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Complications of Laparoscopic and Percutaneous Renal Cryoablation in a Single Tertiary Referral Center
EUROPEAN UROLOGY 58 (2010) 142–148
available at www.sciencedirect.com journal homepage: www.europeanurology.com
Endo-urology
Complications of Laparoscopic and Percutaneous Renal Cryoablation in a Single Tertiary Referral Center Matvey Tsivian a, Valerie H. Chen a, Charles Y. Kim b, Dorit E. Zilberman a, Vladimir Mouraviev a, Rendon C. Nelson b, David M. Albala a, Thomas J. Polascik a,* a
Division of Urology, Department of Surgery, Duke University Medical Center, Durham, NC, USA
b
Department of Radiology, Duke University Medical Center, Durham, NC, USA
Article info
Abstract
Article history: Accepted March 19, 2010 Published online ahead of print on March 30, 2010
Background: Laparoscopic cryoablation (LCA) and percutaneous cryoablation (PCA) of small renal masses have gained popularity, but only limited data exist on the complication rates. Objectives: In this study, we report on postoperative complications associated with LCA and PCA in a single tertiary center experience. Design, setting, and participants: We conducted a retrospective review of electronic medical records for patients undergoing LCA or PCA between 2001 and 2008 at our institution. Interventions: All patients underwent LCA or PCA. Measurements: Demographics, radiographic variables, and complication rates were compared between the two groups. Complications were classified according to the modified Clavien system. Results and limitations: Of a total of 195 patients included in this study, 72 underwent LCA and 123 underwent PCA. There were no differences in demographics between the groups. We observed complications in 10 LCA procedures (13.9%) and 26 PCA procedures (21.1%) ( p = 0.253). The distribution of the complications differed significantly between the groups with mild complications (grades 1 and 2) more common in the PCA group (20.3% vs 5.6%, respectively; p = 0.001), whereas severe events (grades 3 and 4) were more frequent in the LCA group (8.3% vs 0.8%, respectively; p = 0.011). On multivariate analysis, age and body mass index were inversely associated with complications, whereas female gender, multiple tumors, and preexisting comorbidities showed a trend toward increased risk. Conclusions: LCA and PCA, although minimally invasive, are not void of complications. Most of the complications encountered are mild; however, severe (grade 3 or 4) events may occur in up to 3.6% of patients. PCA may be associated with a higher rate of complications, although most of these are mild and transient. However, on multivariate analysis, the chosen ablative approach (laparoscopic or percutaneous) is not associated with the risk of complications.
Keywords: Complications Cryoablation Laparoscopic Percutaneous Renal neoplasm
# 2010 European Association of Urology. Published by Elsevier B.V. All rights reserved. * Corresponding author. Duke University Medical Center, Box 2804, Yellow Zone, Durham, NC 27710, USA. Tel. +1 919 684 4946; Fax: +1 919 684 5220. E-mail address: [email protected] (T.J. Polascik). 0302-2838/$ – see back matter # 2010 European Association of Urology. Published by Elsevier B.V. All rights reserved.
doi:10.1016/j.eururo.2010.03.035
EUROPEAN UROLOGY 58 (2010) 142–148
1.
2.2.
Introduction
The extensive use of computed tomography (CT) and magnetic resonance imaging has brought about a concomitant increase in the incidental detection of small renal masses. The current standard of care is surgical resection; however, alternative approaches such as cryoablation have been accepted as a viable treatment option for localized renal masses in appropriate candidates [1]. Laparoscopic cryoablation (LCA) and percutaneous cryoablation (PCA) are gaining popularity as an alternative to conventional surgery for their minimally invasive nature and good oncologic outcomes [2]. The minimally invasive nature, however, does not necessarily translate to a lower complication rate. Only scattered reports are available in the literature regarding the complications of these procedures, especially in a comparative fashion in an academic referral center [3–7]. In this paper we report on the complications associated with LCA and PCA in a single tertiary-center experience.
143
Percutaneous cryoablation procedure
All PCA procedures performed since 2005 have used low-resolution and low-mA CT-fluoroscopy for guidance. The patient was placed in a prone or decubitus position based on the location of the lesion. A radiopaque strip was placed on the flank, and a diagnostic CT was performed to identify the lesions and plan the probe insertion paths. Contrastenhanced images were obtained if the lesion could not be definitely identified with noncontrast images. The flank was draped and prepped and the probe entry site anaesthetized with 1% lidocaine. Under moderate conscious sedation, the skin was punctured with a scalpel at the entry site. If the lesion was in close proximity to a vulnerable structure such as the bowel, hydrodissection was performed by infusion of normal saline (n = 16; 13%). A 14-gauge cryoprobe (Endocare, Irvine, CA, USA) was advanced into the lesion and held in place with a short freeze. Additional probes, if needed, were positioned in a similar fashion. A median of 2 (IQR: 1–3) probes were used, with an additional 2 (IQR: 1– 3) probes used in cases with multiple tumors. After verification of correct positioning of the probes, a standard 10-min freeze/8-min thaw/10-min freeze/final thaw cycle was carried out. Intraprocedural imaging was performed to confirm that the cryoablation ice ball enveloped the target lesion with a 5-mm margin. A postprocedure unenhanced diagnostic CT was obtained after removal of the cryoprobes to assess immediate
2.
outcomes.
Materials and methods
2.3.
Data management and statistical analysis
After approval from the institutional review board, a retrospective review of a prospective database of the medical records of patients undergoing LCA or PCA of clinically localized kidney masses at Duke University Medical Center between October 2001 and July 2008 was carried out. LCA procedures were performed by the urology department, and PCA procedures were done by the radiology department. Patients were offered cryoablation as one of the treatment options for T1 renal mass [1]. Posterior lesions were preferably considered for PCA, whereas anteromedial lesions were preferred for LCA due to their proximity to hilar structures. Patient choice and physician preferences determined the final choice between LCA and PCA. Data regarding demographics (age, gender, race, body mass index [BMI]), comorbidities, abdominal surgical history, imaging information (size, number of lesions, location [anterolateral/posterior/medial and upper/lower/interpolar]), and complications at any time during and/or following the procedure were collected.
