Prevention of injury to right hepatic artery during laparoscopic cholecystectomy

Introduction

Laparoscopic cholecystectomy (LC) is a common surgical procedure taking place both in the elective and the emergency settings. Without careful dissection and anticipation of potential biliary and vascular variations, major intraoperative complications may occur such as bile duct injuries, severe bleeding or hepatic ischemia (1,2). The reported incidence of common bile duct (CBD) injuries following LC is estimated to be between 0.3 to 0.7%, three times higher than that following open surgery (2). With reference to vascular anomalies, these are mostly related to the cystic artery (CA) and right hepatic artery (RHA) anatomy and the incidence rate of conversion to open surgery due to intra-operative vascular lesions is approximately 0–1.9% (1,3,4).

The Critical View of Safety (CVS) method of identification of CA and cystic duct (CD) during LC was initiated with aim to minimize surgical risks via a standardized approach universally (5). However, the delineation of CA can be occasionally technically difficult due to third structures within the hepato-cystic triangle (arteries in 36.2%) (1,4,6). One anatomical variation that has been described is the caterpillar hump or Moynihan’s hump, a sinuous tortuosity of the RHA, which occupies the major portion of Calot’s triangle (7-10). Its incidence has been noted in up to 12.9% cases (7,9). Herein, we describe two original cases of challenging dissection of Calot’s triangle, resulting in the identification of unusual anatomy of RHA.

Technical considerations

In both cases, an unknown structure was adjacent and attached closely to the CA, not allowing a clear view of the hepatocystic triangle (Figure 1A). The direct dissection of the unknown structure aiming immediately towards CVS was avoided due to high suspicion of anatomical variations of RHA. Careful dissection peripherally to the unknown structure, through the Calot triangle, upwards and towards the direction of the gallbladder (GB) led to retraction of the unknown structure and its separation from the surrounding tissues (Figure 1B & Figure 2). Consequently, the unknown structure was identified as the caterpillar hump of RHA and the desirable CVS was achieved.

Figure 1 Overview of the anatomy during laparoscopic cholecystectomy before and after the use of traction. (A) Before the use of traction, the triangle represents the cystohepatic triangle, which is formed by the CD, the CHD, and inferior edge of the liver. The circle encompasses an unknown structure containing the RHA. The CA originates from the RHA. (B) With the application of traction, the arrow shows the plane of dissection, which is upwards and towards the direction of the gallbladder and not towards the unknown structure in the circle. CA, cystic artery; CD, cystic duct; CHD, common hepatic duct; RHA, right hepatic artery.

Figure 2 The perioperative images before (A,C) and after (B,D) the peripheral dissection of unknown structures during two laparoscopic cholecystectomies, resulting in the prompt recognition of the right hepatic artery. The black arrows demarcate the line of dissection. Two right-pointing blue arrows between the two groups’ images indicate the progression from “before” to “after” dissection. CA, cystic artery; CD, cystic duct; RHA, right hepatic artery.

Conclusions

The CVS is a fundamental aspect of safe surgical dissection in LC to avoid biliary injuries, however it is not the only aspect. Arterial variations of RHA may impede the CVS and should also be considered by the operating surgeon, particularly in cases of unknown structures closely to the CA.

Acknowledgments

The authors acknowledge Ms. Olga Souvermezoglou for her contribution towards the design of figures and her expertise in medical illustration.

Footnote

Provenance and Peer Review: This article was a standard submission to the journal. The article has undergone external peer review.

Peer Review File: Available at https://ales.amegroups.com/article/view/10.21037/ales-25-13/prf

Funding: None.

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://ales.amegroups.com/article/view/10.21037/ales-25-13/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. All clinical procedures described in this study were performed in accordance with the ethical standards of the institutional research committee and with the Helsinki Declaration and its subsequent amendments. Written informed consent was obtained from the patients for the publication of this “Images in Clinical Medicine” and accompanying images.

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/.

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