Beyond estimates: optimizing surgical strategies through accurate blood loss measurement

We read with great interest the article titled “The Goal of Intraoperative Blood Loss in Major Hepatobiliary Resection for Perihilar Cholangiocarcinoma” by Kawakatsu and colleagues (1), published in the Annals of Surgery. The authors deserve recognition for conducting a clear and ambitious study aimed at evaluating the impact of intraoperative blood loss (IBL) on postoperative complications in one of the most challenging scenarios in hepatobiliary surgery.

As highlighted by a recent systematic review (2) and a Delphi consensus from the European-African Hepato-Pancreato-Biliary Association (E-AHPBA) (3), IBL is widely recognized as a clinically significant predictor of postoperative outcomes. However, the estimation of IBL is often inconsistent and heterogeneous, undermining the reliability of derived correlations. In contrast, Kawakatsu et al. (1) adopted a rigorous and systematic approach to quantifying blood loss by meticulously subtracting saline volumes and the dry weight of surgical gauze from the combined volume of suction reservoirs and the weight of blood-soaked gauze. Furthermore, their use of adjusted blood loss (aBL), normalized for body weight, provides a more standardized metric for assessing its impact.

The study identifies a nonlinear association between aBL and the Comprehensive Complication Index (CCI), emphasizing two critical aBL cutoff values (<10 and <20 mL/kg). While these findings are noteworthy, several aspects warrant further consideration.

The authors report a large series of patients undergoing complex surgical procedures (43% Bismuth IV cases, involving hemihepatectomies or extended hemihepatectomies), with arterial (19.8%) and portal (30.4%) resections, and likely complex biliary reconstructions. The reported median blood loss [964 mL, interquartile range (IQR), 673–1,417 mL] is relatively low, even when compared to benchmark outcomes (4) (<1,100 mL), reflecting the group’s efforts to minimize bleeding. On the contrary, the reported CCI values (40.6) appear rather high compared to the same benchmark values (<30.5). Additionally, although statistically significant, the difference in terms of CCI between the two groups (aBL ≤10 and >10 mL/kg) seems to have limited clinical relevance. A blood loss goal of <10 mL/kg appears hardly achievable in several settings, as acknowledged by the authors. This raises questions about the practical significance of the findings.

Another notable limitation of the study is the lack of detailed reporting on the specific types of complications that most significantly contribute to CCI increases. Complications such as bile leakage, liver failure, or sepsis may have distinct etiologies and prognostic implications. The absence of granular analyses limits the ability to establish precise correlations between IBL and postoperative outcomes and to speculate on the underlying physiopathology.

As correctly pointed out by Ratti et al. (5), bleeding may not directly cause complications but rather represent an epiphenomenon of intraoperative complexity. Factors such as challenging anatomy, advanced oncological burden, or the need for vascular resections likely contribute to both increased IBL and a heightened risk of complications.

To determine whether IBL directly influences postoperative outcomes or merely reflects surgical complexity, robust methodological evidence is essential. To achieve this, precise and quantifiable measures, like those presented in this paper, are highly valuable.

Moreover, even if a direct causal relationship cannot be established, this does not diminish the importance of minimizing IBL. While excessive blood loss may indicate a complex surgical scenario, a bloodless and precise procedure could reflect a more meticulous surgical approach, which, we can speculate, may be associated with fewer complications. This issue is particularly significant because, among the many factors influencing postoperative outcomes, IBL remains one of the few that can be actively modified. This may also be extremely relevant when considering patients with specific religious beliefs that prohibit transfusions.

To this respect, a comprehensive goal-oriented anesthesiology approach is of paramount importance. Preoperative anemia correction, judicious fluid administration and thorough central venous pressure management can have a significant impact on intraoperative bleeding (6,7). This reflects both on the need for blood transfusions and on the occurrence of complications related to poor visualization in a bloody surgical field.

Attention to surgical technique is equally important. Meticulous hemostasis, prevention of multifocal oozing, and precise parenchymal dissection using advanced energy devices and cavitron ultrasonic surgical aspirators are essential strategies to minimize unnecessary blood loss (8). Selective pedicle ligation and precise identification of transection planes, coupled with thorough preoperative vascular reconstruction and modelling, may also enhance precision and avoid bleeding (9).

Minimally invasive approaches have recently demonstrated potential in reducing IBL compared to open procedures (10,11). Both minor and complex major laparoscopic liver resections performed at high-volume hepatobiliary centers have shown favorable short- and long-term outcomes, provided that oncologic principles are respected and a steep learning curve is achieved by a dedicated team.

