Endophytic Lesions: A Predictor of Failure in Laparoscopic Renal Cryoablation

Percutaneous Cryoablation of Renal Tumors: Initial Indian Experience

Objective The purpose of this study was to report short-term outcomes of cryoablation of early-stage renal tumors (T1a and T1b) at a tertiary hospital in India.

Methods This was a retrospective study of consecutive patients who underwent cryoablation for renal cell carcinoma (RCC) from November 2018 to June 2020. Cryoablation was performed under combined ultrasound and computed tomography guidance using a helium-argon cryoablation system. Tumor number, size, location, nephrometry score, relationship of the tumor with pelvicalyceal system, and adjacent organs were tabulated, and technical and clinical success evaluated. Early and late recurrence and complications were also assessed.

Results Eleven patients (median age: 62 years) with 11 tumors underwent cryoablation. The mean tumor size was 2.58 cm (range: 1.62–5.62 cm) with 10 lesions being T1a and one lesion T1b. Tissue sampling was done in 9/11 patients, 3 were papillary RCC and the rest, clear cell RCC. In two patients, the tumor was completely endophytic, three patients had partially endophytic tumors while 6 patients had exophytic lesions. The median nephrometry score was 6 (range: 4–11, Mode 4). Technical success was achieved in all patients. Complete response was achieved in 81% (9/11) of the patients at 1-month follow-up. Median follow-up period was 6 months. Two patients showed residual disease on follow-up imaging at 1 and 3 months, respectively.

Conclusion Cryoablation is a promising, relatively new minimally invasive therapy for treating small renal tumors in India. It is safe, technically feasible, and shows excellent short-term efficacy.

Laparoscopic ultrasonography: The wave of the future in renal cell carcinoma?

Laparoscopic or robotic surgery is the main method of treating renal cell carcinoma (RCC). Laparoscopic surgery can accurately target lesions and shorten patient recovery time. Renal endogenous tumors or inferior vena cava tumor thrombi are very difficult to remove using the laparoscopic approach. The emergence of laparoscopic ultrasonography (LUS) has solved this problem. LUS can assist in the detection of tumor boundaries and the extent of tumor thrombi. The lack of tactile feedback may hinder the development of laparoscopic surgery for the treatment of renal cancer. LUS has become an important tool that has improved the rates of successful surgery. LUS is applied in not only early and locally advanced RCC treatment but also in monitoring ablation therapy, testing renal blood perfusion, and exposing renal pedicles. Sonographic techniques used for LUS include initial B-mode, Doppler, and contrast-enhanced ultrasound (CEUS). Contrast agents applied for CEUS do not induce nephrotoxicity and can display renal perfusion more accurately than the regular color Doppler ultrasound. According to current literature, LUS is a promising technique for the treatment of RCC, especially for endogenous RCC or RCC with thrombosis, and for monitoring the effectiveness of radiofrequency ablation, although further well-designed studies are warranted.

Arterial Clamping Increases Central Renal Cryoablation Efficacy: An Animal Study

INTRODUCTION

The minimally invasive treatment of small renal masses with cryoablation has become increasingly widespread during the past 15 years. Studies with long-term follow-up are beginning to emerge, showing good oncological control, however, tumors with a central and endophytic location seem to possess an increased risk of treatment failure. Such tumors are likely to be subjected to a high volume of blood giving thermal protection to the cancerous cells. Arterial clamping during freezing might reduce this effect but at the same time subject the kidney to ischemia. The aim of this study was to evaluate the effect of renal artery clamping during cryoablation in a porcine survival model.

METHODS

Ten Danish Landrace pigs (approximately 40 kg) underwent bilateral laparoscopic cryoablation with clamping of the right renal artery during freezing. The cryoablation consisted of a standard double-freeze cycle of 10-minute freeze followed by 8 minutes of thaw. Arterial clamping subjected the right kidney to 2 cycles of ischemia (10 minutes) with perfusion in between. After surgery, the animals were housed for 14 days prior to computed tomography perfusions scans, radioisotope renography, and bilateral nephrectomy.

