Because of its relatively small caliber lumen, traumatic injuries of the parotid duct appropriately lend themselves to microsurgical repair. With the evolution of more modern techniques and materials, inert nylon microsutures placed under magnification permit an ideal atraumatic anastomosis of the divided ends of the parotid duct. Such an exact approach may also obviate the need for long-term stenting across the site of repair, which remains a controversial issue. o 1992 wiley-Liss, Inc. MICROSURGERY 13243-248
1992
MICROSURGICAL REPAIR OF THE PAROTID DUCT GEOFFREY G. HALLOCK, M.D.
Injuries of the parotid duct are uncommon. ‘-3 Although SURGICAL ANATOMY better recognized and treated today, prior to 1947 only eight The parotid duct arises from the anterolateral parotid cases of parotid duct repair had been reported,4 Because of gland3 and passes about 1 cm below the zygoma across the the propinquity of the buccal and zygomatic plexus of the masseter muscle and buccal fat pad.” At the anterior border facial nerve to the duct, drooping of the upper lip implies a of the masseter muscle, the duct turns to proceed deeply and concomitant injury and clue in making this diagn~sis.”~penetrate the buccinator muscle, finally ending intraorally Appropriate treatment varies, depending on the site of in- at Stensen’s duct opposite the second upper molar tooth.” jury along the course of the parotid duct.’,’ Duct ligation if This corresponds to a line drawn from the tragus of the ear injured in the glandular portion, or oral reimplantation prox- to the midpoint of the upper lip, whose central one-third imal to Stensen’s duct for distal lacerations are reasonable represents the zone over the masseter muscle, where the options if primary reanastomosis of the divided ends is im- duct is most amenable for a direct repair.’,’ Within this possible, although the superiority of any one of these tech- same plane, the lower buccal branches of the facial nerve niques has never been objectively proven. parallel or sometimes obliquely cross the parotid duct such From a functional standpoint, the goal of any method of that they too are vulnerable if the latter is parotid duct reconstruction is to maintain patency and to The walls of the duct are thick and fibrous which makes ensure free salivary flow.8 Current authoritative textbooks them resistant to c o l l a p ~ eThe . ~ outer diameter may be up to still recommend large caliber silk sutures and indwelling 5 mm12 (Fig. l ) , but the inner diameter is much less (Fig. stents for up to 2 weeks.539At the opposite extreme, less 2). The duct is 6-7 cm long such that extensive mobilizatraumatic, inert nylon microsutures placed using the oper- tion over the masseter muscle is p ~ s s i b l e . ~ ating microscope have also been advocated. ‘,lo Long-term stenting of the anastomosis has in addition been questioned, since many reports of accidental early dislodging or omis- TECHNIQUE sion altogether of a catheter have had no serious Through existing wounds or an extension of the site of s e q ~ e l a . ~ ~Since ’ ~ ” the internal diameter of the parotid duct fistulization, the proximal end of a divided duct may be may be only a few millimeters, logically an ideal repair identified by the secretion of clear saliva. The distal end, if should be possible under microscopic magnification using not readily apparent, requires a small lacrimal dilator or small sutures that cause minimal iatrogenic damage and similar probing through Stensen’s duct in retrograde fashproper mucosal apposition, thereby obviating any need for ion, retracting the cheek posteriorly to simplify its internal splinting of the duct. in~ertion.~ Mobilization of the duct facilitates approximation for repair using the same microclamps normally used in microvascular procedures (Fig. 2). At this time, any divided facial nerve branches are also identified to facilitate later From the Division of Plastic Surgery, Lehigh Valley Hospital, Allentown, Pennmicroneural repair. sylvania. Temporary use of a plastic stent in the lumen of the Acknowledgments: Microsurgical assistance was provided by David C. Rice, divided duct ends may prevent inadvertent placement of B.S., Director of the Dorothy Rider Pool Microsurgical and Laser Laboratory, backwall stitches. Magnification under the operating microLehigh Valley Hospital, Allentown, Pennsylvania. scope permits adequate debridement of all injured layers of Address reprint requests to Dr. Geoffrey 0. Hallock, 1230 South Cedar Crest Boulevard, Suite 308.Allentown, PA 18103. the parotid duct and exact placement of every suture to ensure inclusion of the mucous membrane lining by each. Received for publication. March 25, 1992.
