Hydrodissection using an iodinated contrast medium during percutaneous renal cryoablation

Profile and methodology of ancillary protective measures employed during percutaneous renal cryoablation in a single high-volume centre

OBJECTIVES

To evaluate the at-risk organs that require protection during percutaneous cryoablation (PCA) of renal tumours and the correlation with patient and target lesion characteristics, type of protective measure used and postoperative outcomes.

MATERIALS AND METHODS

Single-centre retrospective review of patients with renal tumours who underwent PCA between 2008 and 2020. Final analysis included 374 tumours. Patient, tumour, and procedure technical details were extracted and analysed. At-risk organs were classified according to tumour location relative to kidney side, pyelic axis, and polar lines.

RESULTS

There were 171 (46.0%) tumours in the left kidney, and 194 (52.0%) in the right. Cryoprotection was required for 272 (272/374; 73.0%) tumours, with hydrodissection (216/374; 58.0%) being the most common technique. Protective measures were used for 82 (82/93; 88.0%) tumours in under/normal-weight patients and 143 (143/196; 73.0%) in overweight/obese ones (P = 0.004). In the left kidney, colon was the most common at-risk organ (63/171; 37.0%), followed by spleen (21/171; 12.3%), small bowel (21/171; 12.3%), ureter (19/171; 11.1%), abdominal wall (15/171; 8.8%), psoas muscle (10/171; 5.8%), and pancreas (9/171; 5.3%). In the right kidney, common at-risk organs were the colon (67/194; 35.0%), liver (50/194; 25.7%), ureter (15/194; 15.5%), diaphragm (16/194; 8.2%), abdominal wall (14/194; 7.2%), and duodenum (12/194; 6.1%). No cryoinjuries to at-risk organs occurred.

CONCLUSION

Hydrodissection is the most common cryoprotective measure used for renal tumour PCA. Under/normal-weight patients are more likely to require cryoprotection. The colon is the most common adjacent at-risk organ requiring protection for both right- and left-sided tumours.

Protection from injury to organs adjacent to a renal tumor during Imaging-guided thermal ablation with hydrodissection and pyeloperfusion

PURPOSE

The treatment of renal tumors is dictated by the results acquired from renal imaging, which play a crucial role in determining the appropriate strategy and surgical plan. Radiofrequency ablation, microwave ablation, and cryoablation are established percutaneous thermal ablation procedures that have widespread recognition. The objective of this scholarly article is to present a comprehensive summary of the application of the primary thermal protection strategies of the structures adjacent to renal tumors, in particular the effectiveness in terms of safety of hydrodissection and pyeloperfusion, in the context of percutaneous thermal ablation for renal tumors.

METHODS

A literature search was conducted in PubMed in April 2023 using the keywords "hydrodissection", "hydrodisplacement", "renal", "kidney", "percutaneous ablation", "cryoablation", "microwave", "radiofrequency", and "pyeloperfusion". No language restriction was applied.

RESULTS

Our study yielded a total of 676 cases describing the use of either hydrodissection or pyeloperfusion in conjunction with percutaneous thermal ablation. The fluids employed for displacing the neighboring structures encompassed saline solution, a mixture of saline solution and iodinated contrast, 5% dextrose in water, iodinated contrast in dextrose solution, lactated singer solution, and iodinated contrast.

CONCLUSIONS

By using these procedures effectively, a greater number of ablations could be performed on anterior or lower polar renal tumors, sometimes excluded from these treatments due to the high risk of causing damage to adjacent anatomical structures.

Propensity score-matched analysis comparing robot-assisted partial nephrectomy and image-guided percutaneous cryoablation for cT1 renal cell carcinoma

OBJECTIVES

This study aimed to compare the clinical outcomes of robot-assisted partial nephrectomy (RAPN) and image-guided percutaneous cryoablation (IG-PCA) for clinical T1 renal cell carcinoma.

