guided RFA is possible.

Learning curve for percutaneous radiofrequency ablation of pulmonary metastases from colorectal carcinoma: a prospective study of 70 consecutive cases.

BackgroundPercutaneous radiofrequency ablation (RFA) for inoperable colorectal pulmonary metastases is associated with a morbidity rate of 30% to 40%. A learning curve in this treatment approach has not been documented before.MethodsThe clinical and treatment-related data regarding 70 consecutive percutaneous RFA procedures for inoperable colorectal pulmonary metastases were collected prospectively. A comparison between the initial 35 cases (group 1) and the subsequent 35 cases (group 2) was performed. Univariate and multivariate analyses were conducted to identify the significant risk factors for overall morbidity, pneumothorax, and chest drain requirement.ResultsThere was no hospital mortality. The overall morbidity rate was 37%. The rate of pneumothorax was 27%. Twelve patients (17%) required chest drain insertion for pneumothorax. There was a significant decline in the incidence of overall morbidity, pneumothorax, and chest drain requirement in group 2 as compared with group 1. Both the number of lung metastases ablated and the RFA treatment period (group 1 vs. group 2) were independent risk factors for overall morbidity, pneumothorax, and chest drain requirement. Distribution of lung metastases (unilateral vs. bilateral) was an independent risk factor for overall morbidity and pneumothorax, but not for chest drain requirement.ConclusionsThere is a learning curve for percutaneous lung RFA. With accumulated experience in this procedure, a low morbidity rate can be achieved.

Pulmonary hemorrhage during percutaneous radiofrequency ablation: a more frequent complication than assumed?

OBJECTIVE To alert clinicians of the underreported complication of intraparenchymal lung hemorrhage during percutaneous radiofrequency ablation (RFA) of primary and secondary pulmonary malignancies. METHODS Of 101 RF ablations performed in 46 patients, 81 were retrospectively assessed for periprocedural intrapulmonary bleeding. The data was compared with the literature for this minimally invasive interventional treatment as well as with the reported frequency of lung hemorrhage during diagnostic lung biopsies. RESULTS Our incidence of hemorrhage during percutaneous lung RFA was 5.9%. The reported frequency in the scarce literature available is less than 1%. Data in the literature for percutaneous biopsy-related intraparenchymal hemorrhage ranges from 1.4% for fine-needle aspirations to 29% for core biopsies. CONCLUSION Intraparenchymal lung hemorrhage during percutaneous RFA of primary and secondary pulmonary malignancies is similar to reported lung hemorrhage for diagnostic core biopsies. We believe this complication to be underreported in the literature.

Percutaneous Radiofrequency Ablation of Lung Tumors: Difficulty Withdrawing the Hooks Resulting in a Split Needle

We describe a most unusual problem of a split needle following a lung radiofrequency ablation (RFA) procedure. We encountered the problem when retracting the electrode hooks into the shaft at completion of the ablation. We describe the process we adopted to overcome this problem. Charring of the ablated tissue can cause the tissue to become caught in the space between the hooks and the shaft or stick to the hooks. This can prevent withdrawal of the hooks into the shaft and is therefore an important complication of which practitioners need to be aware.

Azygos arch valves at computed tomography angiography and pitfalls related to its variety in appearance and function.

Objective: To evaluate the prevalence of azygos arch valves and assess azygos valve insufficiency at computed tomography angiography (CTA) of the chest or body with high rate contrast material injection. Methods: Three hundred twenty-one CTAs using high intravenous injection rates (3-5 mL/second) of 300 mgI/mL contrast material were retrospectively evaluated for the presence of contrast material reflux from the superior vena cava into the azygos vein. Among the patients with contrast material reflux, azygos valves were identified within the azygos arch. Age, sex, and site of contrast material injection were analyzed. Azygos valve insufficiency was considered to be present if there was contrast material within the azygos vein posterior to the azygos valve. Results: Of the 321 examinations, 191 (59.5%) showed reflux into the azygos vein. There was no significant difference in frequency of reflux into the azygos vein between right and left arm injection site (56.4% vs 63.5%, P = 0.20) or male and female patients (63.4% vs 55.0%, P = 0.12). No difference in mean age was noted between patients with reflux and those without it (P = 0.97). Azygos valves were identified in 124 (64.9%) of 191 CTA examinations with contrast reflux and pitfalls related to their appearance variety are discussed. No significant difference was found in valve frequency between male and female patients (66.0% vs 63.4%, P = 0.70). Contrast material posterior to the visible azygos valve was present in 66 (53.2%) of 124 examinations. Conclusions: Azygos arch valves are a common finding on CTA. They come in various sizes and shapes, and many of them show features of insufficiency.

Controlled study of in-line ovine spleen transection assisted by radiofrequency ablation.

BACKGROUND Trauma to the spleen or tumors of the spleen often require total splenectomy for control of hemorrhage. Partial splenectomy is the preferred technique because of the short- and long-term sepsis problems in asplenic patients. Multiple techniques for partial splenectomy have been tried in the past with limited success. The authors designed the in-line radiofrequency ablation (ILRFA) probe for liver surgery. It uses radiofrequency energy to make a linear coagulative plane that allows the parenchyma of solid vascular organs to be divided. In this study, for the first time, the efficiency of ILRFA was tested with the ovine spleen. METHODS Seven sheep were used for this study. With the sheep under general anesthesia, a laparotomy was performed. The first sheep was used for a pilot study. Eight partial splenectomies were made in the remaining six sheep using ILRFA. For a control, a matching partial splenectomy was made in each sheep using diathermy and sutures. Blood loss was measured by determining the difference in the weights of dry sponges and blood-stained sponges after resection. A paired t test was used to compare the bleeding between the control and the ILRFA techniques. RESULTS The mean blood loss was 33.14 +/- 17 g using ILRFA and 123.43 +/- 72 g in the control group. The bleeding was significantly reduced in the ILRFA group (p = 0.0056). The time required to apply ILRFA was 12 minutes. CONCLUSION Partial splenectomy was achieved in the ovine spleen using radiofrequency energy with minimal blood loss.