’,’
0 1992 Wiley-Liss. Inc.
244
Hallock
Figure 1. Retrieved ends of divided parotid duct (black arrow) with a 3- to 4-mm outer diameter. Concomitantly injured buccal branch of facial newe also identified (white arrow).
Figure 2. Approximating microclamp facilitates end-to-end microanastomosis of the parotid duct. A l -mm plastic stent occupies and almost fillsthe lumen.
Using any acceptable microsurgical approach, atraumatic 9-0 or 10-0 simple, interrupted nylon sutures are positioned as needed. After completion of the anterior wall, the microclamps are rotated and the posterior wall similarly repaired. The stent may be left protruding from Stensen's duct or removed as desired. The overlying tissues are closed in layers which decreases the risk of reoperation if a small fistula would complicate the procedure.
observed. A branch of the facial nerve was also repaired. At 24 hr, the patient pulled out his stent that had been passed through Stensen's duct and taped to his cheek. Nevertheless, he had instantaneous cessation of all salivary leakage down his cheek with no late evidence of sialocele or other complication. At one year, facial muscle function was improved (Fig. 3,with no recurrence of the presenting complaints. He agreed to have a sialogram performed. Narrowing was noted at a site consistent with the anastomosis, but filling of parotid gland radicles was not obstructed (Fig. 6).
CASE REPORTS Case 1 Delayed repair of parotid fistula. A 27-year-old man involved in an altercation suffered a vertical laceration across the mid-portion of his left cheek closed elsewhere (Fig. 3). Inability to elevate his left upper lip was noted (Fig. 4). His major complaint was that for the 2 weeks since injury, copious clear fluid was draining from the wound. This was soaking the diaper that he had to wear around his neck (Fig. 3). Intraoperative wound exploration following the path of the saliva immediately allowed identification of both ends of the divided parotid duct overlying the masseter muscle (Fig. 1). This was repaired over a stent using 9 - 0 nylon sutures and the operating microscope (Fig. 2). No leak was
Case 2 Immediate repair of iatrogenic parotid duct laceration. A 48-year-old woman underwent cosmetic rhyti-
dectomy. During blunt elevation of the deeper superficial musculoaponeurotic system (SMAS) layer anterior to the parotid gland, inadvertent injury to the right parotid duct and a small adjacent branch of the facial nerve was recognized, a known risk of this di~section.'~ Both were repaired using 10-0 nylon sutures with the operating microscope. No unusual facial swelling nor facial paralysis was noted in the immediate postoperative period. No stent was placed in the parotid duct. At one year follow-up, she is content with
Microsurgery of the Parotid Duct
Figure 3. Location of vertical left mid-cheek laceration should arouse a high degree of suspicion of a parotid duct injury. The diaper around his neck was to collect the huge volume of salivary discharge from the cutaneous fistula.
245
c o m e , this is a clue that simultaneous injury to the parotid duct has also occurred. Figure 5. One year later, grimace is markedly improved, and no drip pad is employed.
Figure 4. Paresis of the left upper lip due to injury of the facial nerve branch as shown in Figure 7. Because of theirjuxtaposedanatomical
her facial appearance and had no complaints referable to her untoward parotid duct injury. Because of an iodine allergy, she declined a sialogram. DISCUSSION
The opportunity to repair a parotid duct injury is not a commonplace event, as these two cases represent my entire experience over the past 10 years. In order to preserve parotid gland function, it would seem reasonable from the experience of others to attempt reanastomosis of the divided ends of the duct.’-3,7,8 The means to do this, however, is the point of contention. Classical dictums as to the choice of suture material, the need for stenting of the repair, and the use of magnification need to be ~hallenged.~.’ All types of suture materials have been used to repair the parotid Absorbable sutures may dissolve too soon or may create an inflammatory reaction, as does silk, which on at least one occasion has been incriminated as the cause of a postoperative leak leading to cutaneous fistulization.’ This was in contradistinction to all other repairs by the same surgeon where he had no complications if small-caliber inert nylon sutures were used.2 Others also have used 10-0 nylon microsutures with proven success. loupe magnification may be adequate,’ the operating microscope facilitates the handling of such small sutures as well as providing better visualiza-
Figure 6. Although asymptomatic, the patient in case 7 agreed to a sia/wram. Narrowing is noted corresponding to the site of microanastomoses, but parofid gland radicles freely fill beyond this.
246
Hallock
tion of the mucosal lining of the parotid duct, whose internal diameter can be less than a few millimeters'.'0 (Fig. 2). REFERENCES The role of a stent across any parotid duct anastomosis 1. Tachmes L, Woloszyn T, Marini C, Coons M, Eastlick L, Shaftan G, is less clear. For small blood vessels, this technique is Saltzman EI: Parotid gland and facial nerve trauma: A retrospective review. J Trauma 30:1395-1398, 1990. known to allow better exposure of the intima14and certainly Stevenson JH: Parotid duct transection associated with facial trauma: provided this advantage as documented in Case 1. Stricture 2. Experience with 10 cases. Br J Plast Surg 36231-82, 1983. from subsequent edema is theoretically avoided by a space 3. Barton NW, Miller SH, Graham W P Managing lacerations of the parotid gland, duct and facial nerve. Am F m Physician 12130-134. occupying Yet, stenosis of the parotid duct has oc1976. curred even with an indwelling splint.' Schultz stents total 4. Bornstein LA, Simon BE: Successful primary repair of severed paparotid duct lacerations 5-7 days but removes it immedirotid duct. Plast Reconsrr Surg 6:217-227, 1950. 5 . Schulb RC: Soft tissue injuries of the face, in Smith JW, Aston SJ ately after repair of a partial p ace ration.^ Others stent all (eds): Grubb and Smith's Plastic Surgery. 4th Ed. Boston, Little, repairs anywhere up to 2 week^.'*^*^^'^^'^ In many cases, Brown, 1991, pp 336-337. the stent has been removed during the original anaesthesia 6. Rudolph R: Depth of the facial nerve in face lift dissections. Plast Reconstr Surg 85537-544, 1990. or inadvertently dislodged immediately thereafter with no 7. Kitamura T, Togawa K: Surgery of Stensen's duct. Arch Otolaryngnl untoward sequela.2*11The thick fibrous anatomy of the pa93:189-193, 1971. rotid duct wall inherently reduces the risk of collapse and 8. Halsband ER, Doku HC, Maloney P L Parotid duct laceration: Report of cases. J Oral Surg 28:123-124, 1970. therefore also makes the need for postoperative anastomotic 9. Manson PN: Facial injuries, in McCarthy JG, (ed): Plastic Surgery, support to ensure patency less compel~ing.~ Vol. 2, Philadelphia, WB Saunders, 1990, pp 906-908. No series has been, or may ever be, large enough to 10 Holt GR, Holt JE: Lacerations of the lacrimal apparatus, parotid duct, and facial nerve: Case report. J T r a m 16:414-419, 1976. prospectively provide an answer to all these variables. With the advent of microsurgical equipment and technique, and 11. DeVylder J, Carlo J, Stratigos GT: Early recognition and treatment of the traumatically transected parotid duct: Report of case. J Oral Surg our knowledge of the effects of small inert sutures on heal36:43-44, 1978. ing of the microvasculature, it seems reasonable to extrap- 12. Woodburne R T Essentials of Human Anatomy, 4th Ed. New York, Oxford University Press, 1969, pp 205-207. olate the benefits of this approach for the repair of the 13. Bansberg SF, Krugman ME: Parotid salivary fistula following rhytilacerated parotid duct as well. The use of microsuture with dectomy. Ann Plast Surg 2461-62, 1990. the magnification provided by the operating microscope 14. Cong Z, Nongxuan T, Changfu Z, Yuanwei X, Tongde W: Experimental study on microvascular anastomosis using a dissolvable stent permits a superior anastomosis that may also eliminate the support in the lumen. Microsurgery 12:67-71, 1991. need and inconvenience of postoperative cannulation of the 15. Abramson M: Treatment of parotid duct injuries. hryngoscope 83: parotid duct. 1764-1768, 1973.
1992
MICROSURGICAL REPAIR OF THE PAROTID DUCT GEOFFREY G. HALLOCK, M.D.
Injuries of the parotid duct are uncommon. ‘-3 Although SURGICAL ANATOMY better recognized and treated today, prior to 1947 only eight The parotid duct arises from the anterolateral parotid cases of parotid duct repair had been reported,4 Because of gland3 and passes about 1 cm below the zygoma across the the propinquity of the buccal and zygomatic plexus of the masseter muscle and buccal fat pad.” At the anterior border facial nerve to the duct, drooping of the upper lip implies a of the masseter muscle, the duct turns to proceed deeply and concomitant injury and clue in making this diagn~sis.”~penetrate the buccinator muscle, finally ending intraorally Appropriate treatment varies, depending on the site of in- at Stensen’s duct opposite the second upper molar tooth.” jury along the course of the parotid duct.’,’ Duct ligation if This corresponds to a line drawn from the tragus of the ear injured in the glandular portion, or oral reimplantation prox- to the midpoint of the upper lip, whose central one-third imal to Stensen’s duct for distal lacerations are reasonable represents the zone over the masseter muscle, where the options if primary reanastomosis of the divided ends is im- duct is most amenable for a direct repair.’,’ Within this possible, although the superiority of any one of these tech- same plane, the lower buccal branches of the facial nerve niques has never been objectively proven. parallel or sometimes obliquely cross the parotid duct such From a functional standpoint, the goal of any method of that they too are vulnerable if the latter is parotid duct reconstruction is to maintain patency and to The walls of the duct are thick and fibrous which makes ensure free salivary flow.8 Current authoritative textbooks them resistant to c o l l a p ~ eThe . ~ outer diameter may be up to still recommend large caliber silk sutures and indwelling 5 mm12 (Fig. l ) , but the inner diameter is much less (Fig. stents for up to 2 weeks.539At the opposite extreme, less 2). The duct is 6-7 cm long such that extensive mobilizatraumatic, inert nylon microsutures placed using the oper- tion over the masseter muscle is p ~ s s i b l e . ~ ating microscope have also been advocated. ‘,lo Long-term stenting of the anastomosis has in addition been questioned, since many reports of accidental early dislodging or omis- TECHNIQUE sion altogether of a catheter have had no serious Through existing wounds or an extension of the site of s e q ~ e l a . ~ ~Since ’ ~ ” the internal diameter of the parotid duct fistulization, the proximal end of a divided duct may be may be only a few millimeters, logically an ideal repair identified by the secretion of clear saliva. The distal end, if should be possible under microscopic magnification using not readily apparent, requires a small lacrimal dilator or small sutures that cause minimal iatrogenic damage and similar probing through Stensen’s duct in retrograde fashproper mucosal apposition, thereby obviating any need for ion, retracting the cheek posteriorly to simplify its internal splinting of the duct. in~ertion.~ Mobilization of the duct facilitates approximation for repair using the same microclamps normally used in microvascular procedures (Fig. 2). At this time, any divided facial nerve branches are also identified to facilitate later From the Division of Plastic Surgery, Lehigh Valley Hospital, Allentown, Pennmicroneural repair. sylvania. Temporary use of a plastic stent in the lumen of the Acknowledgments: Microsurgical assistance was provided by David C. Rice, divided duct ends may prevent inadvertent placement of B.S., Director of the Dorothy Rider Pool Microsurgical and Laser Laboratory, backwall stitches. Magnification under the operating microLehigh Valley Hospital, Allentown, Pennsylvania. scope permits adequate debridement of all injured layers of Address reprint requests to Dr. Geoffrey 0. Hallock, 1230 South Cedar Crest Boulevard, Suite 308.Allentown, PA 18103. the parotid duct and exact placement of every suture to ensure inclusion of the mucous membrane lining by each. Received for publication. March 25, 1992.
