We read with great interest the study by Martel et al. comparing measured and estimated volumetry to determine the future liver remnant (FLR).1 The authors defined the measured volumes as the reference volumes, which may be inaccurate. The estimated method was not designed to correspond with measured volumetry, but to determine the metabolic requirement based on the patient's body-surface area.2 Using hepatic insufficiency as endpoint, Ribero et al. concluded that the measured method more frequently underestimated volumes; therefore the estimated method was a safer approach.3 The fact that Martel et al. concluded otherwise could indicate that the measured volumes to a greater extent are observer dependent and therefore not optimal for comparison between centers.
Using a yield difference of ≥5% between measured and estimated FLR; Martel et al. found discrepancy in 31.9% of the patients and concluded this could affect decision-making. However, according to Figure 2 in the Martel et al. paper, the measured volumes overestimated the FLR in the majority of patients with FLR <30%; which is far more dangerous than overestimation of estimated FLR in patients with FLR >40%. In another study, the estimated method accurately predicted postoperative hepatic insufficiency or death due to liver failure in all subsets of FLR (<20%, 20–29% and ≥30).4
Safety should remain the main endpoint when determining the appropriateness of volumetric methods in patients undergoing extensive liver resections. In our practice, we still consider the estimated method the safest because the measured method overestimates in the majority of patients with small FLR.
Conflict of interest
None declared.
References
- 1.Martel G., Cieslak K.P., Huang R., van Lienden K.P., Wiggers J.K., Belblidia A. Comparison of techniques for volumetric analysis of the future liver remnant: implications for major hepatic resections. HPB. 2015;17(12):1051–1057. doi: 10.1111/hpb.12480. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Vauthey J.N., Chaoui A., Do K.A., Bilimoria M.M., Fenstermacher M.J., Charnsangavej C. Standardized measurement of the future liver remnant prior to extended liver resection: methodology and clinical associations. Surgery. 2000;127(5):512–519. doi: 10.1067/msy.2000.105294. [DOI] [PubMed] [Google Scholar]
- 3.Ribero D., Amisano M., Bertuzzo F., Langella S., Lo Tesoriere R., Ferrero A. Measured versus estimated total liver volume to preoperatively assess the adequacy of the future liver remnant: which method should we use? Ann Surg. 2013;258(5):801–806. doi: 10.1097/SLA.0000000000000213. discussion 806–7. [DOI] [PubMed] [Google Scholar]
- 4.ishi Y., Abdalla E.K., Chun Y.S., Zorzi D., Madoff D.C., Wallace M.J. Three hundred and one consecutive extended right hepatectomies: evaluation of outcome based on systematic liver volumetry. Ann Surg. 2009;250(4):540–548. doi: 10.1097/SLA.0b013e3181b674df. [DOI] [PubMed] [Google Scholar]