RESULTS

No perioperative or postoperative complications were experienced. Mean differential renal function was 44% (95% confidence interval: 42-46) in the clamped right kidney group and 56% (95% confidence interval: 54-58) in the nonclamped left kidney group, P < .05. The ±5% technical inaccuracy is not accounted for in the results. Mean maximum temperature between freeze cycles was 5.13°C (95% confidence interval: -0.1 to 10.3) in the clamped right kidney group and 22.7°C (95% confidence interval: -16.6 to 28.8) in the nonclamped left kidney group, P < .05. Mean cryolesion volume, estimated on computed tomography perfusion, was 12.4 mL (95% confidence interval: 10.35-14.4) in the clamped right kidney group and 6.85 mL (95% confidence interval: 5.57-8.14) in the nonclamped left kidney group, P < .05. Pathological examination shows a higher degree of vital cells in the intermediate zone of the cryolesions in the nonclamped left kidneys when compared with the clamped right kidneys.

CONCLUSION

Arterial clamping increases cryolesion size by approximately 80%, and pathologic examinations suggest a decreased risk of vital cells in the intermediate zone. The clamped kidneys showed no sign of injury from the limited ischemic insult. This study was limited by being a nontumor model.

Current status of cryotherapy for prostate and kidney cancer

In terms of treating diseases, minimally invasive treatment has become a key element in reducing perioperative complications. Among the various minimally invasive treatments, cryotherapy is often used in urology to treat various types of cancers, especially prostate cancer and renal cancer. In prostate cancer, the increased incidence of low-risk, localized prostate cancer has made minimally invasive treatment modalities an attractive option. Focal cryotherapy for localized unilateral disease offers the added benefit of minimal morbidities. In renal cancer, owing to the increasing utilization of cross-sectional imaging, nearly 70% of newly detected renal masses are stage T1a, making them more susceptible to minimally invasive nephron-sparing therapies including laparoscopic and robotic partial nephrectomy and ablative therapies. This article reviews the various outcomes of cryotherapy compared with other treatments and the possible uses of cryotherapy in surgery.

Review of the efficacy and safety of cryoablation for the treatment of small renal masses

PURPOSE

Small renal masses are increasingly being discovered incidentally on imaging for another reason. The standard of care of these masses involves excision by open or laparoscopic techniques. Recently, ablative techniques, such as radiofrequency ablation (RFA) and cryoablation, have taken a more prominent role in the treatment algorithm of these masses. We evaluate the effectiveness and safety of cryoablation to treat renal tumours.

METHODS

A review of the literature was conducted. There was no language restriction. Studies were obtained from the following sources: the Cochrane Library, PUBMED, EMBASE and LILACS.

RESULTS

There was no clinical trial identified in the literature. Thus, we described the results from 23 case series and retrospective studies with a reasonable sample size (number of reported patients in each study ≥30), with a total of 2104 analyzed tumours from 2038 patients. There was wide variability in the outcomes reported, but success rates were generally good. Follow-up was generally short, but some series reported outcomes at 5 years. The most common complications reported were hemorrhage (some of the patients requiring transfusion), perinephric hematoma and urine leaks.

CONCLUSION

Cryoablation presents a feasible treatment for patients with small renal masses. Only short-term data are available and, as such, meaningful conclusions regarding long-term cancer control cannot be made. More rigorous studies are needed.

Anatrophic nephrotomy as nephron-sparing approach for complete removal of intraparenchymal renal tumors

OBJECTIVE

Partial nephrectomy for small kidney tumors has increased in the last decades, and the approach to non-palpable endophytic tumors became a challenge, with larger chances of positive margins or complications. The aim of this study is to describe an alternative nephron-sparing approach for small endophytic kidney tumors through anatrophic nephrotomy.

PATIENTS AND METHODS

A retrospective analysis of patients undergoing partial nephrectomy at our institution was performed and the subjects with endophytic tumors treated with anatrophic nephrotomy were identified. Patient demographics, perioperative outcomes and oncological results were evaluated.

