Alternative Approach to Traumatic Stensen’s Duct Injuries Accompanied by Glandular Involvement: Botulinum Toxin Injection to the Gland in Conjunction with Microsurgical Repair of the Duct in an Acute Setting Glandüler Yaralanmanın Eşlik Ettiği Travmatik Stenon Kanalı
Yaralanmalarına Alternatif Yaklaşım: Kanal Kesilerinde Mikrocerrahi Onarıma Ek Olarak Akut Dönemde Beze Botulinum Toksin Enjeksiyonu
Mert Çalış1, Zeynep Öz1, Hakan Uzun1, Burçe Özgen2, Alp Çetin3, Ali Emre Aksu1
1Department of Plastic Reconstructive and Aesthetic Surgery, Hacettepe University School of Medicine, Ankara, Turkey
2Department of Radiology, Hacettepe University School of Medicine, Ankara, Turkey
3Department of Physical Medicine and Rehabilitation, Hacettepe University School of Medicine, Ankara, Turkey
DOI: 10.5152/TurkJPlastSurg.2017.2305
183
www.turkjplastsurg.org
Correspondence Author / Sorumlu Yazar: Ali Emre Aksu E-posta / E-mail: aemreaksu@gmail.com
Received / Geliş Tarihi: 26.09.2017 Accepted / Kabul Tarihi: 03.10.2017 Cite this article as: Çalış M, Öz Z, Uzun H, Özgen B, Çetin A, Aksu AE. Alternative Approach to Traumatic Stensen’s Duct Injuries Accompanied by Glandular Invol- vement: Botulinum Toxin Injection to the Gland in Conjunction with Microsurgical Repair of the Duct in an Acute Setting. Turk J Plast Surg 2017; 25(4): 183-7.
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Abstract
Objective: The aim of this study was to evaluate the long-term re- sults of a simultaneous application of botulinum toxin to the parotid gland in conjunction with the microsurgical repair of the duct in an acute setting and to encourage using botulinum toxin as a first-line option to prevent future complications associated with glandular involvement.
Material and Methods: Three patients who were referred to the Plastic Surgery Clinic by the emergency room of the Hacettepe Uni- versity Hospital after maxillofacial trauma are reviewed in this study.
Exploration of the facial nerve and Stensen’s duct was planned for all patients within the first 72 hours after their injuries. After intraoral catheterization of the Stensen’s duct through the papilla using an epidural catheter, microsurgical end-to-end anastomosis was per- formed. Concurrently, 100 units of botulinum toxin A was injected at standardized eight points to the parotid gland.
Results: Postoperative magnetic resonance (MR) sialography re- vealed patency in all patients at the end of postoperative first year.
The mean postoperative parotid volume of the injured and non-in- jured sides were 19.82±10.55 cm3 and 17.79±10.98 cm3, respective- ly, and the results were found to be comparable. Fibrillation poten- tials in the postoperative electromyography recordings and clinical examination demonstrated nerve regeneration.
Conclusion: Botulinum toxin A appears to be effective in treating duct injuries accompanied by glandular involvement in an acute set- ting, as well as in preventing long-term complications.
Keywords: Botulinum toxin, Stensen’s duct, parotid gland injuries, acute setting
Öz
Amaç: Bu çalışmanın amacı, parotis kanal kesilerinin mikrocerrahi olarak onarımı ile eş zamanlı olarak bez yapısının da yaralandığı ol- gularda akut dönemde botulinum toksin uygulanmasının uzun dö- nem sonuçlarının değerlendirilmesi ve bezin de yaralanmaya dahil olduğu olgularda botulinum toksin uygulamasının birinci basamak tedaviye dahil edilmesini teşvik etmektedir.
Gereç ve Yöntemler: Hacettepe Üniversitesi acil servisi tarafından plastik cerrahi kliniğine maksillofasiyal travma sonrası konsülte edilen üç hasta bu çalışmada değerlendirilmiştir. Tüm hastalarda yaralanmayı takip eden ilk 72 saat içinde fasiyal sinir ve Stenon kanalının eksplorasyonu planlanmıştır. Stenon kanalının papilla yoluyla epidural katater ile intraoral kateterizasyonunu takiben, mikrocerrahi ile uç uca anastamoz gerçekleştirilmiştir. Eş zamanlı olarak, 100 ünite botulinum toksin parotis bezi üzerinde standardi- ze sekiz noktaya uygulanmıştır.
Bulgular: Postoperatif MR sialografi birinci yıl sonunda tüm has- talarda Stenon kanalının patent olduğunu göstermiştir. Ortalama parotis bez volümleri yaralanma olan ve olmayan tarafta sırasıyla 19,82±10,55 cm3 ve 17,79±10,98 cm3 olarak ölçülmüş olup, ista- tistiksel olarak benzer bulunmuştur. Postoperatif elektromyografi ölçümlerinde görülmüş olan fibrilasyon potansiyelleri ve klinik gö- rünüm sinir rejenerasyonu olarak yorumlanmıştır.