’,’
0 1992 Wiley-Liss. Inc.
244
Hallock
Figure 1. Retrieved ends of divided parotid duct (black arrow) with a 3- to 4-mm outer diameter. Concomitantly injured buccal branch of facial newe also identified (white arrow).
Figure 2. Approximating microclamp facilitates end-to-end microanastomosis of the parotid duct. A l -mm plastic stent occupies and almost fillsthe lumen.
Using any acceptable microsurgical approach, atraumatic 9-0 or 10-0 simple, interrupted nylon sutures are positioned as needed. After completion of the anterior wall, the microclamps are rotated and the posterior wall similarly repaired. The stent may be left protruding from Stensen's duct or removed as desired. The overlying tissues are closed in layers which decreases the risk of reoperation if a small fistula would complicate the procedure.
observed. A branch of the facial nerve was also repaired. At 24 hr, the patient pulled out his stent that had been passed through Stensen's duct and taped to his cheek. Nevertheless, he had instantaneous cessation of all salivary leakage down his cheek with no late evidence of sialocele or other complication. At one year, facial muscle function was improved (Fig. 3,with no recurrence of the presenting complaints. He agreed to have a sialogram performed. Narrowing was noted at a site consistent with the anastomosis, but filling of parotid gland radicles was not obstructed (Fig. 6).
CASE REPORTS Case 1 Delayed repair of parotid fistula. A 27-year-old man involved in an altercation suffered a vertical laceration across the mid-portion of his left cheek closed elsewhere (Fig. 3). Inability to elevate his left upper lip was noted (Fig. 4). His major complaint was that for the 2 weeks since injury, copious clear fluid was draining from the wound. This was soaking the diaper that he had to wear around his neck (Fig. 3). Intraoperative wound exploration following the path of the saliva immediately allowed identification of both ends of the divided parotid duct overlying the masseter muscle (Fig. 1). This was repaired over a stent using 9 - 0 nylon sutures and the operating microscope (Fig. 2). No leak was
Case 2 Immediate repair of iatrogenic parotid duct laceration. A 48-year-old woman underwent cosmetic rhyti-
dectomy. During blunt elevation of the deeper superficial musculoaponeurotic system (SMAS) layer anterior to the parotid gland, inadvertent injury to the right parotid duct and a small adjacent branch of the facial nerve was recognized, a known risk of this di~section.'~ Both were repaired using 10-0 nylon sutures with the operating microscope. No unusual facial swelling nor facial paralysis was noted in the immediate postoperative period. No stent was placed in the parotid duct. At one year follow-up, she is content with
Microsurgery of the Parotid Duct
Figure 3. Location of vertical left mid-cheek laceration should arouse a high degree of suspicion of a parotid duct injury. The diaper around his neck was to collect the huge volume of salivary discharge from the cutaneous fistula.
245
c o m e , this is a clue that simultaneous injury to the parotid duct has also occurred. Figure 5. One year later, grimace is markedly improved, and no drip pad is employed.
Figure 4. Paresis of the left upper lip due to injury of the facial nerve branch as shown in Figure 7. Because of theirjuxtaposedanatomical
her facial appearance and had no complaints referable to her untoward parotid duct injury. Because of an iodine allergy, she declined a sialogram. DISCUSSION
The opportunity to repair a parotid duct injury is not a commonplace event, as these two cases represent my entire experience over the past 10 years. In order to preserve parotid gland function, it would seem reasonable from the experience of others to attempt reanastomosis of the divided ends of the duct.’-3,7,8 The means to do this, however, is the point of contention. Classical dictums as to the choice of suture material, the need for stenting of the repair, and the use of magnification need to be ~hallenged.~.’ All types of suture materials have been used to repair the parotid Absorbable sutures may dissolve too soon or may create an inflammatory reaction, as does silk, which on at least one occasion has been incriminated as the cause of a postoperative leak leading to cutaneous fistulization.’ This was in contradistinction to all other repairs by the same surgeon where he had no complications if small-caliber inert nylon sutures were used.2 Others also have used 10-0 nylon microsutures with proven success. loupe magnification may be adequate,’ the operating microscope facilitates the handling of such small sutures as well as providing better visualiza-
Figure 6. Although asymptomatic, the patient in case 7 agreed to a sia/wram. Narrowing is noted corresponding to the site of microanastomoses, but parofid gland radicles freely fill beyond this.