RESULTS

Among the partial nephrectomies performed for intraparenchymal tumors between 06/2006 and 06/2010, ten patients were submitted to anatrophic nephrotomy. The mean patient age was 42 yrs, and the mean tumor size was 2.3 cm. Mean warm ischemia time was 22.4 min and the histopathological analysis showed 80% of clear cell carcinomas. At a mean follow-up of 36 months, no significant creatinine changes or local or systemic recurrences were observed.

CONCLUSION

The operative technique described is a safe and effective nephron-sparing option for complete removal of endophytic renal tumors.

Contrast enhancement on computed tomography after renal cryoablation: an evidence of treatment failure?

BACKGROUND AND PURPOSE

Renal cryoablation has gained popularity as a treatment option for localized renal masses. Treatment success is typically defined by the absence of contrast enhancement on follow-up imaging. We investigate the evolution of lesions that demonstrate contrast enhancement on CT after renal cryoablation.

PATIENTS AND METHODS

Retrospective review of records of laparoscopic and percutaneous cryoablation (LCA and PCA) was performed, identifying records with postoperative radiographic enhancement. Imaging studies were reviewed and radiographic (pre- and post-contrast Hounsfield units, pattern and location of enhancement) and clinical data including follow up were collected.

RESULTS

One hundred and seventy-two cryoablation procedures were analyzed. Of these, 30 (17.4%) showed enhancement on follow-up CT. In 28 cases, contrast enhancement was demonstrated on the first postoperative study. Seven patients underwent salvage treatments. Spontaneous resolution of enhancement was noted in 17 (56.7%) cases. No association was found between enhancement pattern (diffuse/nodular/rim) and resolution. Of lesions enhancing >35 HU, only 14.3% resolved spontaneously. Delayed enhancement (after negative imaging studies) occurred in two patients; both underwent salvage treatments.

CONCLUSIONS

Most of the time, contrast-enhancements after cryoablation are evident on the first follow-up imaging study. More than 50% of these resolve spontaneously, and only one of four patients need salvage treatment. Delayed appearance of enhancement after previously negative imaging and highly enhancing lesions (>35 HU) are unlikely to resolve and should be considered suspicious for local recurrence or incomplete ablation. Further investigation is warranted to reach a consensus on a radiographic definition of local recurrence after renal cryoablation.

Percutaneous cryoablation of renal tumors: patient selection, technique, and postprocedural imaging

Percutaneous cryoablation of renal tumors requires a number of important steps for success and relies heavily on imaging for treatment planning, intraprocedural guidance and monitoring, detection of untreated tumor, and surveillance for disease progression. Imaging-guided percutaneous cryoablation has several advantages over laparoscopic cryoablation. In particular, computed tomography (CT) and magnetic resonance (MR) imaging allow global evaluation of the ablation zone and an accurate depiction of the treatment margin. Ultrasonography allows real-time guidance of probe placement but cannot help depict ice ball formation as accurately as CT or MR imaging. Multiphasic CT or MR imaging should be performed at structured intervals following ablation. Treated tumors are expected to decrease in size over time, and lesion growth and internal or nodular enhancement are suspicious for tumor recurrence or progression. Complications include probe site pain, hematoma, incomplete ablation, and recurrent tumor. Current limitations of percutaneous cryoablation include the inability to control hemorrhage without intraarterial access and a lack of long-term follow-up data. Nevertheless, percutaneous cryoablation is an effective choice for minimally invasive nephron-sparing treatment of renal tumors.

Efficacy of laparoscopic renal cryoablation as an alternative treatment for small renal mass in patients with poor operability: experience from the Korean single center

OBJECTIVE

The aim of this work was to evaluate the efficacy and safety of laparoscopic renal cryoablation (LRC) for the treatment of incidentally found small renal masses in patients with poor operability, from our initial experience in Korea.

MATERIALS AND METHODS

From June 2005 to April 2009, surgical and oncologic outcomes were evaluated from a database of 45 renal tumors in 39 patients who underwent LRC due to a high American Society of Anesthesiology (ASA) physical status score (i.e., over 3) or old age (i.e., over 70 years old).

