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Reliable and safe salivary duct repositioning technique with partial transection and intraductal stenting: Technical notes

Published:February 01, 2022DOI:https://doi.org/10.1016/j.anl.2022.01.003

      Abstract

      Salivary duct repositioning is often performed after excision of malignant tumors or removal of sialoliths to maintain salivary function and minimize the risk of swelling or pain due to the obstruction of the gland. However, there is risk of intraoperative tissue damage due to traumatic manipulation, leading to stenosis; in addition, the small diameter of the duct also renders this procedure difficult. Recently, we improved our method of salivary duct repositioning as follows. In the first technique, partial transection is made on the lateral wall of the duct ligated with thread at the end. Pulling the thread provides a view of the lumen, and appropriate tension enables a reliable and non-invasive procedure without requiring the operator to grasp the edge of the duct directly. When the diameter of the duct is small, intraductal stenting, the second technique, can be combined with the former technique by probe insertion to expand the lumen. Our approach is technically easy and simple which can be accepted by any clinicians and it could also be a promising technique that can serve as a less invasive and effective treatment.

      Keywords

      1. Introduction

      Salivary duct repositioning is often performed after excision of a malignant tumor or removal of sialoliths to maintain salivary function and to minimize the risk of swelling or glandular pain resulting from salivary duct obstruction [
      • Ord R.A.
      • Lee V.E.
      Submandibular duct repositioning after excision of floor of mouth cancer.
      ,
      • Sakakibara A.
      • Minamikawa T.
      • Hashikawa K.
      • Sakakibara S.
      • Hasegawa T.
      • Akashi M.
      • et al.
      Does salivary duct repositioning prevent complications after tumor resection or salivary gland surgery?.
      ]. As salivary duct repositioning is optionally performed with the forementioned procedures in almost all cases, the procedure must be simple, reliable, and effective within a short time. Permanent patency is also required after the operation.
      During salivary duct repositioning, there is risk of tissue damage due to traumatic manipulation; for example, the use of forceps to directly grasp the duct can cause stenosis. Further, the procedure is rendered difficult when the duct has a short diameter.
      So far, few reports have provided a detailed description of salivary duct repositioning procedures. Recently, we improved our method of salivary duct repositioning (Fig. 1). Partial transection was made on the lateral wall of the duct ligated with thread at the end. Pulling the thread provides a view of the lumen, and appropriate tension enables a reliable and non-invasive surgical procedure without requiring the operator to grasp the edge of the duct directly. For cases in which the duct has a small diameter, the described procedure is combined with intraductal stenting by probe insertion to expand the lumen. Here, we describe the application of this repositioning technique, involving partial transection and intraductal stenting, in two cases and show that these approaches allow a simple and reliable operation with excellent functional repair of the salivary duct.
      Fig 1
      Fig. 1Diagrammatic representation of partial transection and intraductal stenting. At the transection site, a small part of the wall of the duct remains uncut, where the first stitch (1) is placed. The second stich (2) is placed at 180° to the first stitch here.

      2. Surgical procedures

      We describe our method (Fig. 1) in the case of a 64-year-old female patient with a squamous cell carcinoma of the right tongue, who underwent the partial glossectomy (Fig. 2), full-thickness skin graft, and submandibular duct repositioning. All procedures can be performed with a naked eye or under 2-3 folds magnifying glasses.
      Fig 2
      Fig. 2A. The exposed duct in the wound was stripped after ligation. The repositioning site was marked with ink (arrow); B. The ligated duct was pulled away from repositioning site using ligated threads and the lateral wall of the duct was partially transected. Placement of stiches was easy because of traction of the duct and intraductal stenting; C. Distal part of the duct was cut off and all threads were knotted; D. The repositioned orifice was open 6 months postoperatively.
      The duct was excised concomitant to tumor resection. After confirming clear negative margins of cancer resection intraoperatively, the repositioning was performed. The duct was tied near the stump with a 4-0 silk thread, with which the duct could be pulled without needing to grasp the edge of the duct with forceps. The position of the knot relative to the duct should be kept in mind to prevent twisting of the duct during manipulation (Fig. 2A). Further, dissecting the duct from the surrounding tissue enabled us to manipulate it without tension. The repositioning site should be set in the normal mucosa with a distance of at least 1 cm from the resection area. An incision, with dimensions more than the diameter of the ducts, was made with a steel scalpel. A mosquito forceps with a slim head was inserted into the incision site to pull the thread tied to the duct from the resection site to the repositioning site paying attention not to twist the duct. Under the traction of the thread, with appropriate tension, a transverse incision was made on the lateral wall of the duct to a depth of approximately four-fifths to three quarters of the wall, and a probe inserted into the duct to extend the lumen (Fig. 2B). The distal part of the transection site was used for traction and would be finally cut off. When it is difficult to expand the lumen, the insertion of a probe with a blunt end for medical use, such as Bowman probe, into the lumen for stenting might facilitate subsequent procedures. The first stitch was placed at the uncut part of the duct between the distal part scheduled to be disconnected and the preserved part, from the inside of the duct to its outside, with a 7-0 monofilament thread (Fig. 1 red thread #1). Traction of the thread could expand the lumen, enabling precise placement of the stich, while being careful not to twist the duct. Then, that needle was passed into the mucosa of the floor of the mouth. This 7-0 thread remained untied until the second suture was placed, or after all the stitches between the whole circumference of the edge and the oral mucosa were complete. The second stitch was placed at 180° from the first suture (Fig. 1 red thread #2). The first two stitches might be knotted at this time or until all stitches are completed. Two stitches (at 90° and 270° to the first stitch) to four stitches (at 60°, 120°, 240°, and 300°) were added depending on the diameter of the duct and balance. In the present case, a total of 6 sutures were placed (Fig. 2C). Stenting was used only when needed. Salivary secretion from the relocated orifice was confirmed by pressing the submandibular gland. Then, all the sutures were knotted. Finally, the distal part, which remained uncut for traction, was cut off (Fig. 2C).
      Postoperatively, we confirmed the patency of the relocated duct, removed pseudomembranes made of extra fibrin over the orifice, and applied steroid ointment on a daily basis. The sutures were removed 14 days postoperatively. Six months postoperatively, optical examination showed that the relocated orifice was patent and salivary secretion was present (Fig. 2D).