MATERIALS AND METHODS

We conducted a retrospective analysis of 679 patients with clinical T1 renal cell carcinoma treated with RAPN or IG-PCA between 2012 and 2021. Propensity scores were calculated via logistic analysis to adjust for imbalances in baseline characteristics. We compared oncological and functional outcomes between the 2 treatment groups.

RESULTS

Following the matching process, 108 patients were included in each group. No patient in the RAPN group developed local recurrence. In the IG-PCA group, three patients experienced local tumor progression. The patients underwent salvage thermal ablations by the secondary technique; 2 underwent IG-PCA and 1 underwent microwave ablation, resulting in a local control rate of 100%. The Kaplan-Meier analysis showed no statistically significant differences between the groups in terms of 5-year recurrence-free survival, metastasis-free survival, and overall survival (log-rank test; P = 0.11, P = 0.64, and P = 0.17, respectively). No significant differences were observed in the 2 treatments in major and overall complication rates (P = 0.75 and P = 0.82, respectively). Both groups showed similar rates of less than 10% estimated glomerular filtration rate decline at 12 months post-treatment and 5-year renal function preservation rates (P = 0.88 and P = 0.38, respectively).

CONCLUSIONS

IG-PCA demonstrated oncological outcomes comparable to those of RAPN. RAPN addressed the disadvantages of conventional procedures and allowed for safety outcomes comparable to IG-PCA.

Percutaneous Microwave Ablation for Treatment of Retroperitoneal Tumors

Purpose To determine if microwave ablation (MWA) of retroperitoneal tumors can safely provide high rates of local tumor control. Materials and Methods This retrospective study included 19 patients (median age, 65 years [range = 46-78 years]; 13 [68.4%] men and six [31.6%] women) with 29 retroperitoneal tumors treated over 22 MWA procedures. Hydrodissection (0.9% saline with 2% iohexol) was injected in 17 of 22 (77.3%) procedures to protect nontarget anatomy. The primary outcomes evaluated were local tumor progression (LTP) and complication rates. Oncologic outcomes, including overall survival (OS), progression-free survival (PFS), and treatment-free interval (TFI), were examined as secondary outcome measures. Results Median follow-up was 18 months (range = 0.5-113). Hydrodissection was successful in displacing nontarget anatomy in 16 of 17 (94.1%) procedures. The LTP rate was 3.4% (one of 29; 95% CI: 0.1, 17.8) per tumor and 5.3% (one of 19; 95% CI: 0.1, 26.0) per patient. The overall complication rate per patient was 15.8% (three of 19), including two minor complications and one major complication. The OS rate at 1, 2, and 3 years was 81.8%, 81.8%, and 72.7%, respectively, with a median OS estimated at greater than 7 years. There was no evidence of a difference in OS (P = .34) and PFS (P = .56) between patients with renal cell carcinoma (six of 19 [31.6%]) versus other tumors (13 of 19 [68.4%]) and patients treated with no evidence of disease (15 of 22 [68.2%]) versus patients with residual tumors (seven of 22 [31.8%]). Median TFI was 18 months (range = 0.5-108). Conclusion Treatment of retroperitoneal tumors with MWA combined with hydrodissection provided high rates of local control, prolonged systemic therapy-free intervals, and few serious complications. Keywords: Ablation Techniques (ie, Radiofrequency, Thermal, Chemical), Retroperitoneum, Microwave Ablation, Hydrodissection © RSNA, 2024.

Functional and oncological outcome of percutaneous cryoablation versus laparoscopic partial nephrectomy for clinical T1 renal tumors: A propensity score-matched analysis

PURPOSE

To evaluate the clinical trifecta of percutaneous cryoablation (PCA) vs. laparoscopic partial nephrectomy (LPN) for cT1 renal tumors.

PATIENTS AND METHODS

We retrospectively analyzed the records of patients who had undergone 2 types of nephron sparing surgeries (NSS) PCA or LPN for cT1 renal tumors between November 2011 and December 2019. The cohorts were matched by one-to-one propensity scores based on patient demographics, renal function, and tumor complexity. Perioperative and oncological outcomes and preservation of renal function following surgery were compared.