RESULTS

Mean (range) age was 63.3 years (range, 43-81), and mean tumor size was 2.5 cm (range 0.7-3.9). Mean of ASA physical status score of whole patients was 2.8 (range, 1-4), and 79.4% (31/39) of patients had an ASA physical status score over 3. Eleven patients (28.2%) were over 70 years old. Among 45 treated lesions, 23 (51.1%) were exophytic tumors, 17 (37.8%) were endophytic tumors, and the other 5 (11.1%) were mesophytic tumors. Mean operating time was 173.7 minutes (range, 110-220), and mean blood loss was 106.3 mL (range, 40-150). None of the patients developed major complications, including adjacent organ injury, collecting system injury, open surgical conversion, or conversion to nephrectomy. Pathologic examination revealed that 60% (27/45) of lesions were renal-cell carcinoma (RCC). During a mean follow-up duration of 23.5 months (range, 6-53), radiologic evidence of tumor recurrence was found in 1 patient (3.7% for RCC). With the exception of this patient, all other patients have remained free of recurrence or metastasis, as determined by a periodic radiologic work-up. Serum creatinine remains stable, with no statistical difference, compared to preoperative levels, in both whole patients and patients with solitary kidney.

CONCLUSIONS

In this series, LRC for small renal tumors showed favorable oncologic and surgical outcomes, including maintenance of renal function, without adverse effects in selected patients with poor operability.

Cryoablation for endophytic renal cell carcinoma: intermediate-term oncologic efficacy and safety

Purpose

To evaluate the efficacy and safety of laparoscopic renal cryoablation (LRC) of small endophytic renal cell carcinoma, for which surgical treatment is technically difficult.

Materials and Methods

We enrolled patients with endophytic tumors from a prospectively collected database of 45 renal tumors in 39 patients who had undergone LRC from June 2005 to May 2009. An endophytic tumor was defined as less than 40% of the lesion extending off the surface of the kidney. We evaluated surgical and oncological outcomes.

Results

Among the treated tumors, 17 tumors (37.8%) were defined as endophytic tumors and 15 tumors from 14 patients were confirmed as renal cell carcinoma (RCC) in the pathologic examination of the tissue biopsy that was conducted at the time of LRC. The mean American Society of Anesthesiologists (ASA) score of the whole patient group was 2.9 (range, 1-4), and 85.7% (12/14) of the patients had an ASA physical status score over 3. The mean tumor size was 2.8 cm (range, 1.7-3.7 cm). The layout of the cryoprobe was carefully planned preoperatively on the basis of radiologic evaluation in all tumors. Multiple cryoprobes (mean, 3.2; range, 2-5) were used. No major complications, including open surgical conversion and nephrectomy due to bleeding, occurred. No patient experienced clinical symptoms of collecting system injuries. During the mean follow-up of 32.6 months (range, 12-51 months), radiologic evidence of tumor recurrence was found in one patient (6.7% for RCC). With the exception of this patient, all other patients have remained free of recurrence or metastasis, as determined by periodic radiologic workups.

Conclusions

In this series of patients with intermediate-term follow-up, LRC for endophytic renal cell carcinoma showed acceptable oncological and surgical outcomes without sequelae in the collecting system.

The impact of renal tumor size on the efficacy of laparoscopic renal cryoablation

PURPOSE

We evaluated the impact of renal tumor size on the oncologic and surgical efficacy of laparoscopic renal cryosurgery (LRC) according to our intermediate-term experience in Korea.

MATERIALS AND METHODS

From June 2005 to October 2008, we enrolled 37 patients who underwent LRC for 40 renal tumors. Patients were stratified into four groups according to renal tumor size. Patients who presented with a maximum tumor diameter (MTD) of at least 1 cm but less than 2 cm were assigned to Group 1, those with an MTD equal to or greater than 2 but less than 3 cm were assigned to Group 2, those with an MTD equal to or greater than 3 but less than 4 cm were assigned to Group 3, and those with an MTD equal to or greater than 4 cm were assigned to Group 4. Oncologic and clinical outcomes in each group were compared.

RESULTS

The four groups showed no statistically significant differences in preoperative variables, including age, sex, body mass index, American Society of Anesthesiologists scores, baseline renal function and hemoglobin, and length of hospital stay. Regarding surgical aspects, however, operation time, estimated blood loss, and postoperative complications were significantly increased in patients with larger tumors. Three patients in Group 3 required postoperative transfusions, and 1 patient in Group 4 required conversion to open renal cryosurgery. During the mean follow-up period of 31.6 months, radiologic evidence of tumor recurrence was found in only 2 patients in Group 4.

CONCLUSIONS

In this series, LRC for renal tumors smaller than 3 cm was conducted safely without radiologic evidence of tumor recurrence during intermediate-term follow-up. For tumors larger than 3 cm, however, the transfusion rate increased, and for renal tumors larger than 4 cm, the tumor recurrence rate increased significantly.

Tumor size and endophytic growth pattern affect recurrence rates after laparoscopic renal cryoablation

OBJECTIVE

To analyze factors that may contribute to local relapse after laparoscopic cryoablation (LCA) of renal tumors. LCA has gained popularity in the treatment of small renal tumors, but local tumor control remains a concern.

METHODS

We analyzed 163 patients who underwent LCA between 2001 and 2008 either at Allegheny General Hospital or Duke University Medical Center, with at least 6 months of follow-up. Demographics, perioperative variables, tumor characteristics (size, pattern of growth, and biopsy results), and follow-up were recorded. Growth pattern was categorized as exophytic, mesophytic, or endophytic. Regression analyses were performed to evaluate risk factors for local relapse after LCA.

RESULTS

Median patient age was 66 (range, 33-90) years, with men comprising 60.1% of the cohort. Median tumor size was 2.4 cm (range, 0.5-5.0). Pathology was as follows: renal cell carcinoma in 118 (72.4%), other malignancies in 2 (1.2%), and no malignancy in 43 (26.4%) patients. A single lesion was treated in 95.1% patients and multiple tumors in 4.9%. Endophytic growth pattern was present in 22.8% patients. We observed 7 (4.3%) local recurrences over a median follow-up of 20 months (range, 6-79). Median time to recurrence was 15 months (range, 6-48). On proportional hazards regression, tumor size and endophytic growth pattern were significantly associated with local recurrence (P = .003 and .028; odds ratios [OR] = 4.1 and 11.4, respectively).

CONCLUSIONS

LCA demonstrated good tumor control over a 5-year follow-up, with an acceptable recurrence rate. Larger tumors and those with endophytic growth pattern may be at increased risk of relapse after LCA.

Decision tree for laparoscopic partial nephrectomy versus laparoscopic renal cryoablation for small renal masses

PURPOSE

We propose an algorithm to help guide surgeons' decisions between laparoscopic partial nephrectomy (LPN) and renal laparoscopic cryoablation (LCA) based on preoperative parameters and outcomes defined in the literature.

PATIENTS AND METHODS

From July 2004 to December of 2007, we performed 51 LPNs and 22 LCAs. We formulated an algorithm between LPN and LCA based on outcomes from published series. Candidates for LPN are younger than 70 years; have few comorbidities; masses < or = 7 cm; and solitary, solid, and or cystic masses with an exophytic or mesophytic location. Candidates for LCA are 70 years old or older, with multiple comorbidities, masses < or = 3.5 cm, multiple masses, solid masses only, and include endophytic or hilar tumors. We then applied this decision tree to our series.

RESULTS

Our results for LPN are statistically similar to the published series except there was a higher positive margin rate in our series (11.8 v 3.5%). Our LCA series had older patients (71 v 65 y), larger masses (3.2 v 2.5 cm), and a higher rate of bleeding necessitating transfusion (18%). We applied the algorithm to all 73 patients in our series. It estimated that 45 patients should undergo LPN and 28 should undergo LCA. A correlation between the predicted surgery and the surgery performed was seen, but approximately one in five patients would have a change in the surgery performed.

CONCLUSIONS

This algorithm validates decisions surgeons are already making between LPN and LCA. While not a perfect model, it can be used to help simplify decisions between these two minimally invasive procedures to achieve optimal outcomes.