246
Hallock
tion of the mucosal lining of the parotid duct, whose internal diameter can be less than a few millimeters'.'0 (Fig. 2). REFERENCES The role of a stent across any parotid duct anastomosis 1. Tachmes L, Woloszyn T, Marini C, Coons M, Eastlick L, Shaftan G, is less clear. For small blood vessels, this technique is Saltzman EI: Parotid gland and facial nerve trauma: A retrospective review. J Trauma 30:1395-1398, 1990. known to allow better exposure of the intima14and certainly Stevenson JH: Parotid duct transection associated with facial trauma: provided this advantage as documented in Case 1. Stricture 2. Experience with 10 cases. Br J Plast Surg 36231-82, 1983. from subsequent edema is theoretically avoided by a space 3. Barton NW, Miller SH, Graham W P Managing lacerations of the parotid gland, duct and facial nerve. Am F m Physician 12130-134. occupying Yet, stenosis of the parotid duct has oc1976. curred even with an indwelling splint.' Schultz stents total 4. Bornstein LA, Simon BE: Successful primary repair of severed paparotid duct lacerations 5-7 days but removes it immedirotid duct. Plast Reconsrr Surg 6:217-227, 1950. 5 . Schulb RC: Soft tissue injuries of the face, in Smith JW, Aston SJ ately after repair of a partial p ace ration.^ Others stent all (eds): Grubb and Smith's Plastic Surgery. 4th Ed. Boston, Little, repairs anywhere up to 2 week^.'*^*^^'^^'^ In many cases, Brown, 1991, pp 336-337. the stent has been removed during the original anaesthesia 6. Rudolph R: Depth of the facial nerve in face lift dissections. Plast Reconstr Surg 85537-544, 1990. or inadvertently dislodged immediately thereafter with no 7. Kitamura T, Togawa K: Surgery of Stensen's duct. Arch Otolaryngnl untoward sequela.2*11The thick fibrous anatomy of the pa93:189-193, 1971. rotid duct wall inherently reduces the risk of collapse and 8. Halsband ER, Doku HC, Maloney P L Parotid duct laceration: Report of cases. J Oral Surg 28:123-124, 1970. therefore also makes the need for postoperative anastomotic 9. Manson PN: Facial injuries, in McCarthy JG, (ed): Plastic Surgery, support to ensure patency less compel~ing.~ Vol. 2, Philadelphia, WB Saunders, 1990, pp 906-908. No series has been, or may ever be, large enough to 10 Holt GR, Holt JE: Lacerations of the lacrimal apparatus, parotid duct, and facial nerve: Case report. J T r a m 16:414-419, 1976. prospectively provide an answer to all these variables. With the advent of microsurgical equipment and technique, and 11. DeVylder J, Carlo J, Stratigos GT: Early recognition and treatment of the traumatically transected parotid duct: Report of case. J Oral Surg our knowledge of the effects of small inert sutures on heal36:43-44, 1978. ing of the microvasculature, it seems reasonable to extrap- 12. Woodburne R T Essentials of Human Anatomy, 4th Ed. New York, Oxford University Press, 1969, pp 205-207. olate the benefits of this approach for the repair of the 13. Bansberg SF, Krugman ME: Parotid salivary fistula following rhytilacerated parotid duct as well. The use of microsuture with dectomy. Ann Plast Surg 2461-62, 1990. the magnification provided by the operating microscope 14. Cong Z, Nongxuan T, Changfu Z, Yuanwei X, Tongde W: Experimental study on microvascular anastomosis using a dissolvable stent permits a superior anastomosis that may also eliminate the support in the lumen. Microsurgery 12:67-71, 1991. need and inconvenience of postoperative cannulation of the 15. Abramson M: Treatment of parotid duct injuries. hryngoscope 83: parotid duct. 1764-1768, 1973.
