Leaving out the renorrhaphy held up, with a caveat about fistulae

Design

single-centre, single-surgeon randomised controlled non-inferiority trial (margin −10%)

Population

248 patients with cT1-2N0M0 renal tumours

Primary outcome

Trifecta achievement at discharge

Effect

93% versus 95%, absolute difference −2.4% (90% CI −7.4 to 2.6), non-inferiority met (one-sided p=0.006); 9 urinary fistulae overall, higher in the sutureless arm (p=0.08)

Two hundred and forty-eight patients with cT1-2N0M0 renal tumours were randomised, within a single-centre single-surgeon trial, to sutureless or renorrhaphy purely off-clamp robotic partial nephrectomy, with covariate-adaptive randomisation balancing age, sex, baseline renal function and tumour complexity. The primary endpoint was Trifecta achievement at discharge, tested for non-inferiority against a margin of −10%.

Trifecta was reached in 93% of sutureless cases and 95% of renorrhaphy cases, absolute difference −2.4% (90% CI −7.4 to 2.6), meeting non-inferiority (one-sided p=0.006). Transfusion was rare (2.4% against 0%) and acute kidney injury occurred in 1.6% of both arms. Nine urinary fistulae occurred across the whole trial, all managed with temporary stenting, with a higher rate in the sutureless arm that did not reach significance (p=0.08). Renal function was stable to 12 months, and one-year recurrence-free survival was 99% in both arms.

The rationale for omitting renorrhaphy is that suturing the parenchyma sacrifices functional tissue, and off-clamp surgery already avoids ischaemia. This trial says the surgical quality composite holds. What it cannot exclude is the thing surgeons actually worry about: p=0.08 for urinary fistula in a trial of 248 is not reassurance, it is an underpowered look at a rare complication that went the wrong way.

The other limit is the one the authors name first — a single surgeon at a single centre. A technique that depends on haemostatic judgement without a suture line to fall back on is precisely the kind that does not transfer intact from an expert to a learning curve.

• Read the fistula signal (p=0.08) as unresolved rather than negative before adopting the technique
• Confine any adoption to cT1-2N0M0 tumours of the complexity range studied
• Recognise this as single-surgeon evidence; the technique has no suture line as a fallback
• Keep 12-month renal function and imaging follow-up, since oncological follow-up here was one year
• Have a low threshold for temporary stenting if a urine leak is suspected — all nine were managed that way

The statistics, in plain English

Non-inferiority with a −10% margin means the trial asked whether sutureless surgery is no more than 10 percentage points worse, and the observed difference of −2.4% with a lower bound of −7.4% stays inside that. It does not show equivalence, and a 7 percentage point deficit would have been declared non-inferior. The fistula comparison is the real limitation: nine events across 248 patients gives almost no power, so p=0.08 should be read as a signal the trial could not resolve rather than as an absence of difference.

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