Sonuç: Botulinum toksin A, glandüler komponentin eşlik ettiği ka- nal yaralanmalarında hem akut dönemde tedavide hem de uzun dönemde komplikasyonların önlenmesinde etkili olarak gözük- mektedir.
Anahtar Sözcükler: Botulinum toksin, Stenon kanalı, parotis bez yaralanmaları, akut dönem
INTRODUCTION
Besides causing cosmetic deformities, traumatic facial lacer- ations may also lead to the injury of deeper anatomic struc- tures, such as Stensen’s duct, parotid gland, and facial nerve and artery. The leading causes of parotid duct injuries are lacerations by sharp penetrating objects, such as razor and automobile glass. Etiologically these are followed by gun- shot wounds and iatrogenic causes secondary to surgical procedures.1 There is a high tendency to overlook this diag- nosis and focus on multiple associated traumatic injuries, such as facial nerve paralysis, since the incidence injuries to the parotid gland and its duct is relatively rare. Missing the parotid insult may lead to otherwise avoidable compli- cations, such as facial deformities, scarring, sialoceles, cuta- neous fistulae, salivary gland cysts, and gustatory sweating (Frey’s syndrome).2 There are reports in the literature appre- ciating the difficulty of diagnosis in an acute setting.3 To pre- vent long-term complications and to restore the functions of the parotid gland, it is important to immediately diagnose and treat duct injuries.
The aim of this study was to evaluate the long-term results of a simultaneous application of botulinum toxin to the parotid gland in conjunction with the microsurgical repair of the duct in an acute setting and to encourage using botulinum toxin as a first-line option to prevent future complications associat- ed with glandular involvement.
MATERIAL AND METHODS Patients
Our clinical experience with tree patients referred to our Plas- tic Surgery Clinic by the emergency room of the Hacettepe University Hospital after a maxillofacial trauma is reviewed in this study. All patients presented with severe facial lacerations extensively involving the superficial musculoaponeurotic sys- tem. Two of the patients had motor vehicle accidents, and the third had been attacked with a sharp penetrating object.
The demographic and perioperative variables of the patients, such as age, sex, involved structures, surgical approach, post- operative complications, results of postoperative electromy- ography (EMG) evaluation, and bilateral volumetric analysis of parotid gland were recorded.
Surgical Procedure
Exploration of the facial nerve and Stensen’s duct was planned for all patients within the first 72 hours after the injury. Upon exploration, proximal and distal ends of the Stensen’s duct and the branches of the facial nerve affected by the injury were identified. Following intraoral catheterization of the Stensen’s duct through the papilla using an epidural catheter, microsurgical end-to-end anastomosis using a 9.0 suture was performed. Simultaneous repair of the nerve endings of the involved branches of the facial nerve was co-apted using 9.0 suture with an epineural technique (Figures 1A-1C). Concur- rently, 100 units of botulinum toxin A (Botox; Allergan, USA) was injected at standardized 8 points to the parotid gland (Figure 2). The epidural catheter was left in place for 10 days to act as a stent for the anastomosis.
Electromyography Evaluation of the Facial Nerve
Electromyography evaluation was performed to assess the regeneration of the involved facial nerve branches at the end of the postoperative first year. Bilateral recordings of the am- plitude of compound motor action potential and latencies from the frontalis, zygomaticus, nasalis, and orbicularis oris muscles of both the injured and the non-injured sides, with respect to the involved nerve branch, were recorded.
Volumetric Analysis of the Parotid Gland
Postoperative parotid MR sialography examinations of the pa- tients one year after the injury were analyzed retrospectively using a picture-archiving computer system. Examinations of all three patients were performed using a 1.5 T MR imaging (MRI) unit (Symphony TIM, Siemens, Erlangen, Germany).
Coronal fat-saturated T2-weighted images for Case 1, coronal T2-weighted images for Case 2, and transverse fat-saturated T2-weighted images for Case 3 were selected. All images were transferred to a workstation (LEONARDO, Siemens Medical Solutions, Erlangen, Germany). The surface area of both in- jured and non-injured parotid glands were calculated in each image and the total volumes of the parotid glands were calcu- lated by multiplying the sum by section thickness.
Statistical Methods
Statistical Package for Social Sciences (SPSS) for Windows 21.0 (SPSS Inc.; Armonk, NY, USA) was used for statistical analysis.
The normal distribution pattern of the quantitative data was
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Figure 1.a-c. (a) Intraoral catheterization of the Stensen’s duct through the papilla with an epidural catheter. (b) Upon exploration, proximal and distal ends of the Stensen’s duct are identified and catheterized. (c) Intraoperative appearance of the parotid duct (P) and zygomatic branch (Z) of the facial nerve following microsurgical repair using a 9.0 suture with an epineural technique
evaluated using the Shapiro-Wilk test. Descriptive statistical values were expressed as mean±standard deviation (Std) and median (maximum-minimum). Given the small sample size, parametric independent Samples T tests, as well as non- parametric Mann-Whitney U tests were used to compare the
postoperative parotid volumes of the injured and non-injured sides. Moreover, simulation was performed to extrapolate the results to wider populations using the Bootstrap method and these results were also documented. P values <0.05 were con- sidered statistically significant.
