Intermittent inflow occlusion during robotic donor hepatectomy: technical refinement in a high-stakes operation through a randomized controlled trial

Living donor hepatectomy remains one of the most ethically and technically demanding procedures in hepatobiliary surgery and liver transplantation. Few other areas of surgery judge innovation against such a narrow margin for acceptable operative risk. The donor is a healthy volunteer undergoing a major liver operation; therefore, any incremental clinical benefit must be carefully weighed against even small possibilities of harm. This is precisely why minimally invasive donor hepatectomy has advanced very cautiously among high-volume centers, despite encouraging data. These considerations help explain why robotic donor hepatectomy (RDH) remains concentrated only in a limited number of highly experienced liver transplantation programs (1,2).

In this context, the randomized trial by Kunju and colleagues is particularly relevant (3). The authors randomized 113 donor-recipient pairs to robotic right donor hepatectomy with or without intermittent inflow occlusion (IIO), with 56 assigned to the IIO arm and 57 to the control arm. They reported significantly lower blood loss during parenchymal transection and lower total blood loss in the IIO arm. Furthermore, the reduction in blood loss was not associated with longer warm or cold ischemia times, worse postoperative donor hepatic function, higher donor morbidity, or worse early recipient outcomes. Recipient peak alanine aminotransferase and international normalized ratio were also significantly lower in the IIO group, while other clinically relevant endpoints remained comparable.

At first glance, some readers may question whether the magnitude of benefit is large enough to matter clinically. The overall median difference in total blood loss was modest (55 mL), and the trial does not establish a clear reduction in major donor complications, transfusion requirements, or recipient mortality. Yet, focusing only on the magnitude of effect may risk overlooking the study’s most important contribution. In liver donor surgery, even a relatively small gain in hemostatic control deserves attention, particularly when it occurs during the most delicate phase of parenchymal transection. When IIO was used, visualization was improved because of reduced bleeding when transecting liver parenchyma near the middle hepatic vein and working around the hepatic duct at the level of hilar plate. These are two critical areas in donor hepatectomy procedure that deserve maximum visual clarity and technical precision. The main message of this trial was that IIO appears feasible, safe, and technically useful in undertaking right donor hepatectomy within mature hepatobiliary and liver transplantation programs with minimally invasive surgery capabilities.

This study brought critical findings because IIO has historically occupied an uneasy and controversial position in living donor surgery. In conventional open liver resection, portal triad clamping is a familiar tool used to reduce blood loss, widely applied for liver tumor resection. In donor hepatectomy, however, concerns about ischemia-reperfusion injury to both the remnant liver and the graft have limited its routine use. Earlier open-donor studies suggested that IIO could reduce blood loss without compromising donor or recipient safety, and randomized evidence in open right lobe donation already challenged the assumption that this maneuver was inherently harmful (4-6). Kunju et al. extend the discussion into the robotic setting, where a cleaner operative field from improved hemostasis may be especially valuable.

The study also has broader conceptual value for the evolution of RDH. Currently, the field no longer needs feasibility reports alone. It now requires a careful evaluation of which technical adjuncts can make an already feasible operation more reproducible and more forgiving without compromising the donor safety standards. In this sense, the present trial represents an important maturation step. It tests not whether RDH can be done, but how it can be optimized. That question aligns closely with prior consensus recommendations, which emphasize structured implementation, institutional expertise, and an unwavering priority on donor welfare (1). Importantly, the study was not confined to overly simplified graft selection, as donors with biliovascular anatomical variations were also included in the study. This point is relevant, because it suggests that the observed benefit was not merely achieved in idealized technical scenarios, but within a case mix that more closely reflects the real-life anatomical complexity encountered in mature donor hepatectomy programs.

By the same token, a critical assessment is important. This was a single-center study performed by a highly experienced team in a country where living donor liver transplantation predominates overall liver transplantation, and its findings should not be extrapolated indiscriminately to early-adopter programs in the East and more important in the West, where cadaveric liver transplantation is essentially the rule. The technical workflow is also center-specific: the transection strategy, routine subtotal middle hepatic vein harvest, and the authors’ operative sequencing may all interact with the apparent utility of IIO. Moreover, the recipient biochemical signals, while intriguing, should still be regarded as hypothesis-generating rather than definitive evidence of graft protection. Even within a well randomized study, residual bias and imbalances can persist, and the study was not primarily powered to demonstrate recipient benefit, as also acknowledged by the authors. It is also notable that the only conversions to open surgery occurred in the IIO arm, which reminds us that “safe in this series” should not be confused with universally risk-free practice. For these reasons, the most balanced interpretation is not that IIO should become routine in RDH, but that it should no longer be treated as a conceptual taboo, especially in situation of hepatic bleeding. The trial supports the view that, within experienced programs, IIO may be a reasonable selective adjunct when hemostatic control is necessary during RDH. This trial ultimately suggests that IIO may be used as a selective technical adjunct during the most bleeding-prone and precision-dependent steps of robotic donor transection without hesitation.

Finally, progress in living donor surgery rarely comes from dramatic innovation alone. More often, it comes from careful refinement of many techniques, validated step by step against the uncompromising standard of donor safety. By showing that an old maneuver can be revisited thoughtfully in a new operative platform, Kunju and colleagues may not have defined a new universal standard, but they meaningfully reframed the conversation—and that is a valuable contribution in one of the highest-stakes operations in modern minimally invasive liver surgery.

Acknowledgments

None.

Footnote

Provenance and Peer Review: This article was commissioned by the editorial office, Translational Gastroenterology and Hepatology. The article has undergone external peer review.

Peer Review File: Available at https://tgh.amegroups.com/article/view/10.21037/tgh-2026-0056/prf

Funding: None.

Conflicts of Interest: Both authors have completed the ICMJE uniform disclosure form (available at https://tgh.amegroups.com/article/view/10.21037/tgh-2026-0056/coif). The authors have no conflicts of interest to declare.

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