Reconstruction of a traumatically transected Stensen's duct using facial vein graft.

Traumatic injuries to the lower third of the face can result in damage to various vital structures. We report a case of traumatically avulsed Stenson's duct and facial vein wherein the vein was used as a free graft to lengthen the duct. The paper highlights the need on how best to utilise the locally available and viable tissues as free grafts.

INTRODUCTION

Lacerations and deep penetrating injuries in the region of parotid gland can be accompanied by injury to important underlying structures in the area. They include buccal branches of the facial nerve, Stensen's duct which runs parallel to the nerve, transverse facial artery and vein. Especially in case of multiple injury settings injury to the parotid duct is often missed.[1]

Both surgical and nonsurgical methods have been advocated by various authors in the management of such injuries.[2]

Nonsurgical treatment aims to induce parotid gland atrophy by the use of antisialogogues, elastic bandages and refrain from oral intake until the injury has healed.[3]

Surgical techniques employed would depend on the extent and location of ductal damage. Complete transection of the main duct necessitates primary surgical exploration and microsurgical ductal reconstruction. Ductal reconstruction using vein grafts – autologous saphenous vein, antibrachial vein have been reported in the literature.[456] However, to the best of our knowledge, use of facial vein for the repair of transected Stensen's duct has not been described before. We report of a case of traumatic transection of the Stensen's duct repaired using a section of the facial vein which was also found ruptured in the surgical field.

CASE REPORT

A 40-year-old male patient reported with pain and swelling on the right side of the face. He complained of a discharge oozing from a sutured laceration in the right cheek region. There was a history of trauma to the right side of the face 6 days back from a machine used in farming. The resulting wound was sutured at a primary health center. The wound measuring about 5 cm extended from the corner of the mouth to roughly 2 cm anterior to the pinna of the right ear. Following clinical and biochemical examination of the discharge a diagnosis of right parotid duct transection and concomitant salivary ooze was reached. Facial nerve function was found to be intact. Under general anesthesia, surgical exploration of the wound revealed a transected parotid duct over the masseter muscle. The patency of the proximal portion of the duct was maintained by cannulation. The distal part of the duct could not be traced even after attempts were made by injecting normal saline through the papilla. Transected facial vein was found alongside the duct. It was decided to dissect the facial vein and use it as a free vein graft for lengthening the proximal segment of the duct [Figures 1 and 2]. Venous graft was anastomosed with the parotid duct with 10-0 nylon using a surgical microscope [Figures 3 and 4]. An 18-gauge intracath was used as a stent to support the graft [Figures 5 and 6]. This was pulled intraorally and transfixed with 3-0 silk [Figures 7 and 8]. A suction drain was placed and the wound was closed in layers [Figure 9]. The catheter was removed after 3 weeks. Sialography could not be performed in this case, as the patient did not give consent for it. The patient was followed up for a period of 1-year and no postoperative complications were noticed.

Figure 1

Transected facial vein dissected to be used as a free vein graft

Figure 2

Transected facial vein over the stent

Figure 3

Stensen's duct lengthened using facial vein graft

Figure 4

Vein graft sutured to the proximal stump of Stensen's duct

Figure 5

Wound closure in layers

Figure 6

Reconstructed Stensen's duct

Figure 7

Intraoral fixation of the graft over a stent

Figure 8

Closure

Figure 9

Two weeks post-operative

DISCUSSION

Deep penetrating injuries involving the parotid gland and duct have rarely been reported in the literature. Most of these injuries either go undetected or are reported only after complications set in. The Stensen's duct arises from the anterior aspect of the gland lying superficial to the masseter muscle. Here it is closely related to the transverse facial artery and buccal branch of the facial nerve. It then turns medially and penetrates the buccinator muscle to end at the papilla at the level of the second maxillary molar tooth. Extraorally the course of the duct can be imagined to follow a line extending from the tragus of the ear to the midpoint of the upper lip. Based on this anatomy von sickles classified these injuries into three: (A) Ductal injuries occurring within the glandular area. (B) Injuries of the duct over the masseter muscle. (C) Injuries anterior to the masseter muscle. This classification has been widely used in determining the management protocol of these injuries.[5]

Surgical and nonsurgical methods have been employed in the management of ductal injuries and its complications. Most injuries in the A region are treated by parotid capsule suture and external compression, C region injuries by reimplanting the Stensen's duct more posteriorly in the oral cavity. Treatment for B region injuries involves microsurgical repair with or without grafts. Various authors have described the use of several grafts and primary anastomosis with or without the use of stents.

Lewkowicz et al.[2] reviewed the accepted protocol of treatment for parotid duct injuries. They gave a treatment algorithm for sequencing the treatment and discussed the complications of PGDS injuries such as sialocele and parotid fistula.

Sujeeth and Dindawar[7] used an epidural catheter for parotid duct repair in which direct anastomosis of the severed duct was carried out by microsurgery and the catheter was removed after 10 days. They concluded that an epidural catheter was a novel technique of diagnosing and repairing a parotid duct transection. Ananthakrishnan[4] described a case where complete replacement of the transected duct was done with a 5 cm length of the autologous saphenous vein. No complication was noted and complete ductal function was maintained at follow-up. Chi Liang et al.[6] reported of 2 cases of reconstruction of a traumatically avulsed Stensen's duct defect using a vein graft harvested from the forearm as a conduit and discussed the advantages of delayed removal of the stent. Raveenthiran et al.[1] reported of a case of reconstruction of a traumatically avulsed parotid duct using a buccal mucosal flap in a 4-year-old boy. Kitamura and Togawa[8] described the use of Wharton's duct as a graft to reanastomose the Stensen's duct. This surgical protocol is, however, controversial as it may result in loss of function of the submandibular gland.

Chudakov and Ludchik[9] studied the microsurgical repair of Stensen's and Wharton's duct on dogs by different ways using free autologous vein grafts or by wrapping masseter fascia around the venous grafts. They noted histological changes in the autogenous vein grafts from the 5th postoperative day-necrosis, intima exfoliation, and edema of the media and adventitia. By the 21st postoperative day, complete epithelization of the intimal layer occurred. In the case where masseter muscle fascia was wrapped around the graft, fewer adhesions and scarring was observed and by the 14th postoperative day complete intimal epithelization was seen.

Dumpis and Feldmane[10] studied the results achieved by experimental microsurgical suturing of salivary ducts in dogs. After venous graft transplantation, they observed that the transplant was not observed histologically 2 months after anastomosis. They also assessed the possibility of long-term stenting aiding in postoperative recovery. They concluded that a period of 7 days stenting seemed too short for adequate recovery.

Our case was different as we encountered a transected facial vein along with the avulsed duct. As the injury was 6 days old sufficient venous collateral circulation was probably already established and no bleeding was encountered so we decided to use facial vein as a free vein graft. Our technique was successful and no complications were encountered till 1-year of follow-up.

CONCLUSION

A case of parotid duct transection managed surgically by anastomosing with an autogenous vein graft harvested from the transverse facial vein over a stent has been described. We conclude that in patients who present late with facial vein transection along with an avulsed Stensen's duct using the facial vein as a free graft can be a simple and safe alternative.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflict of interest.