Letter to the editor regarding ‘Using computed tomography to evaluate anatomic landmarks in Taiwanese trauma patients for insertion of resuscitative endovascular balloon occlusion of the aorta: a retrospective cohort study’ – liberating REBOA from imaging

International Journal of Surgery, vol. 110, pp. 8202–8204

Abstract

Anatomic Landmarks in Taiwanese Trauma Patients for Insertion of Resuscitative Endovascular Balloon Occlusion of the Aorta: A Retrospective Cohort Study' with great interest.We congratulate the authors with the anatomical and morphological insights gained through this well-designed and accurately conducted study which included the often-overlooked skin to femoral artery depth and total balloon length [1] .In addition, we would like to share some considerations and recommendations for future research.The authors have focused on an important, but often forgotten subject; the possible influence of racial anatomical differences on successful performance of (endo-) vascular interventions, such as endovascular aneurysm repair (EVAR) and stenting.Determining optimal introduction depths for REBOA without radiographic confirmation is no different.Although a one-size-fits-all strategy may be the most practical, a sizeable part of the world population would receive incorrect balloon positioning when using a solitary fixed-distance catheter insertion length.This could result in inadequate hemorrhage control or iatrogenic limb and (multi) organ ischemia-reperfusion injury.Focus on Asian populations is, therefore, of great importance.We have recently conducted a similar study in a Caucasian population, including 1354 individuals aged 18-90 years, to evaluate aortic and iliofemoral arterial morphology, determine (combined) sex and age-based variable-distance insertion lengths, and validate previously proposed introduction depths [2] .Starting at the same femoral arterial access points, comparable lengths were seen with significantly longer distances in males, the elderly, and on the right side.The universal zone I insertion length, excluding skin depth, was 430 mm.Optimal zone III insertion lengths ranged between 234 and 264 mm, compared to 255 mm in the Taiwanese study.As zone III length was very consistent, length variability and elongation below the diaphragm predominantly originated in the iliofemoral trajectory and zone II.Intravascular distances increase with torso length.Considering varying body heights between nations and races, it is conceivable that intravascular distances also differ between races.Legislative restrictions often do not allow racial comparison and research specifically focused on these differences is scarce.We invite the authors and others for an international collaboration to compare datasets and answer the question of whether existing REBOA insertion lengths are universally applicable or should indeed be adjusted per region.In contrast to what the authors mention, multiple Asian studies focused on aorto-iliofemoral morphology have been conducted; various Japanese studies, two other Chinese than those cited and one Korean study, including over 4000 individuals [3][4][5] .These Asian studies show similar central aortic but shorter iliofemoral distances compared to our study.With this latest combination of morphological observations, the quest for the optimal fluoroscopy-free zone I balloon placement method can be concluded.The authors have confirmed that a fixed-distance insertion length 47.5 cm (range 44-48 cm) or the use of the mid-sternum as anatomical external landmark are dependable and universally applicable methods for fluoroscopy-free zone I REBOA as previously shown by Borger et al. [6] .However, in earlier studies using the umbilicus as reference point for zone III caused erroneous iliac artery balloon placement in 67-98%.This is in stark contrast with Chien et al. showing 95% accuracy rates when using umbilicus-based equations.Although multiple strategies have been proposed to enable

Authors 3

1. Jan C. van de Voort corresponding Aachen Department of Surgery, Alrijne Hospital

   Erasmus MC · Alrijne Ziekenhuis

   Affiliation as printed

   Department of Surgery, Alrijne Hospital, Leiderdorp, The Netherlands

   Department of Surgery, Trauma Research Unit, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands

   Trauma Research Unit, Department of Surgery, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands

2. Boudewijn L.S. Borger van der Burg Aachen Department of Surgery, Alrijne Hospital

   Alrijne Ziekenhuis · Ministry of Defence

   Affiliation as printed

   Department of Surgery, Alrijne Hospital, Leiderdorp, The Netherlands

   Defense Healthcare Organization, Ministry of Defense, Utrecht, The Netherlands

3. Rigo Hoencamp Aachen Department of Surgery, Alrijne Hospital

   Erasmus MC · Alrijne Ziekenhuis · Ministry of Defence

   Affiliation as printed

   Defense Healthcare Organization, Ministry of Defense, Utrecht, The Netherlands

   Department of Surgery, Alrijne Hospital, Leiderdorp, The Netherlands

   Department of Surgery, Trauma Research Unit, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands

   Trauma Research Unit, Department of Surgery, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands