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Silvestri et al. Mini-invasive Surg 2019;3:5 I http://dx.doi.org/10.20517/2574-1225.2018.67 Page 3 of 11

[21]
Hence, the main disadvantages of LCA are : (1) general anesthesia is required (it is not an outpatient
procedure); (2) a higher rate of complication in comparison to PCA; (3) less rate of pain control and worst
cosmetic in comparison to PCA; (4) higher cost rate in comparison to PCA.

PATIENT SELECTION AND INDICATION FOR LCA
The indications for LCA procedure are the same of all ablative techniques and limited to patients with
contraindications to surgical extirpative therapy for comorbidities, advanced age, imperative indications for
[1]
NSS or have a strong preference for nonsurgical management .

Currently, the 2017 AUA guidelines recommend consideration of ablation as an alternative to PN for cT1a
[12]
renal lesions less than 3 cm in size . Otherwise, the European Association of Urology guidelines do not
[1]
recommend an upper limit of diameter . Today there are data supporting CA for cT1b lesions, but in view
[22]
of higher recurrence rate and complications should be reserved for patients with imperative indications .
The location of the mass is a major factor in determining if the mass should be ablated laparoscopically or
percutaneously, but the most important factor is the surgeons’ experience.

PROCEDURE AND TECHNIQUES
A transperitoneal approach is generally used for anterior and anteromedial tumors, whereas a retroperitoneal
approach permits access to posterior and posterolateral tumors [23,24] .

Effective cryosurgical tissue injury depends on: (1) excellent monitoring of the process; (2) fast cooling to a
lethal temperature; (3) slow thawing; (4) repetition of the freeze-thaw cycle (2 times); (5) freeze cycle length
of 8-10 min is commonplace in literature; (6) thaw cycle at least 5-8 min.

Critical factors of the procedure are: (1) placement of the cryoneedles; (2) reach and center a lethal
temperature in the central part of the lesion with an ice ball margin of at least 5 mm to avoid a residual or an
[25]
untreated tumor ; (3) iceball imaging as mentioned above.

Key factors to obtain specific success of LCA: (1) take your time to make a better exposure of the renal lesion:
the real key is finding the better position for the cryoneedles; (2) triangle disposition of the cryoneedles
by putting the different probes at least 10 mm of distance each other; (3) the using of hemostatic agents to
prevent or treat bleeding; (4) high experience of the surgeon in NSS: in some rare case, it could be necessary
to put sutures.

The number and size of the cryoprobes placed depends on the size and configuration of the mass. Generally,
one probe is needed for each centimeter of tumor diameter to be treated. Recently, the use of multiple
smaller probe has increased the variety and size of tumors that can be treated. When mobilization of the
kidney is feasible, US probes are placed on the contralateral side of the kidney for visualization. Attention
should be reserved for relative warming of the ablation zone by large central vessels: the thermal sink effect
might be a limit to achieve the lethal temperature.

Laparoscopic cryoablation
Pneumoperitoneum and trocars placement
General anesthesia is required. The patient is placed in a standard flank position. Pneumoperitoneum
is usually achieved in two ways: using the open Hasson technique or by placing a Veress needle in the
umbilicus of the patient who have not had previous abdominal surgery or in the upper quadrant (left