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Carilli et al. Mini-invasive Surg 2024;8:9 https://dx.doi.org/10.20517/2574-1225.2023.132 Page 5 of 7

The clamping of renal pedicle has been described as an independent predictor of immediate and early renal
[19]
[18]
function impairment after partial nephrectomy . This led to the development of the off-clamp RAPN .
However, randomised clinical trials comparing on-clamp vs. off-clamp RAPN have shown minimal impact
of ischaemia on functional recovery. On the other hand, the two techniques demonstrated similar blood loss
and complication rates [20-22] .

On these bases, the question arises spontaneously: in light of the aforementioned results, why an off-clamp
approach should be adopted? We herein provide some considerations. First, the cited results concern
procedures performed for single renal tumours, with limited ischemia intervals (averaging 15-20 min).

The lack of trials specific of the setting of multiple ipsilateral tumours prevents us from drawing definitive
conclusions on which is the more appropriate approach. Overall, our institutional experience led us to opt
for an off-clamp technique whenever possible. While the benefit from this approach can be debated in the
setting of bilateral kidney, normal renal function, and single localised tumour, we believe that the off-clamp
approach is a good indication in the management of multiple ipsilateral tumours.

Given the consistent experience matured also in the setting of pure laparoscopy [23,24] , our philosophy is even
more extreme in this setting. Beyond the off-clamp approach, we believe that an “off-renal-hilum-
dissection” approach is key here. As such, if the avoidance of the 30-40 min of ischemia may not translate
into any clinically relevant advantage in terms of renal function, we believe that leaving the hilum not
dissected is a plus. This is particularly important given the non-negligible risk of re-doing partial
nephrectomy in patients with multiple ipsilateral tumours, who, in many cases, live in the context of genetic
syndromes. Some reports about re-doing partial nephrectomy have underlined this is a technically
demanding procedure due to adhesions both at the level of the previously dissected hilum and at the level of
[25]
the Gerota’s fascia .

When performing off-clamp RAPN, another important point is to pair it with an anatomical tumour
excision . Recent literature has shown that the amount of healthy parenchyma preserved during the
[7]
procedure is a major predictive factor for post-operative renal function recovery, both during tumour
excision and renorrhaphy [6,26,27] . Accordingly, most of the tumour lesions in this case series were managed by
a pure enucleation (71%) followed by a single-layer sliding-clip renorrhaphy (61%): this approach is
[28]
essential in the multiple ipsilateral tumours, in order to perform a “true” nephron-sparing surgery .

Our results were comparable with those reported in literature. In a recent retrospective multicentre study on
61 patients affected by multiple ipsilateral tumours, RAPN (regardless of vascular hilar management)
showed an overall post-operative complication rate of 23% (2 cases Clavien-Dindo grade > 2), and positive
surgical margins rate of 6.5% . In another single-centre retrospective study on 50 patients affected by
[16]
multiple ipsilateral tumours, after a propensity score matching based on age, CCI, tumour size and
nephrometric score vs. patients with a single tumour undergoing RAPN, no statistically significant
difference was found in terms of eGFR (-6.4% in the multiple tumours group) or post-operative
[17]
complications Clavien-Dindo grade ≥ 2 (10.2% in the multiple tumours group) .

We acknowledge the limitations of the study. First, the retrospective nature of the study, and the lack of a
control group; Second, the limited sample size. Last, the short-term follow-up prevents us from any
meaningful conclusion in terms of durability of oncological and functional outcomes.