RESULTS

After matching, a total of 180 patients who had undergone NSS for de novo renal tumors were evaluable: 90 for PCA and 90 for LPN. No statistically significant differences were noted among the measured baseline characteristics in the propensity score-matched cohorts. Overall perioperative complication rates were 5.5% in the PCA and 11.1% in the LPN groups (P = 0.28). The rate of eGFR preservation 1 to 3 months after surgery was significantly higher for PCA than for LPN (92.8 ± 11.5% vs. 88.5 ± 14.6%, P = 0.03). Median follow-up was 33 months for PCA and 18 months for LPN (P < 0.001). Three residual and 4 recurrent tumors were later diagnosed in the PCA group and 1 recurrent tumor in the LPN group. The 5-year local recurrence-free survival was lower for PCA than LPN (90.2% vs. 98.5%, P = 0.36). The 5-year metastasis-free survival rate was similar in both groups (98.4% vs. 100%, P = 0.38). The 5-year overall and cancer-specific survival rates were comparable in both groups (91.7% vs. 98.9%, P = 0.53, and 95% vs. 100%, P = 0.55, respectively).

CONCLUSIONS

Clinical T1 RCC patients are better treated with LPN if technically possible. Though PCA had a higher local recurrence rate, medium-term local control was not inferior to LPN. Additionally, PCA patients tended to retain renal function without severe complications. PCA appears to be a reasonable option for patients with high comorbidity at presentation.

Protection from injury of organs adjacent to a renal tumor during percutaneous cryoablation

Renal cryoablation has become accepted as treatment for small renal tumors as an alternative to surgery. However, parallel with the increase in the use of this therapy, there also has been increases in the number of reports of complications related to renal cryoablation. One potential complication is injury to important non-renal structures adjacent to the ablated renal tumor, such as the colon, duodenum, ureter, psoas muscle and so on. To prevent injury of adjacent organs, separating organs from the tumor is desirable. Over the past 15 years, several techniques have been developed to protect against injury of organs adjacent to renal tumors that are targets of cryoablation. The most commonly used technique for this purpose has been hydrodissection. Others include dissection with gas, balloon dissection and probe traction. To avoid injury of a ureter running near the renal tumor, pyeloperfusion is known to be useful. The rate of cases necessitating avoidance of organ injury by using these techniques is relatively high. In some cases, more than two techniques are combined. In the present review, we provided an overview of techniques currently available to protect against organ injuries, and discussed the advantages and disadvantages of each technique.

Ureteral protection during microwave ablation of renal cell carcinoma: combined use of pyeloperfusion and hydrodissection

A 56-year-old female with past medical history of thrombotic microangiopathy presented to her physician with nonspecific abdominal pain. A magnetic resonance imaging scan was obtained, which revealed a 3.1 cm mass arising from medial lower pole of the left kidney that was subsequently shown to be renal cell carcinoma by percutaneous biopsy. Because of her history of thrombotic microangiopathy and other comorbidities, she was deemed a nonsurgical candidate and was therefore referred to interventional radiology for thermal ablation. Computed tomography (CT)-guided microwave ablation was performed with the combined use of pyeloperfusion and hydrodissection for maximal ureteral protection. Follow-up unenhanced CT scan obtained one month after ablation showed a normal collecting system without evidence of hydronephrosis or urinoma.

Clinical Application of Artificial Ascites in assisting CT-guided Percutaneous Cryoablation of Hepatic Tumors Adjacent to the Gastrointestinal Tract

This study was to assess the safety and efficacy of artificial ascitetes in assisting CT-guided cryoablation of hepatic tumors adjacent to the gastrointestinal (GI) tract. A total of 84 patients with peripheral hepatic tumors adjacent to the GI tract, who were treated cryoablation, were included in this retrospective study. Of these 84 patients, cryoablation had been performed in 39 patients with 41 peripheral hepatic tumors. These were assisted by induction artificial ascites while 40 patients with 43 peripheral hepatic tumors underwent cryoablation without induction of ascites. The artificial ascites separation success rate, the cryoablation technique effectiveness, local tumor progression and complications were all evaluated. The results showed that the artificial ascites separation success rate for 41 hepatic tumors adjacent to the GI tract was 95% (39/41). Technique effectiveness of group I was achieved in 35 of 43 tumors (81.3%) after follow-up imaging three months after cryoablation. In group II, technique effectiveness was achieved in 39 of 41 tumors after follow-up imaging three months following cryoablation. No major complications were encountered in either of the two groups. Artificial ascites assisting in CT-guided percutaneous cryoablation is a reliable and effective method for the treatment of hepatic tumors adjacent to the GI tract, and it can achieve a fine local control of such tumors.

[Percutaneous renal ablation: Pre-, per-, post-interventional evaluation modalities and adapted management]

OBJECTIVES

Ablative treatment (AT) rise is foreseen, validation of steps to insure good proceedings is needed. By looking over the process of the patient, this study evaluates the requirements and choices needed in every step of the management.

METHODS

We searched MEDLINE^®, Embase^®, using (MeSH) words and we looked for all the studies. Investigators graded the strength of evidence in terms of methodology, language and relevance.

RESULTS

Explanations of AT proposal rather than partial nephrectomy or surveillance have to be discussed in a consultation shared by urologist and interventional radiologist. Per-procedure choices depend on predictable ballistic difficulties. High volume, proximity of the hilum or of a risky organ are in favor of general anesthesia, cryotherapy and computed tomography/magnetic resonance imaging (CT/MRI). Percutaneous approach should be privileged, as it seems as effective as the laparoscopic approach. Early and delayed complications have to be treated both by urologist and radiologist. Surveillance by CT/MRI insure of the lack of contrast-enhanced in the treated area. Patients and tumors criteria, in case of incomplete treatment or recurrence, are the key of the appropriate treatment: surgery, second session of AT, surveillance.

CONCLUSION

AT treatments require patient's comprehension, excellent coordination of the partnership between urologist and radiologist and relevant choices during intervention.

Angio-CT-Assisted Balloon Dissection: Protection of the Adjacent Intestine during Cryoablation for Patients with Renal Cancer

The present study describes the technical feasibility of a combined-modality angiography/computed tomography (angio-CT)-assisted balloon dissection technique for bowel protection during renal cryoablation in six procedures in five patients. A retrospective review was performed to evaluate balloon dissection using the angio-CT system. Mean bowel-to-tumor distances before and after balloon dissection were 0.9 mm (range, 0-3 mm) and 13.0 mm (range, 11-17 mm), respectively. No bowel injury was observed during the mean follow-up period of 19 months (range, 7-44 mo). Our preliminary experience suggests that balloon dissection using the angio-CT system for bowel protection during renal cryoablation may be feasible and effective.

Percutaneous Cholecystostomy and Hydrodissection in Radiofrequency Ablation of Liver Subcapsular Leiomyosarcoma Metastasis Adjacent to the Gallbladder: Protective Effect

Uterine leiomyosarcoma is an uncommon pathology, predominantly found in aged population. Patients with metastatic disease have poor survival and therapy mainly consists of palliative systemic chemotherapy. However, more aggressive strategies such as radiofrequency ablation (RFA) may benefit patients with limited secondary disease. RFA is considered a simple and safe modality for treatment of hepatic lesions. The benefits related to RFA include low morbidity, short hospital stay and the possibility to repeat the procedure when necessary due to recurrences. However, minor and major complications related to mechanical and thermal damage may occur, especially in cases of tumors adjacent to extrahepatic organs and those at subcapsular position. This case report shows a successful RFA of two hepatic subcapsular leiomyosarcoma metastases neighbouring the gallbladder, without a safe cleavage plane from it. Combined hydrodissection, percutaneous cholecystostomy and continuous irrigation were performed as effective techniques to prevent thermal injury. Clinical and radiological follow up demonstrates no local complication.