Complications were classified as grades 1–5 according to the modified Clavien system [10]. Comorbidities were quantified using the ageadjusted Charlson Comorbidity Index (ACCI). Abdominal surgical history was classified as negative, minor (laparoscopic cholecystectomy, appendectomy, hernia repair, cesarean delivery, or tubal ligation), and major (any open abdominal surgery except appendectomy or more than two minor procedures). LCA and PCA perioperative variables and complication rates were compared using rank-sum and Fisher exact tests, as appropriate. Multivariate regression analysis was performed to assess preoperative variables that may be associated with the incidence of complications. For this analysis, all continuous variables were treated as such, including BMI, ACCI, age, and tumor size, whereas the remaining variables were used as categorical. Data are reported as median (IQR) and number (percentage) unless otherwise specified. Statistical analyses were performed using SPSS v.17 software (SPSS Inc., Chicago, IL, USA). All
2.1.
tests were two-tailed. The p values <0.05 were considered significant; p
Laparoscopic cryoablation procedure
values 0.05–0.1 were defined as trends. The LCA procedure has been described in detail previously [8]. Briefly, using a standard transperitoneal approach, the renal lesion was identified with a SSD-4000 laparoscopic ultrasound probe (Aloka Ltd, Tokyo, Japan), and the perinephric adipose tissue was excised for permanent section. One to three tissue samples of the neoplasm were taken with a 25-cm Easy Core device (Boston Scientific, Natick, MA, USA) passed through a sheath and sent for frozen section and permanent pathologic evaluation. Third-generation cryotechnology (Galil Medical, Plymouth Meeting, PA, USA) using an argon/helium gas system with 17gauge cryoneedles and thermocouples was used with a dual freeze/thaw cycle [9] under ultrasound guidance. A median of 4 (interquartile range [IQR]: 3–6) probes were used, with an additional 2 (IQR: 1–4) probes used in cases with multiple tumors. A core temperature of at least
40 8C
was reached with each freeze. In addition, we attained a 1-cm margin, if anatomically possible, beyond the tumor as visualized by intraoperative ultrasound and a temperature of at least
20 8C at the perimeter of the 1-
cm margin. FloSeal (Baxter Corp, Fremont, CA, USA) and Surgicel (Ethicon Inc, Somerville, NJ, USA) hemostatic agents were applied to assure hemostasis.
3.
Results
A total of 195 procedures (72 LCA, 123 PCA) were performed. Table 1 details the patient characteristics and comparison between the two groups. There were no significant differences in demographics. The median dominant tumor size was 2.0 (1.6–2.5 cm) in the LCA group and 2.2 (1.7–2.9 cm) in the PCA group ( p = 0.110). Complications occurred in 10 LCA patients (13.9%) and 26 PCA patients (21.1%). Classification and details are presented in Table 2. The overall complication rate was not significantly different between LCA and PCA ( p = 0.253). Of a total of 36 complications registered, 7 (overall 3.6%) were classified as severe (grade 3). No grade 5 events occurred. The distribution of the complications differed significantly between the groups with mild
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Table 1 – Patient and lesion characteristics and comparison between the groups LCA No. of patients Multiple tumors treated (%) No. of lesions Median age, yr (IQR) Gender (%) Male Female Race (%) White Other Median BMI, kg/m2 (IQR) Median ACCI (IQR) ACCI (%) 0–3 4–5 6–7 >7 Single kidney (%) Tumor location (n = 219) Anterolateral Posterior Medial Pole location (n = 219) (%) Upper Interpolar Lower Abdominal surgical history (%) Negative Minor Major Median tumor size, cm (IQR) Overall complications (%)
PCA
72 6 (8.3) 79 66 (58–63)
p value
123 12 (9.8) 140 63 (55–73)
– 0.804 – 0.385 0.640
46 (63.9) 26 (36.1)
83 (67.5) 40 (32.5)
50 (69.4) 22 (30.6) 28.5 (26.4–31.4) 4 (3–6)
90 (73.2) 33 (26.8) 28.9 (25.1–32.6) 5 (3–6)
24 28 11 9 8
38 39 35 11 7
0.622
(33.3) (38.9) (15.3) (12.5) (11.1)
(30.9) (31.7) (28.5) (8.9) (5.7)
33 (41.8) 22 (27.8) 24 (30.4)
55 (39.3) 84 (60.0) 1 (0.7)
20 (25.3) 30 (38.0) 29 (36.7)
45 (32.1) 37 (26.4) 58 (41.4)
28 (38.9) 10 (13.9) 34 (47.2) 2.0 (1.6–2.5) 10 (13.9)
37 (30.1) 31 (25.2) 55 (44.7) 2.2 (1.7–2.9) 26 (21.1)
0.617 0.377 0.181
0.177 <0.001
0.198
0.273
0.110 0.253
ACCI = age-adjusted Charlson Comorbidity Index; BMI = body mass index; IQR = interquartile range; LCA = laparoscopic cryoablation; PCA = percutaneous cryoablation.
(grades 1 and 2) complications seen more commonly in the PCA group (20.3% vs 5.6%; p = 0.001), whereas severe events (grades 3 and 4) were more frequent in the LCA group (8.3% vs 0.8%; p = 0.011). However, a large portion of these LCA complications was medical rather than surgical: postoperative myocardial infarction and two cases of cryoablation sites apparently misinterpreted as renal abscesses at outside institutions.
Additional adverse events not classifiable according to the Clavien system included one LCA converted to open due to difficult tumor localization and two PCA procedures that resulted in incomplete ablation requiring a repeat cryoablation session. Table 3 shows the multivariate analysis results to assess potential risk factors for renal cryoablation complications. Patient age and BMI were inversely associated with the
Table 2 – Complications of laparoscopic and percutaneous cryoablation classified according to the modified Clavien system Grade
LCA
1
1 atrial fibrillation 1 wound infection (managed at bedside) 2 pulmonary edema
2
–
3
2 renal/perirenal abscess (drainage) 2 urine leak (stent) 1 bleeding (nephrectomy) 1 postoperative MI – 10 (13.9)
4 5 Total (%)
PCA 12 flank pain/paresthesia 5 mild perinephric hematoma 1 postoperative hematuria (conservative management) 2 pneumothorax (conservative management) 1 nephroenteric fistula (asymptomatic, conservative management) 2 bleeding (admission and monitoring) 2 ileus (admission) 1 renal artery pseudoaneurysm (embolization)
– – 26 (21.1)
LCA = laparoscopic cryoablation; MI = myocardial infarction; PCA = percutaneous cryoablation.
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Table 3 – Multivariate logistic regression results in predicting complications after laparoscopic and percutaneous renal cryoablation Variable
p value
OR
95% CI Lower
Age, yr Female (vs male) gender BMI, kg/m2 Race (other vs white) ACCI Tumor size, cm Multiple (vs single) tumors treated LCA (vs PCA) Abdominal surgical history Negative (reference) Minor Major Tumor location* Anterolateral (reference) Medial Posterior Pole* Lower (reference) Interpolar Upper No. of probes*
0.043 0.088 0.010 0.276 0.093 0.673 0.064 0.941 0.261 – 0.450 0.103 0.122 – 0.157 0.228 0.911 – 0.866 0.753 0.559
0.960 2.278 0.889 1.627 1.252 1.105 3.312 0.965 – – 0.642 0.410 – – 0.198 1.724 – – 1.074 0.849 1.139
0.922 0.884 0.812 0.678 0.963 0.694 0.933 0.379 – – 0.203 0.141 – – 0.021 0.712 – – 0.404 0.307 0.736
Upper 0.999 5.875 0.972 3.905 1.627 1.760 11.764 2.457 – – 2.031 1.197 – – 1.865 4.176 – – 2.856 2.352 1.762
ACCI = age-adjusted Charlson Comorbidity Index; BMI = body mass index; CI = confidence interval; LCA = laparoscopic cryoablation; OR = odds ratio; PCA = percutaneous cryoablation. * Location, pole, and number of probes parameters refer to the dominant lesion.
incidence of complications (odds ratios: 0.960 and 0.884, respectively), suggesting a 40% reduction of the chance of complications for each 10 yr of age or for each 4-U increase in BMI. Of note, female gender, treatment of multiple lesions, and ACCI showed a trend ( p = 0.088, p = 0.064, and p = 0.093, respectively) toward an increased risk of complications. There was no significant association between complications and the approach chosen (LCA vs PCA), previous abdominal surgical history, or tumor location. 4.