Robotic surgery has been proposed as an ideal approach for perihilar cholangiocarcinoma (pCCA), offering significant technical advantages, particularly for hepatic hilum dissection and bilio-enteric or vascular reconstructions (12). The robotic platform provides distinct benefits, including enhanced dexterity, superior precision, and the ability to replicate human hand movements with greater accuracy. However, despite its potential, the evidence supporting robotic surgery for pCCA remains limited. To date, only a few pioneering series from expert centers have been published (13,14), with preliminary data suggesting safety and feasibility of robotic resections in this complex patient population.

In conclusion, the study by Kawakatsu et al. (1) provides valuable insights into the role of IBL in major hepatobiliary surgery. Their methodological rigor is commendable and adds significant value to their findings. While the clinical relevance of their results remains to be fully established, their focus on this important issue is highly commendable, as is the emphasis on strategies to minimizing blood loss.

Acknowledgments

None.

Footnote

Provenance and Peer Review: This article was commissioned by the editorial office, HepatoBiliary Surgery and Nutrition. The article did not undergo external peer review.

Funding: None.

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://hbsn.amegroups.com/article/view/10.21037/hbsn-2025-75/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

References

1. Kawakatsu S, Mizuno T, Yamaguchi J, et al. The Goal of Intraoperative Blood Loss in Major Hepatobiliary Resection for Perihilar Cholangiocarcinoma: Saving Patients From a Heavy Complication Burden. Ann Surg 2023;278:e1035-40. [Crossref] [PubMed]
2. Perri G, Marchegiani G, Reich F, et al. Intraoperative Blood Loss Estimation in Hepato-pancreato-biliary Surgery- Relevant, Not Reported, Not Standardized: Results From a Systematic Review and a Worldwide Snapshot Survey. Ann Surg 2023;277:e849-55. [Crossref] [PubMed]
3. Perri G, Sparrelid E, Siriwardena AK, et al. Estimation of intraoperative blood loss in hepatopancreatobiliary surgery: a Delphi consensus process of the European-African Hepato-Pancreato-Biliary Association (E-AHPBA). Br J Surg 2024;111:znae256. [Crossref] [PubMed]
4. Mueller M, Breuer E, Mizuno T, et al. Perihilar Cholangiocarcinoma - Novel Benchmark Values for Surgical and Oncological Outcomes From 24 Expert Centers. Ann Surg 2021;274:780-8. [Crossref] [PubMed]
5. Ratti F, Marino R, Aldrighetti L. Comment on "The Goal of Intraoperative Blood Loss in Major Hepatectomy Resection for Perihilar Cholangiocarcinoma Saving Patients From a Heavy Complication Burden". Ann Surg Open 2024;5:e371. [Crossref] [PubMed]
6. Liu TS, Shen QH, Zhou XY, et al. Application of controlled low central venous pressure during hepatectomy: A systematic review and meta-analysis. J Clin Anesth 2021;75:110467. [Crossref] [PubMed]
7. Jongerius IM, Mungroop TH, Uz Z, et al. Goal-directed fluid therapy vs. low central venous pressure during major open liver resections (GALILEO): a surgeon- and patient-blinded randomized controlled trial. HPB (Oxford) 2021;23:1578-85. [Crossref] [PubMed]
8. Yu ZN, Xu LL, Li L, et al. Comparison of the outcomes between ultrasonic devices and clamping in hepatectomy: a meta-analysis. World J Surg Oncol 2024;22:304. [Crossref] [PubMed]
9. Cui DP, Fan S, Guo YX, et al. Accurate resection of hilar cholangiocarcinoma using eOrganmap 3D reconstruction and full quantization technique. World J Gastrointest Surg 2023;15:1693-702. [Crossref] [PubMed]
10. Berardi G, Lucarini A, Colasanti M, et al. Minimally Invasive Surgery for Perihilar Cholangiocarcinoma: A Systematic Review of the Short- and Long-Term Results. Cancers (Basel) 2023;15:3048. [Crossref] [PubMed]
11. Wang W, Fei Y, Liu J, et al. Laparoscopic surgery and robotic surgery for hilar cholangiocarcinoma: an updated systematic review. ANZ J Surg 2021;91:42-8. [Crossref] [PubMed]
12. Hobeika C, Pfister M, Geller D, et al. Recommendations on Robotic Hepato-Pancreato-Biliary Surgery. The Paris Jury-Based Consensus Conference. Ann Surg 2025;281:136-53. [Crossref] [PubMed]
13. Cillo U, D'Amico FE, Furlanetto A, et al. Robotic hepatectomy and biliary reconstruction for perihilar cholangiocarcinoma: a pioneer western case series. Updates Surg 2021;73:999-1006. [Crossref] [PubMed]
14. Sucandy I, Marques HP, Lippert T, et al. Clinical Outcomes of Robotic Resection for Perihilar Cholangiocarcinoma: A First, Multicenter, Trans-Atlantic, Expert-Center, Collaborative Study. Ann Surg Oncol 2024;31:81-9. [Crossref] [PubMed]