Hepatic Tumor Ablation

Tumor ablation is a safe and effective treatment available in the multidisciplinary care of the surgical oncology patient. The role of ablation is well established in the treatment of hepatocellular carcinoma and is becoming more accepted in the treatment of various malignancies metastatic to the liver, in particular colorectal cancer. Understanding the underlying technology, achieving appropriate applicator placement, using maximum energy delivery to create margins, and performing necessary adjunctive maneuvers are all required for successful tumor ablation.

Interventional oncology: pictorial review of post-ablation imaging of liver and renal tumors

Percutaneous image-guided ablation is now commonly performed in many institutions for the treatment of hepatocellular carcinoma, liver metastases, and renal cell carcinoma in select patients. Accurate interpretation of post-ablation imaging is of supreme importance because treatment algorithms for these diseases rely heavily on imaging to guide management decisions. The purpose of this pictorial essay is to provide abdominal imagers with a review of the indications for percutaneous ablation in the abdomen, a basic overview of ablation modalities in clinical use today, the expected post-ablation imaging findings in the liver and kidney, and potential complications of hepatic and renal ablation procedures.

Percutaneous tumor ablation tools: microwave, radiofrequency, or cryoablation--what should you use and why?

Image-guided thermal ablation is an evolving and growing treatment option for patients with malignant disease of multiple organ systems. Treatment indications have been expanding to include benign tumors as well. Specifically, the most prevalent indications to date have been in the liver (primary and metastatic disease, as well as benign tumors such as hemangiomas and adenomas), kidney (primarily renal cell carcinoma, but also benign tumors such as angiomyolipomas and oncocytomas), lung (primary and metastatic disease), and soft tissue and/or bone (primarily metastatic disease and osteoid osteomas). Each organ system has different underlying tissue characteristics, which can have profound effects on the resulting thermal changes and ablation zone. Understanding these issues is important for optimizing clinical results. In addition, thermal ablation technology has evolved rapidly during the past several decades, with substantial technical and procedural improvements that can help improve clinical outcomes and safety profiles. Staying up to date on these developments is challenging but critical because the physical properties underlying the different ablation modalities and the appropriate use of adjuncts will have a tremendous effect on treatment results. Ultimately, combining an understanding of the physical properties of the ablation modalities with an understanding of the thermal kinetics in tissue and using the most appropriate ablation modality for each patient are key to optimizing clinical outcomes. Suggested algorithms are described that will help physicians choose among the various ablation modalities for individual patients.

Percutaneous tumor ablation tools: microwave, radiofrequency, or cryoablation--what should you use and why?

Image-guided thermal ablation is an evolving and growing treatment option for patients with malignant disease of multiple organ systems. Treatment indications have been expanding to include benign tumors as well. Specifically, the most prevalent indications to date have been in the liver (primary and metastatic disease, as well as benign tumors such as hemangiomas and adenomas), kidney (primarily renal cell carcinoma, but also benign tumors such as angiomyolipomas and oncocytomas), lung (primary and metastatic disease), and soft tissue and/or bone (primarily metastatic disease and osteoid osteomas). Each organ system has different underlying tissue characteristics, which can have profound effects on the resulting thermal changes and ablation zone. Understanding these issues is important for optimizing clinical results. In addition, thermal ablation technology has evolved rapidly during the past several decades, with substantial technical and procedural improvements that can help improve clinical outcomes and safety profiles. Staying up to date on these developments is challenging but critical because the physical properties underlying the different ablation modalities and the appropriate use of adjuncts will have a tremendous effect on treatment results. Ultimately, combining an understanding of the physical properties of the ablation modalities with an understanding of the thermal kinetics in tissue and using the most appropriate ablation modality for each patient are key to optimizing clinical outcomes. Suggested algorithms are described that will help physicians choose among the various ablation modalities for individual patients.