Discussion
LCA and PCA were proposed as minimally invasive alternative treatments for renal masses that could potentially diminish morbidity and provide adequate cancer control in select patients that may not be ideal candidates for conventional surgical intervention [11,12]. To date, no study has directly addressed the complications of these ablative approaches in a single-center setting and assessed potential risk factors for these adverse events. We chose to grade the complications according to the modified Clavien system whereby grade 1 is any deviation from the normal postoperative course not requiring intervention; grade 2 complications allow for pharmacologic treatment; grade 3 is a complication that requires surgical, endoscopic, or radiological intervention; grade 4 covers a life-threatening complication; and grade 5 complications result in the patient’s death [10]. In the present study, 36 of 195 procedures (18.5%) had complications. Although overall complication rates were not significantly different between the PCA ad LCA groups, mild complications were more common in the percutaneous approach with local events such as flank pain/
paresthesia responsible for almost half (48%) of the mild complications. Severe events, in contrast, were more frequent in the LCA group (8.3%). A recent study by Laguna et al [3] examining the perioperative outcomes of LCA in 148 procedures reported similar findings with an overall complication rate of 15.5% and severe events (Clavien grade 3–5) reported in six cases (4.1%). Johnson et al [7] in their multi-institutional study found an overall renal cryoablation complication rate of 14.4% with PCA accounting for most of the complications and flank pain/ paresthesia the most common event, similar to our results. Derweesh et al [5] compared the complication profiles of 34 LCA and 26 PCA procedures. They found a comparable incidence of complications with the two approaches (14.7% and 26.9% in LCA and PCA groups, respectively). Interestingly, the authors do not report any flank pain/paresthesia events in their series, perhaps because they did not consider these events as complications. Bandi et al [4] compared the postoperative outcomes of 58 LCA and 20 PCA procedures and found no significant difference in complication rates (14% for LCA and 20% for PCA) with flank paresthesia accounting for half of the PCA complications. Similar findings were reported by Hinshaw et al [6] with 60 LCA and 30 PCA procedures. They found a 13% complication rate in the PCA group compared with 7% in LCA cases. However, in their study, major complications included atrial fibrillation, intraoperatively repaired bowel injury, and conservatively managed respiratory distress. Similarly, flank pain/paresthesia accounted for half of the PCA complications. In general, our results are in concert with the literature and suggest a higher overall incidence of complications
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EUROPEAN UROLOGY 58 (2010) 142–148
with the percutaneous approach, due to a higher incidence of mild complications that do not require surgical/ radiologic intervention or transfusions. In PCA patients, local flank complications account for half of the mild complications. This may suggest that a more careful postoperative management should be warranted with regard to pain management to reduce the incidence of these events. Although the overall complication rate was lower in the LCA group, severe events were more frequent compared with PCA. In the present series, however, there were two cases of percutaneous drainage of renal/perirenal ‘‘abscess’’ in patients after LCA. It is important to note that these treatments were performed at outside institutions where the cryoablation sites were believed to represent abscesses. In one of these cases, percutaneous drainage produced necrotic debris with sterile culture, whereas a wound infection developed subsequent to the percutaneous drainage in the other case and required surgical intervention. These cases illustrate the need for increasing awareness in the community regarding renal cryoablation as a treatment option for small renal masses and emphasize the need of familiarization with its clinical and radiographic outcomes. On multivariate analysis, adjusted for demographic and clinical variables, patient age and BMI showed an inverse association with complications. This finding suggests that older patients have a lower risk of complications. This datum, accompanied by a high prevalence of transitory flank pain complications, may be explained by the known physiologic decline in pain perception and thermal sensitivity [13,14]. Therefore, older patients may be less inclined to report pain related to the probe sites compared with younger patients with lower pain and thermal sensitivity thresholds. On multivariate analysis, a higher BMI showed a significant association with a decreased chance of complications. This may be explained by thermo-isolative properties of adipose tissue. In other words, abundant retroperitoneal fat may decrease the risk of local complications by isolating nearby structures from thermal injury induced during cryotherapy. However, in LCA, Gerota’s fascia and perirenal fat are dissected away from the treatment site, suggesting that the association between BMI found in our analyses may reflect better the PCA rather than the LCA procedures. In the present study, there was no association between the cryoablation approach (LCA/PCA) and complications. Raw data, however, suggest a higher incidence of (mainly mild) complications in PCA procedures, and this is supported by other studies [4–6], none of which attained statistical significance. Because the overall complications rate of LCA is low, larger series may be needed to delineate the complications profile of these novel techniques more accurately. The apparently higher rates of PCA complications may also be a result of the frequent finding of mild perinephric hematoma (19.2% of all PCA complications in this series) at the cryoablation site. These findings may be considered normal because no hemostatic agents are used during PCA, and some degree of perinephric bleeding may
be expected. Furthermore, these asymptomatic findings may be underreported in the LCA group because immediate postprocedure imaging is not generally performed. However, if considered a deviation from a normal postoperative course, asymptomatic perinephric hematomas may be described as grade 1 events that do not require further treatment. In this study we attempted to apply stringent criteria for the definition of postoperative complications to better depict the complications profile without underestimating the incidence. Limitations of this study deserve mention. First, the results of the current study should be interpreted in light of its retrospective nature. Second, despite being the largest LCA and PCA single-center comparison reported to date, this study was limited by sample size and therefore in statistical power. Additionally, on multivariate analysis, the predominance of PCA procedures in the cohort and the prevalence of complications in this group may have altered the applicability of the results to LCA patients. Moreover, in the LCA group the incidence of severe complications has been influenced by likely artificial iatrogenic complications whereby the cryoablation site may have been misinterpreted as an abscess and subjected to drainage. Finally, this study is a single-center cohort and the findings require validation, preferably in a large multicenter design where the risk factors for severe events may be assessed with adequate statistical power. In spite of the limitations inherent with the study design, we demonstrated the incidence of complications associated with LCA and PCA detailing their severity. The patients undergoing LCA and PCA were remarkably similar in their baseline characteristics, strengthening the interpretation of our results. This is the first study to directly address the topic of renal cryoablation complications with both the percutaneous and laparoscopic approaches providing multivariate risk factor assessment. The results of this study could be useful in counseling patients seeking cryoablative treatment and selecting appropriate candidates for this approach. 5.