      2.1 Case 1

      The case was presented in “surgical procedures” above (Fig. 2). Stenting was used only when needed. Eventually, a total of 6 stitches with Nylon 7-0 were made (Fig. 2C). The postoperative clinical course has been uneventful. All the threads were removed 14 days after the operation. The optical finding at 6 months after the operation showed the relocated orifice was open and salivary secretion was present (Fig. 2D).

      2.2 Case 2

      A 77-year-old female presented with squamous cell carcinoma of the right tongue. Submandibular duct repositioning was performed in combination with partial glossectomy using the partially transection technique in the same manner as in Case 1 (Fig. 3A). Although the first suture was performed easily, we experienced difficulty while placing the second suture because of the short diameter of the duct. Then, the probe was carefully inserted into the duct, the lumen was widened by tilting the probe very gently (Fig. 3B). The following sutures could then be performed easily, assisted by the stent. Eventually, a total of 4 stitches with 7-0 Nylon were placed (Fig. 3C). Optical findings 6 months postoperatively revealed that the relocated duct was patent, and salivary secretion was present (Fig. 3D).
      Fig 3
      Fig. 3A. The duct was partially transected and a probe was inserted to expand the lumen; B. The placement of the stich was started assisted by stenting; C. A total of 4 stitches could be placed easily despite the narrowness of the duct; D. The repositioned orifice was patent 6 months postoperatively.

