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Surgical results of the intraoral removal of the submandibular gland
Otolaryngology–Head and Neck Surgery (2008) 139, 530-534
ORIGINAL RESEARCH— GENERAL OTOLARYNGOLOGY
Surgical results of the intraoral removal of the submandibular gland Ki Hwan Hong, MD, and Yun Su Yang, MD, Chonju, Chonbuk, Korea OBJECTIVES: Most patients with benign submandibular disorders have been treated surgically without difficulty via the transcervical approach. An alternative to the standard transcervical approach has been reported such as an intraoral approach. SUBJECTS AND METHODS: Retrospective chart review of the 77 patients with benign submandibular disorders. All patients underwent an excision of the submandibular gland via intraoral approach. RESULTS: Early postoperative complications developed in 74.0% of the temporary lingual sensory paresis followed by 70.1% of temporary limitation of tongue movement. However, these complications soon resolved in all patients spontaneously. Two cases of postoperative bleeding and 1 case of abscess formation were developed. Whereas late complications developed in 4 cases of residual salivary gland and abnormal sense of mouth floor and 1 case of gustatory sweating (Frey’s) syndrome. CONCLUSION: The major advantages of this approach are no external scar, no injury to the marginal mandibular nerve. The disadvantage is a more difficult dissection to transcervical approach before proper expert, especially in the severe adhesion of salivary gland to surrounding tissue. © 2008 American Academy of Otolaryngology–Head and Neck Surgery Foundation. All rights reserved.
C
hronic inflammatory reaction of the submandibular gland often results in irreversible histologic changes of salivary tissue. These conditions may require removal of the submandibular gland.1-3 The transcervical approach for these disorders is generally accepted, but this approach has several complications, such as a residual Wharton’s duct inflammation, a residual cyst in the floor of the mouth, and neurologic complications.4-6 Actually the Wharton’s duct could be not totally removed via the transcervical approach. The residual cyst after transcervical removal of the submandibular gland resulted from the genesis of mucocele due to injury of the sublingual gland or a mucous retention cyst due to the obliteration of the sublingual duct. The injury of the marginal mandibular nerve is a most common complication in the transcervical approach. It consists of a temporary or permanent paralysis mainly due to compression and/or stretching of the marginal mandibular nerve. The
temporary paralysis resolves spontaneously within a period of 3 months. The hypoglossal nerve injury is rare in the transcervical removal of the submandibular gland. When the hypoglossal nerve is intact, the tongue movement should be normal neurologically. However, some patients with the transcervical approach temporarily showed a mild limited movement of the tongue due to swelling of the floor of the mouth and/or injury to the extrinsic tongue muscle. This symptom completely resolved itself within the first week after surgery. In the literature review, since Downton and Qvist7 first reported an intraoral approach for chronic sialadenitis of the submandibular gland in 1960, no further reports have been found until the Hong and Kim8 report. Downton and Qvist7 made the incision on the lingual side of the necks of the teeth when the molar teeth were present. In the edentulous patients, a curved incision was made through the periosteum along the alveolus from the retromolar pad to the canine region. In their procedure, the mucoperiosteum was reflected medially, and the mylohyoid muscle was separated from its attachment to the mandible. However, Hong and Kim8 incised the mucosa on the floor of the mouth along the Wharton’s duct when the molar teeth were present, and a more lateral incision was made in the edentulous patients. The periosteal incision and separation of the mylohyoid muscle from the mandible are not necessary. Downton and Qvist7 suggested that the surgery was more difficult when the molar teeth were present, and it was sometimes necessary to make a small cervical incision simultaneously. In the Hong and Kim intraoral approach, an additional cervical incision is not necessary when the molar teeth are present. However, in the chronically inflamed disorders of the submandibular gland, the intraoral dissection of the gland is hardly performed due to the severe adhesion to the surrounding tissue, and this may alter the approach to the transcervical route. In this study, we evaluated the surgical results associated with the intraoral approach in a series of 77 operations for chronic sialadenitis and benign mixed tumors in the submandibular gland.
Received May 11, 2007; revised January 7, 2008; accepted January 23, 2008.
0194-5998/$34.00 © 2008 American Academy of Otolaryngology–Head and Neck Surgery Foundation. All rights reserved. doi:10.1016/j.otohns.2008.01.008
Hong and Yang
Surgical results of the intraoral . . .
531
SUBJECTS The age, sex, postoperative complications and long-term morbidity of 77 patients with benign submandibular disorders were reviewed for the 10 years since 1997. The simple intraoral stone removal was not included and bilateral procedures were not performed. An Institutional Review Board is not available in our institution, but we obtained proper consent from the patients in keeping with the mandate of the Declaration of Helsinki. The study’s aim, methods, and all potential risks and benefits to each patient were explained as part of the consent process. All subjects were informed of their right to abstain from participation in the study. No potential subjects were found to be legally incompetent.
SURGICAL TECHNIQUE After transnasal intubation and proper oral preparation with hydrogen dioxide and saline irrigation, the incision should be made through the mucosa of the lateral floor of the mouth from the orifice of the Wharton’s duct to the lingual side of the retromolar region (Fig 1). The sublingual gland is then dissected and totally removed with the isolation of the Wharton’s duct and preservation of the lingual nerve (Figs 2 and 3). The duct should be cut and ligated at the orifice of Wharton’s duct. The duct is isolated along the lingual nerve to the hilum of the submandibular gland. The submandibular ganglion, lying immediately inferior to the lingual nerve, can be noted by blunt dissection of the gland capsule from the surrounding tissue. With medial retraction of the tongue and floor of the mouth including the lingual nerve and lateral retraction of the mylohyoid muscle, the submandibular gland should be visible. The gland is exposed more prominently by digital pressure applied beneath the lower border of the mandible (Fig 4). For good exposure and lighting of the surgical field, the fiberoptic retractor should
Figure 1
Mucosal incision on the floor of mouth.
Figure 2 Lingual nerve and Wharton’s duct after total removal of the sublingual gland.
be used. The gland should be gripped with long tissue forceps or tonsil hemostatic forceps, dissected with the tonsil dissector or dissecting scissors, and pulled up through the incision. The loop of the facial artery and arterial branches to the gland are noted by blunt dissection and can frequently be freed completely from the gland. The artery to the submandibular gland should always be ligated or clipped with a hemoclip to prevent severe bleeding during dissection and postoperative hematoma. After removal of the submandibular gland, the hypoglossal nerve should be identified in the bed of the surgical field, and bimanual palpation should be applied to detect residual gland in the submandibular space. The incised mucosa is then sutured back loosely with silk sutures. A suction drain is inserted through the intraoral incision site and removed the first or second postoperative day according to the drain output.
Figure 3 Uncrossing the Wharton’s duct from lingual nerve submandibular gland.
532
Otolaryngology–Head and Neck Surgery, Vol 139, No 4, October 2008 Table 2 Complications after submandibular gland excision Complications
Figure 4 Dissection of submandibular gland with digital pressure and identification of facial artery or its branch to the submandibular gland.
RESULTS Thirty-four (44%) patients were male and 43 (56%) were female; the male to female ratio was 1: 1.2 (Table 1). The age of the patients ranged between 13 and 67 years, with a mean age of 36.4 years. The final diagnosis of sialolithiasis, based on the observation of sialoliths by the surgeon and/or the pathologist, was established in 47 (61.0%) cases. A previous intraoral stone removal had been performed in 9 (19%) cases among the patients with a stone. A total of 20 (25.9%) cases of sialadenitis without a stone were classified as chronic sialoadenitis. Nine (11.7%) cases of benign pleomorphic adenomas were also treated via the intraoral approach. As shown in Table 2, early postoperative complications were observed in most of the patients. A temporary lingual nerve injury (such as paresthesia of the tongue) in 57 (74.01%) cases resolved within 3 to 4 weeks in all cases; a mild limited movement of the tongue in 54 (70.1%) cases resolved within 4-6 weeks except for 2 cases. 2 cases of wound bleeding, and 2 cases of abscess formation. Late postoperative complications after 3 months appeared as
Table 1 Distributions of submandibular disorder Diagnosis Chronic sialoadenitis with stone Chronic sialoadenitis Pleomorphic adenoma Chronic sialoadenitis with ranula Total Age ranged from 13 to 67 years. Sex distributions: male 34, female 43.
Number (%) 47 20 9 1 77
(61.0) (25.9) (11.7) (1.3) (100)
Early complications Infection (abscess) Bleeding Limited tongue motion Late complication Residual duct inflammation Residual salivary tissue Unaesthetic scar Gustatory sweating Neurologic complications Mandibular nerve, temporal permanent Lingual nerve, temporal permanent Hypoglossal nerve, temporal permanent
Transcervical*
Intraoral (%)†
7.3 3.8 ?
2 (2.6) 2 (2.6) 54 (70.1)
7.3 ? 4.8 0.5
0 4 (5.2) 0 1 (1.3)
11.6 7.7 4.4 1.4
0 0 57 (74.0) 0
3.4 2.9
0 0
*Berini-Aytes and Gay-Escoda cases, 251 patients involved. †Hong and Kim cases, 77 patients involved.
follows: 4 cases of lingual paresthesia that were tolerable in all patients and resolved later, 2 cases of asymmetry of the tongue movement that were not symptomatic and only physically noted, and 4 cases of the residual salivary tissue palpated on the neck. Gustatory sweating symptom (Frey’s syndrome) was observed in 1 case. No residual inflammation in the Wharton’s duct and no external scar were noted. No injuries of the hypoglossal or marginal mandibular nerves were noted.
DISCUSSION On the surgical approach for the benign submandibular disorders, the transcervical approach is widely accepted and relatively simple, and the salivary gland tissue could be removed without difficulty and without alteration of the salivary system. However, the transcervical procedure has frequently been associated with neurologic complications after surgery, including the marginal mandibular nerve and lingual and hypoglossal nerves. Alternative surgical approaches have been developed to avoid neurologic risks and visible scarring in the upper neck. Hong and Kim8 reported a new surgical approach for intraoral removal of benign submandibular disorders and suggested that the intraoral approach could be extended as an alternative to the transcervical approach. However, this approach has also a few problems, such as temporal sensory paresis and limited movement of tongue, but resolved spontaneously, and in the
Hong and Yang
Surgical results of the intraoral . . .
severe adhesion to surrounding tissue the intraoral dissection of gland is not easily dissected. Recently, to improve cosmetic results, minimally invasive endoscopic and endorobotic methods of submandibular gland resection through various routes have been assessed in experimental9-11 and clinical studies.12,13 The operation time of endoscopic surgery, however, is significantly longer than that of other procedures. On retrospective review of the surgical data during our study period, only 11 patients were treated via the transcervical approach for the benign disorders of submandibular gland. Except for an external scar, they did not show any definite sequelae, including neurologic defects of lingual and hypoglossal nerves. Some patients showed a little asymmetry of the lower lip due to cutting of the plastysma muscle of the submandibular area; they recovered normally and were not symptomatic at all. In our study, the intraoral procedure for submandibular excision has also minor complications after surgery. Two cases of bleeding and 3 cases of infected abscess were noted. During dissection of the submandibular gland via the transcervical route, the loop of the facial artery or arterial branches to the gland should be easily noted and could frequently be freed completely from the gland. However, to demonstrate and ligate the artery to the submandibular gland in the intraoral approach may not be easy without sufficient experience.8 Experience and a detailed knowledge of the anatomy for proper dissection could reduce bleeding. In our 2 cases of postoperative bleeding, the submandibular area and floor of the mouth swelled up immediately after surgery. Bleeding was controlled during an urgent procedure in the operating room under general anesthesia. The bleeding points were branches of the facial artery and were controlled via the transcervical route in 1 patient and the intraoral route in the other patient. The intraoral approach may offer more chances for contamination from the oral cavity to the submandibular space. However, with proper preoperative preparation and continuous suction drainage with the hemovac through the oral cavity after dissection, an infection is preventable. In this intraoral approach the hypoglossal nerve should be identified at all times and never injured, but mild limitation of tongue movement was noted also with 70 percent of the patients. The swelling of the lateral tongue and floor of the mouth was observed on physical examination and resulted in temporary limited tongue movement and articulation difficulty during speech. This resolved itself within 2 weeks. However, in 2 cases, a slight limitation of tongue movement was noted physically, but not symptomatically, due to scar contracture on the floor of the mouth. The residual duct inflammation could be noted in 3 percent to 12 percent of the patients as late complications of the transcervical approach.4,14,17 The Wharton’s duct could not be removed completely in the transcervical approach, but with the intraoral approach the duct can be completely removed because the duct is cut and ligated at the orifice.
533 Therefore, the residual duct inflammation was not observed in this intraoral approach. The cause of a residual cyst in the mouth floor after the transcervical removal of the submandibular gland can be explained by the genesis of mucoceles due to injury of the sublingual gland or mucous retention cysts due to obliteration of the ducts of Rivinus. An incidence of a residual cyst can be up to 6 percent.14 This cyst can be observed mainly in the anterior floor of mouth, but sometimes in the posterior floor of mouth. In the intraoral approach, the sublingual gland should be removed totally for a proper surgical field; dissection of the submandibular gland and the residual cyst does not occur in this approach. During the transcervical dissection of the submandibular gland, the salivary tissue may be removed completely, but a small amount of salivary tissue could be left. A small amount of salivary tissue may not induce the clinical problems because of atrophy of salivary tissue.15 However, in this study, 3 patients showed a small palpable mass on the submandibular area 6 months after surgery. One patient’s mass decreased and clinically caused no problems, but 2 patients showed a protruded and reddish mass on the skin. The masses were removed via a small incision on the neck skin and showed up as salivary tissue pathologically. On retrospective review, these 3 patients underwent surgery in the beginning of our intraoral experience; at that time we were inexperienced. However, with experience, we improved our surgical technique to remove all submandibular tissue, and no further residual salivary tissue was noted. As to the aesthetic problem, the transcervical incision may induce a scar problem, especially in young women or keloid characters. However, a major advantage of this approach is the avoidance of external scarring, especially in young patients or keloid characters. The submandibular area involved appears as a little dimpling, but not distinct externally in most patients. As to neurologic complications, an injury of the mandibular branch of the facial nerve is the most common complication in the transcervical approach. Milton et al16 reported an 18 percent incidence of damage to the marginal mandibular nerve; 7 percent were permanent. It usually consists of a temporary paralysis due to a compression and/or stretching injury, which can resolve spontaneously within a period of 3 months.17 However, in the intraoral approach, the marginal mandibular nerve is not exposed during dissection, and there is no possibility of the facial nerve injury. This is also a major distinct advantage of the intraoral approach. In the transcervical approach, the lingual nerve should always be identified. Lesions associated with this nerve are not common, and if they do occur, they are temporary. A 3 percent incidence of permanent neurologic deficit was described by Milton et al,16 while Turco et al18 reported alterations of lingual sensitivity in 6 percent of cases. Goudal and Bertrand14 reported that 12 percent of the patients in their study presented neurologic sequelae, but only 4.8 percent of these were permanent. This incidence would have been higher if systematic examination had been
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Otolaryngology–Head and Neck Surgery, Vol 139, No 4, October 2008
carried out. However, in the intraoral approach, the lingual nerve is always compressed and/or stretched during traction of the floor of mouth, and the neurologic problem of lingual nerve injury was observed in most patients temporarily. Most patients showed temporary injury that lasted 2 to 3 weeks along the side of the tongue. Four patients complained of a mild reduced sense of the tongue that lasted 3 months after surgery, but resolved by long-term follow-up. The hypoglossal nerve is a critical structure that should be identified at all times3,5 in the transcervical approach and in the intraoral approach.8 The incidence of this nerve injury is rare, about 1 percent, in the transcervical approach,13 but not observed at all in the intraoral approach. Berini-Aytes and Gay-Escoda4 reported 1 case of the gustatory sweating syndrome, which resolved spontaneously. In other series, this syndrome also occurred exceptionally.16,19 In this intraoral approach, 1 case of the gustatory sweating syndrome occurred. The avoidance of this syndrome has been one of the motives cited in support of the preservation of the submandibular ganglion of the lingual nerve.15,20
CONCLUSION This intraoral approach could be extended as an alternative to the transcervical approach. The major advantages of this approach are the avoidance of an external scar and of injury to the mandibular branch of the facial nerve or the hypoglossal nerve. However, most patients temporarily complained of neurologic problems of the lingual nerve, but these were completely resolved within at least 2 months after surgery. In the severely adhered salivary gland, the intraoral dissection may not be possible, in which case, the surgical method should be altered to the complementary transcervical excision. The arterial branches to the submandibular gland should always be ligated for prevention of bleeding.
AUTHOR INFORMATION From the Department of Otolaryngology–Head and Neck Surgery, Chonbuk National University, Medical School, Chonju, Chonbuk, 561-712, Korea. Corresponding author: Ki Hwan Hong, MD, Department of Otolaryngology– Head and Neck Surgery, Chonbuk National University, Medical School Chonju, Chonbuk, 560-182, Republic of Korea. E-mail address: [email protected].
AUTHOR CONTRIBUTION Ki Hwan Hong, study design and writer; Yun Su Yang, data collection.
FINANCIAL DISCLOSURE None.
REFERENCES 1. van den Akker HP, Besemann-Sokole E. Submandibular gland function following transoral sialolithectomy. Oral Surg 1983;56:351– 6. 2. Isacsson G, Isberg A, Haverling M, et al. Salivary calculi and chronic sialoadenitis of the submandibular gland: a radiographic and histologic study. Oral Surg 1984;58:622–7. 3. Beahrs OH, Woolner LB. Surgical treatment of diseases of salivary gland. Oral Surg 1969;27:119 –28. 4. Berini-Aytes L, Gay-Escoda C. Morbidity associated with removal of the submandibular gland. J Craniomaxillofac Surg 1992;20:216 –9. 5. Eichel BS, Bray DA, Kaplan HJ, et al. The overall management of salivary gland disorders. Laryngoscope 1981;91:504 –11. 6. Blatt I. Inflammation of the salivary glands. Laryngoscope 1966;76: 917–33. 7. Downton D, Qvist G. Intraoral excision of the submandibular gland. Proceedings of the Royal Society of Medicine 1960;53:543– 4. 8. Hong KH, Kim YK. Intraoral removal of the submandibular gland: a new surgical approach. Otolaryngol Head Neck Surg 2000;122:798 – 802. 9. Monfared Y, Saenz Y, Terris DJ. Endoscopic resection of the submandibular gland in a porcine model. Laryngoscope 2002;112: 1089 –93. 10. Guyot L, Duroure F, Richard O, et al. Submandibular gland endoscopic resection: a cadaveric study. Int J Oral Maxillofac Surg 2005; 34:407–10. 11. Terris DJ, Haus BM, Gourin CG, et al. Endo-robotic resection of the submandibular gland in a cadaver model. Head Neck 2005;27:946 –51. 12. Chen MK, Su CC, Tsai YL, et al. Minimally invasive endoscopic resection of the submandibular gland: a new approach. Head Neck 2006;28:1014 –7. 13. Roh JL. Removal of the submandibular gland by a retroauricular approach. Arch Otolaryngol Head Neck Surg 2006;132:783–7. 14. Goudal JY, Bertrand JC. [Complications of surgical treatment for submandibular calculi]. Rev Stomatol Chir Maxillofac 1979;80: 349 –50. 15. Yoel J. Pathology and surgery of the salivary glands, 3rd ed. Springfield, IL: Charles C Thomas Publisher; 1975. pp. 820 –1136. 16. Milton CM, Thomas BM, Bikerton RC. Morbidity study of submandibular gland excision. Ann R Coll Surg Engl 1986;68:148 –50. 17. Marynard J. Contemporary surgery: submandibular and parotid resection. Br J Hosp Med 1978;20:70. 18. Turco C, Nision A, Brunetti F. [Submandibular sialoadenectomy and long-term results]. Minerva Stomatol 1988;37:329 –33. 19. Bailey BM, Pearce DE. Gustatory sweating following submandibular salivary gland removal. Br Dent J 1985;158:17– 8. 20. Rankow RM, Polayes IM. Inflammatory disorders. Surgical management. In: Rankow and Polayes: Diseases of the salivary glands. Philadelphia: WB Saunders; 1976. pp. 229-38.
ORIGINAL RESEARCH— GENERAL OTOLARYNGOLOGY
Surgical results of the intraoral removal of the submandibular gland Ki Hwan Hong, MD, and Yun Su Yang, MD, Chonju, Chonbuk, Korea OBJECTIVES: Most patients with benign submandibular disorders have been treated surgically without difficulty via the transcervical approach. An alternative to the standard transcervical approach has been reported such as an intraoral approach. SUBJECTS AND METHODS: Retrospective chart review of the 77 patients with benign submandibular disorders. All patients underwent an excision of the submandibular gland via intraoral approach. RESULTS: Early postoperative complications developed in 74.0% of the temporary lingual sensory paresis followed by 70.1% of temporary limitation of tongue movement. However, these complications soon resolved in all patients spontaneously. Two cases of postoperative bleeding and 1 case of abscess formation were developed. Whereas late complications developed in 4 cases of residual salivary gland and abnormal sense of mouth floor and 1 case of gustatory sweating (Frey’s) syndrome. CONCLUSION: The major advantages of this approach are no external scar, no injury to the marginal mandibular nerve. The disadvantage is a more difficult dissection to transcervical approach before proper expert, especially in the severe adhesion of salivary gland to surrounding tissue. © 2008 American Academy of Otolaryngology–Head and Neck Surgery Foundation. All rights reserved.
C
hronic inflammatory reaction of the submandibular gland often results in irreversible histologic changes of salivary tissue. These conditions may require removal of the submandibular gland.1-3 The transcervical approach for these disorders is generally accepted, but this approach has several complications, such as a residual Wharton’s duct inflammation, a residual cyst in the floor of the mouth, and neurologic complications.4-6 Actually the Wharton’s duct could be not totally removed via the transcervical approach. The residual cyst after transcervical removal of the submandibular gland resulted from the genesis of mucocele due to injury of the sublingual gland or a mucous retention cyst due to the obliteration of the sublingual duct. The injury of the marginal mandibular nerve is a most common complication in the transcervical approach. It consists of a temporary or permanent paralysis mainly due to compression and/or stretching of the marginal mandibular nerve. The
temporary paralysis resolves spontaneously within a period of 3 months. The hypoglossal nerve injury is rare in the transcervical removal of the submandibular gland. When the hypoglossal nerve is intact, the tongue movement should be normal neurologically. However, some patients with the transcervical approach temporarily showed a mild limited movement of the tongue due to swelling of the floor of the mouth and/or injury to the extrinsic tongue muscle. This symptom completely resolved itself within the first week after surgery. In the literature review, since Downton and Qvist7 first reported an intraoral approach for chronic sialadenitis of the submandibular gland in 1960, no further reports have been found until the Hong and Kim8 report. Downton and Qvist7 made the incision on the lingual side of the necks of the teeth when the molar teeth were present. In the edentulous patients, a curved incision was made through the periosteum along the alveolus from the retromolar pad to the canine region. In their procedure, the mucoperiosteum was reflected medially, and the mylohyoid muscle was separated from its attachment to the mandible. However, Hong and Kim8 incised the mucosa on the floor of the mouth along the Wharton’s duct when the molar teeth were present, and a more lateral incision was made in the edentulous patients. The periosteal incision and separation of the mylohyoid muscle from the mandible are not necessary. Downton and Qvist7 suggested that the surgery was more difficult when the molar teeth were present, and it was sometimes necessary to make a small cervical incision simultaneously. In the Hong and Kim intraoral approach, an additional cervical incision is not necessary when the molar teeth are present. However, in the chronically inflamed disorders of the submandibular gland, the intraoral dissection of the gland is hardly performed due to the severe adhesion to the surrounding tissue, and this may alter the approach to the transcervical route. In this study, we evaluated the surgical results associated with the intraoral approach in a series of 77 operations for chronic sialadenitis and benign mixed tumors in the submandibular gland.
Received May 11, 2007; revised January 7, 2008; accepted January 23, 2008.
0194-5998/$34.00 © 2008 American Academy of Otolaryngology–Head and Neck Surgery Foundation. All rights reserved. doi:10.1016/j.otohns.2008.01.008
Hong and Yang
Surgical results of the intraoral . . .
531
SUBJECTS The age, sex, postoperative complications and long-term morbidity of 77 patients with benign submandibular disorders were reviewed for the 10 years since 1997. The simple intraoral stone removal was not included and bilateral procedures were not performed. An Institutional Review Board is not available in our institution, but we obtained proper consent from the patients in keeping with the mandate of the Declaration of Helsinki. The study’s aim, methods, and all potential risks and benefits to each patient were explained as part of the consent process. All subjects were informed of their right to abstain from participation in the study. No potential subjects were found to be legally incompetent.
SURGICAL TECHNIQUE After transnasal intubation and proper oral preparation with hydrogen dioxide and saline irrigation, the incision should be made through the mucosa of the lateral floor of the mouth from the orifice of the Wharton’s duct to the lingual side of the retromolar region (Fig 1). The sublingual gland is then dissected and totally removed with the isolation of the Wharton’s duct and preservation of the lingual nerve (Figs 2 and 3). The duct should be cut and ligated at the orifice of Wharton’s duct. The duct is isolated along the lingual nerve to the hilum of the submandibular gland. The submandibular ganglion, lying immediately inferior to the lingual nerve, can be noted by blunt dissection of the gland capsule from the surrounding tissue. With medial retraction of the tongue and floor of the mouth including the lingual nerve and lateral retraction of the mylohyoid muscle, the submandibular gland should be visible. The gland is exposed more prominently by digital pressure applied beneath the lower border of the mandible (Fig 4). For good exposure and lighting of the surgical field, the fiberoptic retractor should
Figure 1
Mucosal incision on the floor of mouth.
Figure 2 Lingual nerve and Wharton’s duct after total removal of the sublingual gland.
be used. The gland should be gripped with long tissue forceps or tonsil hemostatic forceps, dissected with the tonsil dissector or dissecting scissors, and pulled up through the incision. The loop of the facial artery and arterial branches to the gland are noted by blunt dissection and can frequently be freed completely from the gland. The artery to the submandibular gland should always be ligated or clipped with a hemoclip to prevent severe bleeding during dissection and postoperative hematoma. After removal of the submandibular gland, the hypoglossal nerve should be identified in the bed of the surgical field, and bimanual palpation should be applied to detect residual gland in the submandibular space. The incised mucosa is then sutured back loosely with silk sutures. A suction drain is inserted through the intraoral incision site and removed the first or second postoperative day according to the drain output.
Figure 3 Uncrossing the Wharton’s duct from lingual nerve submandibular gland.
532
Otolaryngology–Head and Neck Surgery, Vol 139, No 4, October 2008 Table 2 Complications after submandibular gland excision Complications
Figure 4 Dissection of submandibular gland with digital pressure and identification of facial artery or its branch to the submandibular gland.
RESULTS Thirty-four (44%) patients were male and 43 (56%) were female; the male to female ratio was 1: 1.2 (Table 1). The age of the patients ranged between 13 and 67 years, with a mean age of 36.4 years. The final diagnosis of sialolithiasis, based on the observation of sialoliths by the surgeon and/or the pathologist, was established in 47 (61.0%) cases. A previous intraoral stone removal had been performed in 9 (19%) cases among the patients with a stone. A total of 20 (25.9%) cases of sialadenitis without a stone were classified as chronic sialoadenitis. Nine (11.7%) cases of benign pleomorphic adenomas were also treated via the intraoral approach. As shown in Table 2, early postoperative complications were observed in most of the patients. A temporary lingual nerve injury (such as paresthesia of the tongue) in 57 (74.01%) cases resolved within 3 to 4 weeks in all cases; a mild limited movement of the tongue in 54 (70.1%) cases resolved within 4-6 weeks except for 2 cases. 2 cases of wound bleeding, and 2 cases of abscess formation. Late postoperative complications after 3 months appeared as
Table 1 Distributions of submandibular disorder Diagnosis Chronic sialoadenitis with stone Chronic sialoadenitis Pleomorphic adenoma Chronic sialoadenitis with ranula Total Age ranged from 13 to 67 years. Sex distributions: male 34, female 43.