Conclusions
Although percutaneous and laparoscopic renal cryoablation are considered minimally invasive, they are not without complications. These data are valuable for patient counseling. PCA may be associated with a higher rate of complications, although most of these are mild and transient. LCA may have a higher incidence of severe complications, although the incidence of severe complications in this group may have been artificially augmented by the misinterpretation of radiographic findings at outside institutions. Severe complications (Clavien grade 3 or 4) can occur in up to 3.6% of renal cryoablation patients. On multivariate analysis the chosen ablative approach (laparoscopic or percutaneous) is not associated with the risk of complications. Younger patients are at an increased risk of postoperative complications, whereas BMI plays a protective role, important for the percutaneous approach for the thermo-isolating qualities of adipose tissue.
EUROPEAN UROLOGY 58 (2010) 142–148
147
Author contributions: Thomas J. Polascik had full access to all the data in
[3] Laguna MP, Beemster P, Kumar P, et al. Perioperative morbidity of
the study and takes responsibility for the integrity of the data and the
laparoscopic cryoablation of small renal masses with ultrathin probes:
accuracy of the data analysis.
a European multicentre experience. Eur Urol 2009;56:355–62. [4] Bandi G, Hedican S, Moon T, Lee FT, Nakada SY. Comparison of
Study concept and design: Tsivian, Nelson, Polascik. Acquisition of data: Tsivian, Kim, Zilberman, Mouraviev. Analysis and interpretation of data: Tsivian, Chen, Kim. Drafting of the manuscript: Tsivian, Chen, Kim. Critical revision of the manuscript for important intellectual content: Mouraviev, Albala, Nelson, Polascik. Statistical analysis: Tsivian, Chen. Obtaining funding: None. Administrative, technical, or material support: None. Supervision: Nelson, Albala, Polascik. Other (specify): None. Financial disclosures: I certify that all conflicts of interest, including specific financial interests and relationships and affiliations relevant to the subject matter or materials discussed in the manuscript (eg,
postoperative pain, convalescence, and patient satisfaction after laparoscopic and percutaneous ablation of small renal masses. J Endourol 2008;22:963–7. [5] Derweesh IH, Malcolm JB, Diblasio CJ, et al. Single center comparison of laparoscopic cryoablation and CT-guided percutaneous cryoablation for renal tumors. J Endourol 2008;22:2461–7. [6] Hinshaw JL, Shadid AM, Nakada SY, Hedican SP, Winter TC III, Lee Jr FT. Comparison of percutaneous and laparoscopic cryoablation for the treatment of solid renal masses. AJR Am J Roentgenol 2008; 191:1159–68. [7] Johnson DB, Solomon SB, Su LM, et al. Defining the complications of cryoablation and radio frequency ablation of small renal tumors: a multi-institutional review. J Urol 2004;172:874–7. [8] Polascik TJ, Nosnik I, Mayes JM, Mouraviev V. Short term clinical
employment/ affiliation, grants or funding, consultancies, honoraria,
outcome after laparoscopic cryoablation of the renal tumor < or =
stock ownership or options, expert testimony, royalties, or patents filed,
3.5 cm. Technol Cancer Res Treat 2007;6:621–4.
received, or pending), are the following: Thomas J. Polascik received
[9] Cestari A, Guazzoni G, Naspro R, Maga T, Dell’acqua V, Rigatti P.
research support from Galil Medical. Rendon C. Nelson received research
Laparoscopic renal cryoablation (LRC) of small renal masses: lesson
support from Covidien and is a consultant for GE Healthcare. David M. Albala is a consultant for GSK and Merck and is a consultant/investor at Applied Medical.
learned after 70 procedures. Eur Urol Suppl 2006;5:220. [10] Dindo D, Demartines N, Clavien PA. Classification of surgical complications: a new proposal with evaluation in a cohort of 6336 patients and results of a survey. Ann Surg 2004;240:205–13.
Funding/Support and role of the sponsor: None.
[11] Polascik TJ, Mouraviev V. The rise of ablative technologies for treating the small renal mass. Eur Urol 2007;52:636–8. [12] Guazzoni G, Nava L, Lazzeri M, Cestari A, Volpe A, Kirkali Z. The
References
motion: cryotherapy is an efficient alternative for kidney cancer. Eur Urol 2010;57:168–70.
[1] Campbell SC, Novick AC, Belldegrun A, et al. Guideline for management of the clinical T1 renal mass. J Urol 2009;182:1271–9.
[13] Lautenbacher S, Strian F. Similarities in age differences in heat pain perception and thermal sensitivity. Funct Neurol 1991;6:129–35.
[2] Mouraviev V, Joniau S, Van Poppel H, Polascik TJ. Current status of
[14] Lariviere M, Goffaux P, Marchand S, Julien N. Changes in pain
minimally invasive ablative techniques in the treatment of small
perception and descending inhibitory controls start at middle
renal tumours. Eur Urol 2007;51:328–36.
age in healthy adults. Clin J Pain 2007;23:506–10.
Editorial Comment on: Complications of Laparoscopic and Percutaneous Renal Cryoablation in a Single Tertiary Referral Center Michael Marberger Department of Urology, Medical University of Vienna, Waehringer Guertel 18–20, A-1090 Vienna, Austria [email protected] The article by Tsivian et al on ‘‘Complications of laparoscopic and percutaneous renal cryoablation in a single tertiary referral center’’ [1] highlights some remarkable issues. The overall complication rate of laparoscopic versus percutaneous cryoablation of small renal masses is similar. This contradicts the common opinion that the percutaneous approach carries a lower morbidity, especially when performed in conscious sedation. Although there were more grade 3 and 4 complications with laparoscopic ablation, 30.4% of the masses treated in this manner were in a medial position. Only 0.7% of the masses treated percutaneously had this location, obviously because the proximity of vulnerable hilar structures was
considered to render this approach riskier. This implies that laparoscopic cryoablation provides more flexibility in difficult situations at no higher risk of complications. The authors provide no data on follow-up or oncologic outcome, but two patients managed percutaneously required retreatment because of incomplete ablation. Although cryoablation appears to provide more reliable tissue destruction than radiofrequency ablation [2,3], the percutaneous approach has been reported to consistently have higher retreatment rates than laparoscopic techniques [3]. Apparently cryoprobes can be positioned more precisely under direct vision and simultaneous laparoscopic ultrasonography than they can percutaneously with cross-sectional imaging. A major advantage of the former technique is the possibility of stabilizing the target mechanically at the time of puncture. Laparoscopic and percutaneous cryoablation, although minimally invasive, have significant complication rates, with up to 3.4% grade 3 or 4 events. This is definitely lower than for open or laparoscopic nephron-sparing excision [4], but the higher residual/recurrent tumor rates after cryoablation weigh in heavily in the choice of therapy for
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healthy, younger patients. Energy-ablative therapy has therefore traditionally been reserved for elderly, infirm patients. Given the low aggressive potential of many renal masses of this size, active surveillance is becoming an attractive alternative in this patient group, certainly providing lower complication rates.
