Duplication of the internal jugular vein: a rare presentation during neck dissection.

Case report Duplication of the internal jugular vein: a rare presentation during neck dissection Samriddhi Burman,1 Sameer Pandey ‍ ‍,1,2 Sruthi Rao ‍ ‍,3 Santhosh Rao ‍ ‍1 1 Dentistry - Oral & Maxillofacial Surgery, All India Institute of Medical Sciences, Raipur, Tatibandh, India 2 Craniomaxillofacial Surgery, All India Institute of Medical Sciences, Rishikesh, Uttarakhand, India 3 Oral & Maxillofacial Surgery, Rungta College of Dental Sciences and Research, Bhilai, Chhattisgarh, India Correspondence to Dr Santhosh Rao; Accepted 1 February 2021 SUMMARY The anatomical variations of the internal jugular vein (IJV) is a well-documented phenomenon which may depend on the course of drainage, fenestration in the vein, bifid formation, variations in the tributaries and so on. However, a true duplication of the IJV is a rare entity on its own and is seldom reported in the literature. We report a case of true duplication of IJV which is an incidental discovery during the course of neck dissection. BACKGROUND The internal jugular vein (IJV) drains the major portions of the head and neck. IJV descends within the carotid sheath and unites with the subclavian vein to form the brachiocephalic vein. The IJV is an important anatomical reference for the radiologists, head and neck surgeons, intensivists and it is frequently used for central venous access. Identification of the IJV is essential to every neck dissection.1 Complex embryologic development of vascular system often results in clinically relevant anomalies.2 The anatomical variations of the IJV is a well-documented phenomenon which may depend on the course of drainage, fenestration in the vein, bifid formation, variations in the tributaries and so on. However, a true duplication of the IJV is a rare entity on its own and is seldom reported in the literature. We report a case of true duplication of IJV © BMJ Publishing Group Limited 2021. No commercial re-use. See rights and permissions. Published by BMJ. To cite: Burman S, Pandey S, Rao S, et al. BMJ Case Rep 2021;14:e239007. doi:10.1136/bcr-2020239007 Figure 2 Picture depicting the joining of two IJVs below the level of omohyoid muscle. IJVs, internal jugular veins. which is an incidental discovery during the course of neck dissection. CASE PRESENTATION A 40- year- old male reported to our department with ulceroproliferative lesion of the right gingivobuccal sulcus. Diagnosis of oral squamous cell carcinoma was made with clinically positive ipsilateral neck node. After thorough workup the case was planned for surgical wide excision with comprehensive modified radical neck dissection (MRND) with suitable reconstruction of the defect. MRND was started using a standard Macfee incision. During the course of the neck dissection after the sternocleidomastoid muscle was divided inferiorly and retracted anteriorly to expose level IV and III lymph nodes, an enlarged lymph node was found in close relation to IJV. While the IJV was retracted carefully to access the lymph node, a second vein medial and posterior to the IJV was identified with same calibre and joining IJV below level of omohyoid muscle (figures 1 and 2) This intraoperative finding was further complicated by multiple posterior tributaries of both the veins hence demanded a more cautious approach from the surgical team. However, the MRND was completed with saving both the IJVs and the surgery proceeded as per the initial plan. A careful examination of contrast-enhanced CT scan axial section revealed duplication of IJV at level of C6 (figure 3) DISCUSSION Figure 1 Clinical picture showing two IJVs marked as I and II which are joining to form a single large vein marked III below the level of omohyoid. IJVs, internal jugular veins. It is common knowledge that right IJV is slightly larger in calibre when compared with left side. Hence a larger calibre on right side increases the risk of intraoperative blood loss. Furthermore any anatomical variation can make the surgery more complicated. Mumtaz and Singh have reported Burman S, et al. BMJ Case Rep 2021;14:e239007. doi:10.1136/bcr-2020-239007 1 Case report scans would have led us to be more vigilant during our surgical procedure. Learning points ►► The authors are of the opinion that there is a need of increased awareness among the head and neck surgeons about the possible variations in head and neck vasculature. ►► A careful study of preoperative CT scan is advised which affects the intraoperative surprises during a neck dissection. Figure 3 Duplication of IJV at the level of C6 on contrast-enhanced CT scan, axial section. IJV, internal jugular vein. that more than two- third of variations of IJV occur on left side.3 Often reported interchangeably in literature the terms appear confusing and lack a delineation. Mumtaz has suggested omohyoid muscle as reference point so that any division of IJV below or at its level is called duplication and above it is called bifurcation. In our case, the division was below the level of omohyoid and hence it can be safely termed as duplication of IJV. Moreno-Sánchez reported a case of fenestration of IJV and suggested that variations of IJV increase the chances of intraoperative blood loss and make clearance of lymph nodes difficult as was in our case.1 In our case, there was a clear bifurcation of IJV visible on right side carotid sheath region. The authors hence suggest a careful preoperative study of CT to rule out any variations in the vasculature of head and neck. Duplication of a major vessel such as IJV is significant with only four such cases reported till date.3 The surgical implications cannot be over emphasised and a careful study of the CT Contributors SaR and SP were the operating surgeons, SP and SB were involved in postoperative care of the patient. The literature search was conducted by SrR and SP. Manuscript was prepared by SP and SrR. Final proofreading was done by SB and SaR. All authors accepted the final proof. Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors. Competing interests None declared. Patient consent for publication Obtained. Provenance and peer review Not commissioned; externally peer reviewed. ORCID iDs Sameer Pandey http://orcid.org/0000-0002-7070-8237 Sruthi Rao http://orcid.org/0000-0002-7781-9319 Santhosh Rao http://orcid.org/0000-0003-0274-7442 REFERENCES 1 Moreno-Sánchez M, Hernández Vila C, González-García R, et al. Fenestrated internal jugular vein: a rare finding in neck dissection. Int J Oral Maxillofac Surg 2015;44:1086–7. 2 Rao S, Pandey S, Kumar Y, et al. Bifurcation of external jugular vein: an anatomical variation during neck dissection. Oral Maxillofac Surg 2018;22:475–6. 3 Mumtaz S, Singh M. Surgical review of the anatomical variations of the internal jugular vein: an update for head and neck surgeons. Ann R Coll Surg Engl 2019;101:2–6. Copyright 2021 BMJ Publishing Group (...truncated)