Computed tomography and magnetic resonance imaging appearance of renal neoplasms after radiofrequency ablation and cryoablation

Thermal ablation procedures including radiofrequency ablation and cryoablation have been increasingly used for treatment for small renal cell carcinoma. Currently, computed tomography and magnetic resonance imaging are usually used to assess residual or recurrent disease after thermal ablation of renal tumor. After thermal ablation, the zone of ablation is usually seen as an area of hypoattenuation on computed tomography and is generally hypointense at T2-weighted magnetic resonance imaging and iso- to hyperintense at T1-weighted imaging relative to renal parenchyma. The ablation zone frequently involutes over time. Residual tumor after thermal ablation is most common at the margin of the ablation zone and often seen as nodular or crescent-shaped areas of contrast enhancement. Accurate assessment of ablated tumors at postprocedural imaging is essential for evaluating the adequacy of treatment and guiding further management. Complications are uncommon and usually minor but should be detected on postprocedural imaging studies.

Minimally invasive surgery using ablative modalities for the localized renal mass

Due to a number of evolving devices and modalities to treat the small, localized renal mass, the physician and patient have the opportunity to choose an appropriate therapy from several treatment options. Minimally invasive surgery to ablate a localized renal tumor is an alternative strategy to nephron-sparing surgery for the small renal mass. Even though partial nephrectomy has been established as an optimal technique for nephron-sparing surgery, patients who have comorbidities and renal insufficiency would potentially benefit from less invasive treatment. With respect to those concerns, several articles are discussed here regarding thermal ablative therapy for the small renal mass along with oncological outcomes and complications among these modalities compared to conventional procedures. In this review, a comprehensive PubMed search was conducted. For the purposes of reviewing the current status of thermal ablative modalities for the small renal mass, only articles written in English published from 1992 to 2009 were considered. Cryoablation and radiofrequency ablation are the most utilized and potentially promising therapies that are evolving as nephron-sparing minimally invasive surgery for patients with a localized renal tumor. High-intensity focused ultrasound, a relatively new modality to treat the renal mass, needs further study. All modalities require long-term follow up with unified reporting methods in terms of patient selection, pre- and post-treatment evaluation, treatment description, and analysis of outcome.

A matched-cohort comparison of laparoscopic renal cryoablation using ultra-thin cryoprobes with open partial nephrectomy for the treatment of small renal cell carcinoma

PURPOSE

To evaluate the feasibility and efficacy of performing laparoscopic renal cryoablation (LRC) for the treatment of RCC, as compared with open partial nephrectomy (OPN), which is the established NSS.

MATERIALS AND METHODS

From April 2004, among the patients who underwent LRC with a 1.47 mm cryoprobe, we enrolled 20 patients who were pathologically confirmed as having RCC with a tumor size smaller than 4 cm. These patients were matched with a group of 20 patients, who were selected based on the pre-operative characteristics of the tumor and those of the patients, from a pre-existing database of the patients who underwent OPN during the same period.

RESULTS

The mean age and tumor size were 56.3+/-11.5 years and 2.4+/-1.7 cm in the LRC group, and 57.6+/-10.9 years and 2.2+/-1.1 cm in the OPN group. The two groups were similar for their age, gender, BMI, ASA, the tumor characteristics and the indications for operation. While the pathologic results and the operation time showed similarity, the EBL (98+/-87 ml vs 351+/-147 ml, respectively, p=0.001), the transfusion rate (10% vs 40%, respectively, p=0.03) and the hospital stay (4.2+/-1.5 days vs 8.2+/-2.4 days, respectively, p=0.005) were significantly less in the LRC group. Major complications did not occur in the LRC group, but in the OPN group, one patient experienced urine leakage and one patient had a perirenal hematoma. During the mean follow up of 27.3+/-10.8 months and 28.7+/-14.9 months for each group, respectively, all the patients remained disease-free with no evidence of local recurrence or metastases.

CONCLUSIONS

LRC using ultra-thin cryoprobes for the treatment of small RCC showed similar effective oncologic results with the merits of minimal invasiveness, as compared with OPN, during the intermediate term follow up.