      3. Discussion

      The clinical significance of salivary duct repositioning remains controversial [
      • Pogrel M.A.
      Sialodochoplasty–does it work?.
      ]. Sakakibara et al. reported that submandibular duct ligation increased the complication rate significantly while parotid duct ligation or sublingual gland preservation did not, suggesting that submandibular duct repositioning should be positively undertaken [
      • Sakakibara A.
      • Minamikawa T.
      • Hashikawa K.
      • Sakakibara S.
      • Hasegawa T.
      • Akashi M.
      • et al.
      Does salivary duct repositioning prevent complications after tumor resection or salivary gland surgery?.
      ]. Ligation or incorrect repositioning of the duct, can subsequently cause stricture, obstructive sialadenitis, and swelling [
      • Ord R.A.
      • Lee V.E.
      Submandibular duct repositioning after excision of floor of mouth cancer.
      ,
      • Sakakibara A.
      • Minamikawa T.
      • Hashikawa K.
      • Sakakibara S.
      • Hasegawa T.
      • Akashi M.
      • et al.
      Does salivary duct repositioning prevent complications after tumor resection or salivary gland surgery?.
      ,
      • Pogrel M.A.
      Sialodochoplasty–does it work?.
      ,
      • Seward G.R.
      Anatomic surgery for salivary calculi. VII. Complications of salivary calculi.
      ,
      • Karas N.D.
      Surgery of the salivary ducts.
      ].
      These complications present to the clinician as a mass in the neck. Ord et al. and Sakakibara et al. indicated the requirement of further surgery due to this complication and the continued presence of a firm mass with exacerbations of pain, swelling, and infection [
      • Ord R.A.
      • Lee V.E.
      Submandibular duct repositioning after excision of floor of mouth cancer.
      ,
      • Sakakibara A.
      • Minamikawa T.
      • Hashikawa K.
      • Sakakibara S.
      • Hasegawa T.
      • Akashi M.
      • et al.
      Does salivary duct repositioning prevent complications after tumor resection or salivary gland surgery?.
      ]. In addition, duct complications arising after malignant tumor resection cannot be readily distinguished from recurrence of the tumor and metastasis to cervical lymph nodes. Removal of the gland also will violate the neck, making subsequent oncologic follow-up difficult [
      • Ord R.A.
      • Lee V.E.
      Submandibular duct repositioning after excision of floor of mouth cancer.
      ,
      • Sakakibara A.
      • Minamikawa T.
      • Hashikawa K.
      • Sakakibara S.
      • Hasegawa T.
      • Akashi M.
      • et al.
      Does salivary duct repositioning prevent complications after tumor resection or salivary gland surgery?.
      ].
      Therefore, management of the transected salivary duct is also important with regard to the oncologic follow-up.
      Very few reports have detailed the surgical procedures for salivary duct repositioning, as this operation is optional. We speculate that the challenging, yet essential, considerations for successful salivary duct repositioning are as follows: tension or distortion of the duct should not develop on transfer; the duct should be treated atraumatically [
      • Karas N.D.
      Surgery of the salivary ducts.
      ]; and the lumen of the duct needs to be sufficiently expanded to accomplish the exact suture, especially when the duct has a small diameter. These challenges can be overcome using our described techniques.
      First, the traction of the thread or the distal part (scheduled to be disconnected) of the duct enables expansion of the lumen and precise placement of the suture without directly grasping the duct directly, preventing the crushing of the duct wall. The crushed tissue might induce stenosis of the duct concomitant to postoperative cicatricial contracture. The location of the knot of the traction thread can act as a guide to prevent distortion during repositioning. Then, the appropriate placement of the first stitch is important to facilitate the placement of subsequent stitches, but its application might be very difficult in case of completely transection. With our partial transection technique, the suture can be performed under appropriate and stable tension of the duct wall produced by traction. Therefore, the first stitch becomes very easy to perform as it is placed where the distal part and the preserved part of the duct connect. Stenting also plays a significant role, especially in case of a narrow duct, as seen in case 2. The lumen can be expanded with the probe controlled by an assistant, expecting the exact stitch.
      We speculate that the postoperative obstruction of the duct despite the repositioning operation can be induced by excessive granulation tissue or scar contracture around the transferred orifice [
      • Wang W.
      • Ma Z.
      Steroid administration is effective to prevent strictures after endoscopic esophageal submucosal dissection: a network meta-analysis.
      ], distortion of the duct [
      • Ord R.A.
      • Lee V.E.
      Submandibular duct repositioning after excision of floor of mouth cancer.
      ,
      • Sakakibara A.
      • Minamikawa T.
      • Hashikawa K.
      • Sakakibara S.
      • Hasegawa T.
      • Akashi M.
      • et al.
      Does salivary duct repositioning prevent complications after tumor resection or salivary gland surgery?.
      ], and decreased salivation, among other reasons. Postoperatively, we routinely removed the fibrin-pseudomembrane forming around the orifice by a weak suction and pressed the salivary gland to accelerate salivation from the orifice. Then, the steroid ointment was applied at the repositioning site daily to suppress the excessive inflammation and granulation [
      • Wang W.
      • Ma Z.
      Steroid administration is effective to prevent strictures after endoscopic esophageal submucosal dissection: a network meta-analysis.
      ].
      When considering this technique from the perspective of tumor treatment, it should only be conducted after confirming the safety that the tumor has been properly resected.
      Successful salivary duct repositioning can prevent obstructive sialadenitis or retention cyst and contribute to a healthy environment in the head and neck region and specifically, in the oral cavity. Our approach, which is technically simple, can be accepted by all clinicians. It is a promising technique, which can contribute to effective and less invasive salivary duct repositioning.

      4. Ethical approval

      This report adheres to the tenets of the 1964 Declaration of Helsinki. Written informed consent for the publication of this report and identifiable patient photos were obtained from the patient. We asked the institutional review board and confirmed that ethics approval was not necessary for this report on basis of the ethical guidelines for medical and health research involving human subjects established by the national Ministry of Education, Culture, Sports, Science, and Technology and the Ministry of Health, Labour, and Welfare.

      Declaration of Competing Interest

      The authors declare no conflicts of interest.

      Acknowledgment

      We would like to thank Editage (www.editage.com) and Mr. Matthias Kuhn for English language editing.

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