[2] Weight CJ, Kaouk JH, Hegarty NJ. Correlation of radiographic imaging and histopathology following cryoablation and radio frequency ablation for renal tumors. J Urol 2008;179:1277–83. [3] Campbell SC, Novick AC, Belldegrun A, et al. Guideline for management of the clinical T1 renal mass. J Urol 2009;182:1271–9. [4] Lane BR, Novick AC, Babineau D, Fergany AF, Kaouk JH, Gill IS. Comparison of laparoscopic and open partial nephrectomy for tumor in a solitary kidney. J Urol 2008;179:847–52
References [1] Tsivian M, Chen VH, Kim CY, et al. Complications of laparoscopic
DOI: 10.1016/j.eururo.2010.03.040
and percutaneous renal cryoablation in a single tertiary referral center. Eur Urol 2010;58:142–8.
DOI of original article: 10.1016/j.eururo.2010.03.035
available at www.sciencedirect.com journal homepage: www.europeanurology.com
Endo-urology
Complications of Laparoscopic and Percutaneous Renal Cryoablation in a Single Tertiary Referral Center Matvey Tsivian a, Valerie H. Chen a, Charles Y. Kim b, Dorit E. Zilberman a, Vladimir Mouraviev a, Rendon C. Nelson b, David M. Albala a, Thomas J. Polascik a,* a
Division of Urology, Department of Surgery, Duke University Medical Center, Durham, NC, USA
b
Department of Radiology, Duke University Medical Center, Durham, NC, USA
Article info
Abstract
Article history: Accepted March 19, 2010 Published online ahead of print on March 30, 2010
Background: Laparoscopic cryoablation (LCA) and percutaneous cryoablation (PCA) of small renal masses have gained popularity, but only limited data exist on the complication rates. Objectives: In this study, we report on postoperative complications associated with LCA and PCA in a single tertiary center experience. Design, setting, and participants: We conducted a retrospective review of electronic medical records for patients undergoing LCA or PCA between 2001 and 2008 at our institution. Interventions: All patients underwent LCA or PCA. Measurements: Demographics, radiographic variables, and complication rates were compared between the two groups. Complications were classified according to the modified Clavien system. Results and limitations: Of a total of 195 patients included in this study, 72 underwent LCA and 123 underwent PCA. There were no differences in demographics between the groups. We observed complications in 10 LCA procedures (13.9%) and 26 PCA procedures (21.1%) ( p = 0.253). The distribution of the complications differed significantly between the groups with mild complications (grades 1 and 2) more common in the PCA group (20.3% vs 5.6%, respectively; p = 0.001), whereas severe events (grades 3 and 4) were more frequent in the LCA group (8.3% vs 0.8%, respectively; p = 0.011). On multivariate analysis, age and body mass index were inversely associated with complications, whereas female gender, multiple tumors, and preexisting comorbidities showed a trend toward increased risk. Conclusions: LCA and PCA, although minimally invasive, are not void of complications. Most of the complications encountered are mild; however, severe (grade 3 or 4) events may occur in up to 3.6% of patients. PCA may be associated with a higher rate of complications, although most of these are mild and transient. However, on multivariate analysis, the chosen ablative approach (laparoscopic or percutaneous) is not associated with the risk of complications.
Keywords: Complications Cryoablation Laparoscopic Percutaneous Renal neoplasm
# 2010 European Association of Urology. Published by Elsevier B.V. All rights reserved. * Corresponding author. Duke University Medical Center, Box 2804, Yellow Zone, Durham, NC 27710, USA. Tel. +1 919 684 4946; Fax: +1 919 684 5220. E-mail address: [email protected] (T.J. Polascik). 0302-2838/$ – see back matter # 2010 European Association of Urology. Published by Elsevier B.V. All rights reserved.
doi:10.1016/j.eururo.2010.03.035
EUROPEAN UROLOGY 58 (2010) 142–148
1.
2.2.
Introduction
The extensive use of computed tomography (CT) and magnetic resonance imaging has brought about a concomitant increase in the incidental detection of small renal masses. The current standard of care is surgical resection; however, alternative approaches such as cryoablation have been accepted as a viable treatment option for localized renal masses in appropriate candidates [1]. Laparoscopic cryoablation (LCA) and percutaneous cryoablation (PCA) are gaining popularity as an alternative to conventional surgery for their minimally invasive nature and good oncologic outcomes [2]. The minimally invasive nature, however, does not necessarily translate to a lower complication rate. Only scattered reports are available in the literature regarding the complications of these procedures, especially in a comparative fashion in an academic referral center [3–7]. In this paper we report on the complications associated with LCA and PCA in a single tertiary-center experience.
143
Percutaneous cryoablation procedure
All PCA procedures performed since 2005 have used low-resolution and low-mA CT-fluoroscopy for guidance. The patient was placed in a prone or decubitus position based on the location of the lesion. A radiopaque strip was placed on the flank, and a diagnostic CT was performed to identify the lesions and plan the probe insertion paths. Contrastenhanced images were obtained if the lesion could not be definitely identified with noncontrast images. The flank was draped and prepped and the probe entry site anaesthetized with 1% lidocaine. Under moderate conscious sedation, the skin was punctured with a scalpel at the entry site. If the lesion was in close proximity to a vulnerable structure such as the bowel, hydrodissection was performed by infusion of normal saline (n = 16; 13%). A 14-gauge cryoprobe (Endocare, Irvine, CA, USA) was advanced into the lesion and held in place with a short freeze. Additional probes, if needed, were positioned in a similar fashion. A median of 2 (IQR: 1–3) probes were used, with an additional 2 (IQR: 1– 3) probes used in cases with multiple tumors. After verification of correct positioning of the probes, a standard 10-min freeze/8-min thaw/10-min freeze/final thaw cycle was carried out. Intraprocedural imaging was performed to confirm that the cryoablation ice ball enveloped the target lesion with a 5-mm margin. A postprocedure unenhanced diagnostic CT was obtained after removal of the cryoprobes to assess immediate
2.
outcomes.
Materials and methods
2.3.
Data management and statistical analysis
After approval from the institutional review board, a retrospective review of a prospective database of the medical records of patients undergoing LCA or PCA of clinically localized kidney masses at Duke University Medical Center between October 2001 and July 2008 was carried out. LCA procedures were performed by the urology department, and PCA procedures were done by the radiology department. Patients were offered cryoablation as one of the treatment options for T1 renal mass [1]. Posterior lesions were preferably considered for PCA, whereas anteromedial lesions were preferred for LCA due to their proximity to hilar structures. Patient choice and physician preferences determined the final choice between LCA and PCA. Data regarding demographics (age, gender, race, body mass index [BMI]), comorbidities, abdominal surgical history, imaging information (size, number of lesions, location [anterolateral/posterior/medial and upper/lower/interpolar]), and complications at any time during and/or following the procedure were collected.
Complications were classified as grades 1–5 according to the modified Clavien system [10]. Comorbidities were quantified using the ageadjusted Charlson Comorbidity Index (ACCI). Abdominal surgical history was classified as negative, minor (laparoscopic cholecystectomy, appendectomy, hernia repair, cesarean delivery, or tubal ligation), and major (any open abdominal surgery except appendectomy or more than two minor procedures). LCA and PCA perioperative variables and complication rates were compared using rank-sum and Fisher exact tests, as appropriate. Multivariate regression analysis was performed to assess preoperative variables that may be associated with the incidence of complications. For this analysis, all continuous variables were treated as such, including BMI, ACCI, age, and tumor size, whereas the remaining variables were used as categorical. Data are reported as median (IQR) and number (percentage) unless otherwise specified. Statistical analyses were performed using SPSS v.17 software (SPSS Inc., Chicago, IL, USA). All
2.1.
tests were two-tailed. The p values <0.05 were considered significant; p
Laparoscopic cryoablation procedure
values 0.05–0.1 were defined as trends. The LCA procedure has been described in detail previously [8]. Briefly, using a standard transperitoneal approach, the renal lesion was identified with a SSD-4000 laparoscopic ultrasound probe (Aloka Ltd, Tokyo, Japan), and the perinephric adipose tissue was excised for permanent section. One to three tissue samples of the neoplasm were taken with a 25-cm Easy Core device (Boston Scientific, Natick, MA, USA) passed through a sheath and sent for frozen section and permanent pathologic evaluation. Third-generation cryotechnology (Galil Medical, Plymouth Meeting, PA, USA) using an argon/helium gas system with 17gauge cryoneedles and thermocouples was used with a dual freeze/thaw cycle [9] under ultrasound guidance. A median of 4 (interquartile range [IQR]: 3–6) probes were used, with an additional 2 (IQR: 1–4) probes used in cases with multiple tumors. A core temperature of at least
40 8C
was reached with each freeze. In addition, we attained a 1-cm margin, if anatomically possible, beyond the tumor as visualized by intraoperative ultrasound and a temperature of at least
20 8C at the perimeter of the 1-
cm margin. FloSeal (Baxter Corp, Fremont, CA, USA) and Surgicel (Ethicon Inc, Somerville, NJ, USA) hemostatic agents were applied to assure hemostasis.
3.
Results
A total of 195 procedures (72 LCA, 123 PCA) were performed. Table 1 details the patient characteristics and comparison between the two groups. There were no significant differences in demographics. The median dominant tumor size was 2.0 (1.6–2.5 cm) in the LCA group and 2.2 (1.7–2.9 cm) in the PCA group ( p = 0.110). Complications occurred in 10 LCA patients (13.9%) and 26 PCA patients (21.1%). Classification and details are presented in Table 2. The overall complication rate was not significantly different between LCA and PCA ( p = 0.253). Of a total of 36 complications registered, 7 (overall 3.6%) were classified as severe (grade 3). No grade 5 events occurred. The distribution of the complications differed significantly between the groups with mild
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Table 1 – Patient and lesion characteristics and comparison between the groups LCA No. of patients Multiple tumors treated (%) No. of lesions Median age, yr (IQR) Gender (%) Male Female Race (%) White Other Median BMI, kg/m2 (IQR) Median ACCI (IQR) ACCI (%) 0–3 4–5 6–7 >7 Single kidney (%) Tumor location (n = 219) Anterolateral Posterior Medial Pole location (n = 219) (%) Upper Interpolar Lower Abdominal surgical history (%) Negative Minor Major Median tumor size, cm (IQR) Overall complications (%)
PCA
72 6 (8.3) 79 66 (58–63)
p value
123 12 (9.8) 140 63 (55–73)
– 0.804 – 0.385 0.640
46 (63.9) 26 (36.1)
83 (67.5) 40 (32.5)
50 (69.4) 22 (30.6) 28.5 (26.4–31.4) 4 (3–6)
90 (73.2) 33 (26.8) 28.9 (25.1–32.6) 5 (3–6)
24 28 11 9 8
38 39 35 11 7
0.622
(33.3) (38.9) (15.3) (12.5) (11.1)
(30.9) (31.7) (28.5) (8.9) (5.7)
33 (41.8) 22 (27.8) 24 (30.4)
55 (39.3) 84 (60.0) 1 (0.7)
20 (25.3) 30 (38.0) 29 (36.7)
45 (32.1) 37 (26.4) 58 (41.4)
28 (38.9) 10 (13.9) 34 (47.2) 2.0 (1.6–2.5) 10 (13.9)
37 (30.1) 31 (25.2) 55 (44.7) 2.2 (1.7–2.9) 26 (21.1)
0.617 0.377 0.181
0.177 <0.001
0.198
0.273
0.110 0.253
ACCI = age-adjusted Charlson Comorbidity Index; BMI = body mass index; IQR = interquartile range; LCA = laparoscopic cryoablation; PCA = percutaneous cryoablation.
(grades 1 and 2) complications seen more commonly in the PCA group (20.3% vs 5.6%; p = 0.001), whereas severe events (grades 3 and 4) were more frequent in the LCA group (8.3% vs 0.8%; p = 0.011). However, a large portion of these LCA complications was medical rather than surgical: postoperative myocardial infarction and two cases of cryoablation sites apparently misinterpreted as renal abscesses at outside institutions.
Additional adverse events not classifiable according to the Clavien system included one LCA converted to open due to difficult tumor localization and two PCA procedures that resulted in incomplete ablation requiring a repeat cryoablation session. Table 3 shows the multivariate analysis results to assess potential risk factors for renal cryoablation complications. Patient age and BMI were inversely associated with the
Table 2 – Complications of laparoscopic and percutaneous cryoablation classified according to the modified Clavien system Grade
LCA
1
1 atrial fibrillation 1 wound infection (managed at bedside) 2 pulmonary edema
2
–
3
2 renal/perirenal abscess (drainage) 2 urine leak (stent) 1 bleeding (nephrectomy) 1 postoperative MI – 10 (13.9)
4 5 Total (%)
PCA 12 flank pain/paresthesia 5 mild perinephric hematoma 1 postoperative hematuria (conservative management) 2 pneumothorax (conservative management) 1 nephroenteric fistula (asymptomatic, conservative management) 2 bleeding (admission and monitoring) 2 ileus (admission) 1 renal artery pseudoaneurysm (embolization)
– – 26 (21.1)
LCA = laparoscopic cryoablation; MI = myocardial infarction; PCA = percutaneous cryoablation.
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Table 3 – Multivariate logistic regression results in predicting complications after laparoscopic and percutaneous renal cryoablation Variable
p value
OR
95% CI Lower
Age, yr Female (vs male) gender BMI, kg/m2 Race (other vs white) ACCI Tumor size, cm Multiple (vs single) tumors treated LCA (vs PCA) Abdominal surgical history Negative (reference) Minor Major Tumor location* Anterolateral (reference) Medial Posterior Pole* Lower (reference) Interpolar Upper No. of probes*
0.043 0.088 0.010 0.276 0.093 0.673 0.064 0.941 0.261 – 0.450 0.103 0.122 – 0.157 0.228 0.911 – 0.866 0.753 0.559
0.960 2.278 0.889 1.627 1.252 1.105 3.312 0.965 – – 0.642 0.410 – – 0.198 1.724 – – 1.074 0.849 1.139
0.922 0.884 0.812 0.678 0.963 0.694 0.933 0.379 – – 0.203 0.141 – – 0.021 0.712 – – 0.404 0.307 0.736
Upper 0.999 5.875 0.972 3.905 1.627 1.760 11.764 2.457 – – 2.031 1.197 – – 1.865 4.176 – – 2.856 2.352 1.762
ACCI = age-adjusted Charlson Comorbidity Index; BMI = body mass index; CI = confidence interval; LCA = laparoscopic cryoablation; OR = odds ratio; PCA = percutaneous cryoablation. * Location, pole, and number of probes parameters refer to the dominant lesion.
incidence of complications (odds ratios: 0.960 and 0.884, respectively), suggesting a 40% reduction of the chance of complications for each 10 yr of age or for each 4-U increase in BMI. Of note, female gender, treatment of multiple lesions, and ACCI showed a trend ( p = 0.088, p = 0.064, and p = 0.093, respectively) toward an increased risk of complications. There was no significant association between complications and the approach chosen (LCA vs PCA), previous abdominal surgical history, or tumor location. 4.