Number (%) 47 20 9 1 77
(61.0) (25.9) (11.7) (1.3) (100)
Early complications Infection (abscess) Bleeding Limited tongue motion Late complication Residual duct inflammation Residual salivary tissue Unaesthetic scar Gustatory sweating Neurologic complications Mandibular nerve, temporal permanent Lingual nerve, temporal permanent Hypoglossal nerve, temporal permanent
Transcervical*
Intraoral (%)†
7.3 3.8 ?
2 (2.6) 2 (2.6) 54 (70.1)
7.3 ? 4.8 0.5
0 4 (5.2) 0 1 (1.3)
11.6 7.7 4.4 1.4
0 0 57 (74.0) 0
3.4 2.9
0 0
*Berini-Aytes and Gay-Escoda cases, 251 patients involved. †Hong and Kim cases, 77 patients involved.
follows: 4 cases of lingual paresthesia that were tolerable in all patients and resolved later, 2 cases of asymmetry of the tongue movement that were not symptomatic and only physically noted, and 4 cases of the residual salivary tissue palpated on the neck. Gustatory sweating symptom (Frey’s syndrome) was observed in 1 case. No residual inflammation in the Wharton’s duct and no external scar were noted. No injuries of the hypoglossal or marginal mandibular nerves were noted.
DISCUSSION On the surgical approach for the benign submandibular disorders, the transcervical approach is widely accepted and relatively simple, and the salivary gland tissue could be removed without difficulty and without alteration of the salivary system. However, the transcervical procedure has frequently been associated with neurologic complications after surgery, including the marginal mandibular nerve and lingual and hypoglossal nerves. Alternative surgical approaches have been developed to avoid neurologic risks and visible scarring in the upper neck. Hong and Kim8 reported a new surgical approach for intraoral removal of benign submandibular disorders and suggested that the intraoral approach could be extended as an alternative to the transcervical approach. However, this approach has also a few problems, such as temporal sensory paresis and limited movement of tongue, but resolved spontaneously, and in the
Hong and Yang
Surgical results of the intraoral . . .
severe adhesion to surrounding tissue the intraoral dissection of gland is not easily dissected. Recently, to improve cosmetic results, minimally invasive endoscopic and endorobotic methods of submandibular gland resection through various routes have been assessed in experimental9-11 and clinical studies.12,13 The operation time of endoscopic surgery, however, is significantly longer than that of other procedures. On retrospective review of the surgical data during our study period, only 11 patients were treated via the transcervical approach for the benign disorders of submandibular gland. Except for an external scar, they did not show any definite sequelae, including neurologic defects of lingual and hypoglossal nerves. Some patients showed a little asymmetry of the lower lip due to cutting of the plastysma muscle of the submandibular area; they recovered normally and were not symptomatic at all. In our study, the intraoral procedure for submandibular excision has also minor complications after surgery. Two cases of bleeding and 3 cases of infected abscess were noted. During dissection of the submandibular gland via the transcervical route, the loop of the facial artery or arterial branches to the gland should be easily noted and could frequently be freed completely from the gland. However, to demonstrate and ligate the artery to the submandibular gland in the intraoral approach may not be easy without sufficient experience.8 Experience and a detailed knowledge of the anatomy for proper dissection could reduce bleeding. In our 2 cases of postoperative bleeding, the submandibular area and floor of the mouth swelled up immediately after surgery. Bleeding was controlled during an urgent procedure in the operating room under general anesthesia. The bleeding points were branches of the facial artery and were controlled via the transcervical route in 1 patient and the intraoral route in the other patient. The intraoral approach may offer more chances for contamination from the oral cavity to the submandibular space. However, with proper preoperative preparation and continuous suction drainage with the hemovac through the oral cavity after dissection, an infection is preventable. In this intraoral approach the hypoglossal nerve should be identified at all times and never injured, but mild limitation of tongue movement was noted also with 70 percent of the patients. The swelling of the lateral tongue and floor of the mouth was observed on physical examination and resulted in temporary limited tongue movement and articulation difficulty during speech. This resolved itself within 2 weeks. However, in 2 cases, a slight limitation of tongue movement was noted physically, but not symptomatically, due to scar contracture on the floor of the mouth. The residual duct inflammation could be noted in 3 percent to 12 percent of the patients as late complications of the transcervical approach.4,14,17 The Wharton’s duct could not be removed completely in the transcervical approach, but with the intraoral approach the duct can be completely removed because the duct is cut and ligated at the orifice.