Discussion
LCA and PCA were proposed as minimally invasive alternative treatments for renal masses that could potentially diminish morbidity and provide adequate cancer control in select patients that may not be ideal candidates for conventional surgical intervention [11,12]. To date, no study has directly addressed the complications of these ablative approaches in a single-center setting and assessed potential risk factors for these adverse events. We chose to grade the complications according to the modified Clavien system whereby grade 1 is any deviation from the normal postoperative course not requiring intervention; grade 2 complications allow for pharmacologic treatment; grade 3 is a complication that requires surgical, endoscopic, or radiological intervention; grade 4 covers a life-threatening complication; and grade 5 complications result in the patient’s death [10]. In the present study, 36 of 195 procedures (18.5%) had complications. Although overall complication rates were not significantly different between the PCA ad LCA groups, mild complications were more common in the percutaneous approach with local events such as flank pain/
paresthesia responsible for almost half (48%) of the mild complications. Severe events, in contrast, were more frequent in the LCA group (8.3%). A recent study by Laguna et al [3] examining the perioperative outcomes of LCA in 148 procedures reported similar findings with an overall complication rate of 15.5% and severe events (Clavien grade 3–5) reported in six cases (4.1%). Johnson et al [7] in their multi-institutional study found an overall renal cryoablation complication rate of 14.4% with PCA accounting for most of the complications and flank pain/ paresthesia the most common event, similar to our results. Derweesh et al [5] compared the complication profiles of 34 LCA and 26 PCA procedures. They found a comparable incidence of complications with the two approaches (14.7% and 26.9% in LCA and PCA groups, respectively). Interestingly, the authors do not report any flank pain/paresthesia events in their series, perhaps because they did not consider these events as complications. Bandi et al [4] compared the postoperative outcomes of 58 LCA and 20 PCA procedures and found no significant difference in complication rates (14% for LCA and 20% for PCA) with flank paresthesia accounting for half of the PCA complications. Similar findings were reported by Hinshaw et al [6] with 60 LCA and 30 PCA procedures. They found a 13% complication rate in the PCA group compared with 7% in LCA cases. However, in their study, major complications included atrial fibrillation, intraoperatively repaired bowel injury, and conservatively managed respiratory distress. Similarly, flank pain/paresthesia accounted for half of the PCA complications. In general, our results are in concert with the literature and suggest a higher overall incidence of complications
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EUROPEAN UROLOGY 58 (2010) 142–148
with the percutaneous approach, due to a higher incidence of mild complications that do not require surgical/ radiologic intervention or transfusions. In PCA patients, local flank complications account for half of the mild complications. This may suggest that a more careful postoperative management should be warranted with regard to pain management to reduce the incidence of these events. Although the overall complication rate was lower in the LCA group, severe events were more frequent compared with PCA. In the present series, however, there were two cases of percutaneous drainage of renal/perirenal ‘‘abscess’’ in patients after LCA. It is important to note that these treatments were performed at outside institutions where the cryoablation sites were believed to represent abscesses. In one of these cases, percutaneous drainage produced necrotic debris with sterile culture, whereas a wound infection developed subsequent to the percutaneous drainage in the other case and required surgical intervention. These cases illustrate the need for increasing awareness in the community regarding renal cryoablation as a treatment option for small renal masses and emphasize the need of familiarization with its clinical and radiographic outcomes. On multivariate analysis, adjusted for demographic and clinical variables, patient age and BMI showed an inverse association with complications. This finding suggests that older patients have a lower risk of complications. This datum, accompanied by a high prevalence of transitory flank pain complications, may be explained by the known physiologic decline in pain perception and thermal sensitivity [13,14]. Therefore, older patients may be less inclined to report pain related to the probe sites compared with younger patients with lower pain and thermal sensitivity thresholds. On multivariate analysis, a higher BMI showed a significant association with a decreased chance of complications. This may be explained by thermo-isolative properties of adipose tissue. In other words, abundant retroperitoneal fat may decrease the risk of local complications by isolating nearby structures from thermal injury induced during cryotherapy. However, in LCA, Gerota’s fascia and perirenal fat are dissected away from the treatment site, suggesting that the association between BMI found in our analyses may reflect better the PCA rather than the LCA procedures. In the present study, there was no association between the cryoablation approach (LCA/PCA) and complications. Raw data, however, suggest a higher incidence of (mainly mild) complications in PCA procedures, and this is supported by other studies [4–6], none of which attained statistical significance. Because the overall complications rate of LCA is low, larger series may be needed to delineate the complications profile of these novel techniques more accurately. The apparently higher rates of PCA complications may also be a result of the frequent finding of mild perinephric hematoma (19.2% of all PCA complications in this series) at the cryoablation site. These findings may be considered normal because no hemostatic agents are used during PCA, and some degree of perinephric bleeding may
be expected. Furthermore, these asymptomatic findings may be underreported in the LCA group because immediate postprocedure imaging is not generally performed. However, if considered a deviation from a normal postoperative course, asymptomatic perinephric hematomas may be described as grade 1 events that do not require further treatment. In this study we attempted to apply stringent criteria for the definition of postoperative complications to better depict the complications profile without underestimating the incidence. Limitations of this study deserve mention. First, the results of the current study should be interpreted in light of its retrospective nature. Second, despite being the largest LCA and PCA single-center comparison reported to date, this study was limited by sample size and therefore in statistical power. Additionally, on multivariate analysis, the predominance of PCA procedures in the cohort and the prevalence of complications in this group may have altered the applicability of the results to LCA patients. Moreover, in the LCA group the incidence of severe complications has been influenced by likely artificial iatrogenic complications whereby the cryoablation site may have been misinterpreted as an abscess and subjected to drainage. Finally, this study is a single-center cohort and the findings require validation, preferably in a large multicenter design where the risk factors for severe events may be assessed with adequate statistical power. In spite of the limitations inherent with the study design, we demonstrated the incidence of complications associated with LCA and PCA detailing their severity. The patients undergoing LCA and PCA were remarkably similar in their baseline characteristics, strengthening the interpretation of our results. This is the first study to directly address the topic of renal cryoablation complications with both the percutaneous and laparoscopic approaches providing multivariate risk factor assessment. The results of this study could be useful in counseling patients seeking cryoablative treatment and selecting appropriate candidates for this approach. 5.
Conclusions
Although percutaneous and laparoscopic renal cryoablation are considered minimally invasive, they are not without complications. These data are valuable for patient counseling. PCA may be associated with a higher rate of complications, although most of these are mild and transient. LCA may have a higher incidence of severe complications, although the incidence of severe complications in this group may have been artificially augmented by the misinterpretation of radiographic findings at outside institutions. Severe complications (Clavien grade 3 or 4) can occur in up to 3.6% of renal cryoablation patients. On multivariate analysis the chosen ablative approach (laparoscopic or percutaneous) is not associated with the risk of complications. Younger patients are at an increased risk of postoperative complications, whereas BMI plays a protective role, important for the percutaneous approach for the thermo-isolating qualities of adipose tissue.
EUROPEAN UROLOGY 58 (2010) 142–148
147
Author contributions: Thomas J. Polascik had full access to all the data in
[3] Laguna MP, Beemster P, Kumar P, et al. Perioperative morbidity of
the study and takes responsibility for the integrity of the data and the
laparoscopic cryoablation of small renal masses with ultrathin probes:
accuracy of the data analysis.
a European multicentre experience. Eur Urol 2009;56:355–62. [4] Bandi G, Hedican S, Moon T, Lee FT, Nakada SY. Comparison of
Study concept and design: Tsivian, Nelson, Polascik. Acquisition of data: Tsivian, Kim, Zilberman, Mouraviev. Analysis and interpretation of data: Tsivian, Chen, Kim. Drafting of the manuscript: Tsivian, Chen, Kim. Critical revision of the manuscript for important intellectual content: Mouraviev, Albala, Nelson, Polascik. Statistical analysis: Tsivian, Chen. Obtaining funding: None. Administrative, technical, or material support: None. Supervision: Nelson, Albala, Polascik. Other (specify): None. Financial disclosures: I certify that all conflicts of interest, including specific financial interests and relationships and affiliations relevant to the subject matter or materials discussed in the manuscript (eg,
postoperative pain, convalescence, and patient satisfaction after laparoscopic and percutaneous ablation of small renal masses. J Endourol 2008;22:963–7. [5] Derweesh IH, Malcolm JB, Diblasio CJ, et al. Single center comparison of laparoscopic cryoablation and CT-guided percutaneous cryoablation for renal tumors. J Endourol 2008;22:2461–7. [6] Hinshaw JL, Shadid AM, Nakada SY, Hedican SP, Winter TC III, Lee Jr FT. Comparison of percutaneous and laparoscopic cryoablation for the treatment of solid renal masses. AJR Am J Roentgenol 2008; 191:1159–68. [7] Johnson DB, Solomon SB, Su LM, et al. Defining the complications of cryoablation and radio frequency ablation of small renal tumors: a multi-institutional review. J Urol 2004;172:874–7. [8] Polascik TJ, Nosnik I, Mayes JM, Mouraviev V. Short term clinical
employment/ affiliation, grants or funding, consultancies, honoraria,
outcome after laparoscopic cryoablation of the renal tumor < or =
stock ownership or options, expert testimony, royalties, or patents filed,
3.5 cm. Technol Cancer Res Treat 2007;6:621–4.
received, or pending), are the following: Thomas J. Polascik received
[9] Cestari A, Guazzoni G, Naspro R, Maga T, Dell’acqua V, Rigatti P.
research support from Galil Medical. Rendon C. Nelson received research
Laparoscopic renal cryoablation (LRC) of small renal masses: lesson
support from Covidien and is a consultant for GE Healthcare. David M. Albala is a consultant for GSK and Merck and is a consultant/investor at Applied Medical.
learned after 70 procedures. Eur Urol Suppl 2006;5:220. [10] Dindo D, Demartines N, Clavien PA. Classification of surgical complications: a new proposal with evaluation in a cohort of 6336 patients and results of a survey. Ann Surg 2004;240:205–13.
Funding/Support and role of the sponsor: None.
[11] Polascik TJ, Mouraviev V. The rise of ablative technologies for treating the small renal mass. Eur Urol 2007;52:636–8. [12] Guazzoni G, Nava L, Lazzeri M, Cestari A, Volpe A, Kirkali Z. The
References
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Editorial Comment on: Complications of Laparoscopic and Percutaneous Renal Cryoablation in a Single Tertiary Referral Center Michael Marberger Department of Urology, Medical University of Vienna, Waehringer Guertel 18–20, A-1090 Vienna, Austria [email protected] The article by Tsivian et al on ‘‘Complications of laparoscopic and percutaneous renal cryoablation in a single tertiary referral center’’ [1] highlights some remarkable issues. The overall complication rate of laparoscopic versus percutaneous cryoablation of small renal masses is similar. This contradicts the common opinion that the percutaneous approach carries a lower morbidity, especially when performed in conscious sedation. Although there were more grade 3 and 4 complications with laparoscopic ablation, 30.4% of the masses treated in this manner were in a medial position. Only 0.7% of the masses treated percutaneously had this location, obviously because the proximity of vulnerable hilar structures was
considered to render this approach riskier. This implies that laparoscopic cryoablation provides more flexibility in difficult situations at no higher risk of complications. The authors provide no data on follow-up or oncologic outcome, but two patients managed percutaneously required retreatment because of incomplete ablation. Although cryoablation appears to provide more reliable tissue destruction than radiofrequency ablation [2,3], the percutaneous approach has been reported to consistently have higher retreatment rates than laparoscopic techniques [3]. Apparently cryoprobes can be positioned more precisely under direct vision and simultaneous laparoscopic ultrasonography than they can percutaneously with cross-sectional imaging. A major advantage of the former technique is the possibility of stabilizing the target mechanically at the time of puncture. Laparoscopic and percutaneous cryoablation, although minimally invasive, have significant complication rates, with up to 3.4% grade 3 or 4 events. This is definitely lower than for open or laparoscopic nephron-sparing excision [4], but the higher residual/recurrent tumor rates after cryoablation weigh in heavily in the choice of therapy for
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healthy, younger patients. Energy-ablative therapy has therefore traditionally been reserved for elderly, infirm patients. Given the low aggressive potential of many renal masses of this size, active surveillance is becoming an attractive alternative in this patient group, certainly providing lower complication rates.
[2] Weight CJ, Kaouk JH, Hegarty NJ. Correlation of radiographic imaging and histopathology following cryoablation and radio frequency ablation for renal tumors. J Urol 2008;179:1277–83. [3] Campbell SC, Novick AC, Belldegrun A, et al. Guideline for management of the clinical T1 renal mass. J Urol 2009;182:1271–9. [4] Lane BR, Novick AC, Babineau D, Fergany AF, Kaouk JH, Gill IS. Comparison of laparoscopic and open partial nephrectomy for tumor in a solitary kidney. J Urol 2008;179:847–52
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DOI: 10.1016/j.eururo.2010.03.040
and percutaneous renal cryoablation in a single tertiary referral center. Eur Urol 2010;58:142–8.
DOI of original article: 10.1016/j.eururo.2010.03.035