533 Therefore, the residual duct inflammation was not observed in this intraoral approach. The cause of a residual cyst in the mouth floor after the transcervical removal of the submandibular gland can be explained by the genesis of mucoceles due to injury of the sublingual gland or mucous retention cysts due to obliteration of the ducts of Rivinus. An incidence of a residual cyst can be up to 6 percent.14 This cyst can be observed mainly in the anterior floor of mouth, but sometimes in the posterior floor of mouth. In the intraoral approach, the sublingual gland should be removed totally for a proper surgical field; dissection of the submandibular gland and the residual cyst does not occur in this approach. During the transcervical dissection of the submandibular gland, the salivary tissue may be removed completely, but a small amount of salivary tissue could be left. A small amount of salivary tissue may not induce the clinical problems because of atrophy of salivary tissue.15 However, in this study, 3 patients showed a small palpable mass on the submandibular area 6 months after surgery. One patient’s mass decreased and clinically caused no problems, but 2 patients showed a protruded and reddish mass on the skin. The masses were removed via a small incision on the neck skin and showed up as salivary tissue pathologically. On retrospective review, these 3 patients underwent surgery in the beginning of our intraoral experience; at that time we were inexperienced. However, with experience, we improved our surgical technique to remove all submandibular tissue, and no further residual salivary tissue was noted. As to the aesthetic problem, the transcervical incision may induce a scar problem, especially in young women or keloid characters. However, a major advantage of this approach is the avoidance of external scarring, especially in young patients or keloid characters. The submandibular area involved appears as a little dimpling, but not distinct externally in most patients. As to neurologic complications, an injury of the mandibular branch of the facial nerve is the most common complication in the transcervical approach. Milton et al16 reported an 18 percent incidence of damage to the marginal mandibular nerve; 7 percent were permanent. It usually consists of a temporary paralysis due to a compression and/or stretching injury, which can resolve spontaneously within a period of 3 months.17 However, in the intraoral approach, the marginal mandibular nerve is not exposed during dissection, and there is no possibility of the facial nerve injury. This is also a major distinct advantage of the intraoral approach. In the transcervical approach, the lingual nerve should always be identified. Lesions associated with this nerve are not common, and if they do occur, they are temporary. A 3 percent incidence of permanent neurologic deficit was described by Milton et al,16 while Turco et al18 reported alterations of lingual sensitivity in 6 percent of cases. Goudal and Bertrand14 reported that 12 percent of the patients in their study presented neurologic sequelae, but only 4.8 percent of these were permanent. This incidence would have been higher if systematic examination had been
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Otolaryngology–Head and Neck Surgery, Vol 139, No 4, October 2008
carried out. However, in the intraoral approach, the lingual nerve is always compressed and/or stretched during traction of the floor of mouth, and the neurologic problem of lingual nerve injury was observed in most patients temporarily. Most patients showed temporary injury that lasted 2 to 3 weeks along the side of the tongue. Four patients complained of a mild reduced sense of the tongue that lasted 3 months after surgery, but resolved by long-term follow-up. The hypoglossal nerve is a critical structure that should be identified at all times3,5 in the transcervical approach and in the intraoral approach.8 The incidence of this nerve injury is rare, about 1 percent, in the transcervical approach,13 but not observed at all in the intraoral approach. Berini-Aytes and Gay-Escoda4 reported 1 case of the gustatory sweating syndrome, which resolved spontaneously. In other series, this syndrome also occurred exceptionally.16,19 In this intraoral approach, 1 case of the gustatory sweating syndrome occurred. The avoidance of this syndrome has been one of the motives cited in support of the preservation of the submandibular ganglion of the lingual nerve.15,20
CONCLUSION This intraoral approach could be extended as an alternative to the transcervical approach. The major advantages of this approach are the avoidance of an external scar and of injury to the mandibular branch of the facial nerve or the hypoglossal nerve. However, most patients temporarily complained of neurologic problems of the lingual nerve, but these were completely resolved within at least 2 months after surgery. In the severely adhered salivary gland, the intraoral dissection may not be possible, in which case, the surgical method should be altered to the complementary transcervical excision. The arterial branches to the submandibular gland should always be ligated for prevention of bleeding.
AUTHOR INFORMATION From the Department of Otolaryngology–Head and Neck Surgery, Chonbuk National University, Medical School, Chonju, Chonbuk, 561-712, Korea. Corresponding author: Ki Hwan Hong, MD, Department of Otolaryngology– Head and Neck Surgery, Chonbuk National University, Medical School Chonju, Chonbuk, 560-182, Republic of Korea. E-mail address: [email protected].
AUTHOR CONTRIBUTION Ki Hwan Hong, study design and writer; Yun Su Yang, data collection.
FINANCIAL DISCLOSURE None.
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