RESULTS
Postoperative MR sialography revealed patency in all patients at the end of the postoperative first year (Figure 3). Results of the volumetric analysis are summarized in Table 1. The mean postoperative parotid volume of the injured and non-injured sides was 19.82±10.55 cm3 and 17.79±10.98 cm3, respectively, and the results were found to be comparable with both para- metric and nonparametric statistical evaluation (p=0.828 and p=0.700, respectively). Simulation of these results to wider populations were also not significantly different (p=0.765 and p=0.705, respectively).
Electromyography recordings related to the involved branch- es of the facial nerve are summarized in Table 2. Fibrillation potentials in postoperative recordings and clinical examina- tion demonstrated nerve regeneration (Video).
DISCUSSION
Although the incidence of facial trauma is relatively common, parotid duct injuries represent merely a small portion of the inju- ries. This is due to the rarity of the duct lacerations as well as undi- agnosed cases.4 Overlooking the injury to the parotid gland and duct may lead to otherwise avoidable late-term complications, such as facial disfigurement, sialoceles, fistulae, and gustatory sweating.1 Another important point concerning parotid injuries is the close anatomic relationship of the buccal branch of the fa- cial nerve, which may also be affected from the insult.5,6
There are three basic approaches to manage Stensen’s Duct lacerations in an acute setting: suppression of the gland and conservative follow-up, diversion of the duct to create an in- traoral controlled fistula, and microsurgical repair of the duct.
The conservative treatment modalities are pressure dress- ings, restriction of oral intake for several weeks, serial aspira- tions, and administration of antibiotics and anti-sialagogues.
In cases of severe avulsion injuries, for diversion and creating an intraoral fistula, the proximal portion of the duct may be brought to the oral cavity through the buccinator muscle.1
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Figure 2. One-hundred Units of botulinum toxin A was injected intra- operatively at standardized 8 points to the parotid gland
Figure 3. Postoperative MRI sialography demonstrates patency of the microsurgically repaired Stensen’s duct (yellow arrow) at the end of postoperative first year (MRI: magnetic resonans imaging)
Tablo I. Total volume of both injured and non-injured parotid glands were compared using parotid MR sialography images at the postoper- ative first year
Injured Non-injured p p (Bootstrap)
17.79±10.98* 19.82±10.55* 0.828 0.765****
14.2(30.12-9.05)** 16.7(31.58–11.19)** 0.700*** 0.705****
MRI: magnetic resonance imaging Independent T Test -Mann-Whitney U test Mean±standard deviation*
Median (maximum-minimum)**
p value using Mann-Whitney U test***
p value using the Bootstrap method****
Among the three treatment options, if possible, it is ideal to perform microsurgical anastomosis by catheterizing the two- ends of the duct using a silastic tube1. Alternatively, Chuda- kov and Ludchik7 proposed the use of interpositional vein to repair severely damaged parotid duct injuries. Sujeeth et al.8 presented a case report of a parotid duct injury treated with insertion of an epidural catheter.
Botulinum toxin, by inhibiting the release of acetylcholine from the presynaptic terminal of the neuromuscular junction, leads to selective chemical denervation. Since the function of the salivary glands is regulated by cholinergic autonomic nerves, injection of botulinum toxin not only affects skeletal muscles but also the cholinergic fibers of the parotid gland controlling salivary flow. Thus, botulinum toxin A temporar- ily inhibits the secretion function of the salivary glands and is therefore known to be an efficient anti-secretagogue to be used in clinical practice.9
Botulinum toxin injection is preserved for isolated parenchy- mal injuries in which the duct was not repaired or to decrease the secretion in the treatment of the late complications, such as the formation of sialoceles and fistulae.10,11 In literature, the usage of anti-sialagogues in the presence of a ductal injury has been controversial. Parekh et al. proposed that anti-sial- agogue strategies have an accelerating effect on the healing process of parenchymal injuries, while reporting high failure rates in the presence of ductal injury.12
In our clinical experience, we have seen that a large area is affected in facial lacerations and that parotid parenchyma injury accompanied the Stensen’s duct injury. Therefore, al- though not preferred for ductal injuries in an acute setting, we applied 100 units of botulinum toxin A at 8 points to the parotid gland in addition to the microsurgical repair of the duct. Our aim was to decrease the secretion in the remain- ing parenchyma and to prevent the pseudocapsule forma- tion and inflammation that may lead to chronic complica- tions. Follow-up MRI scanning at the end of the first year revealed no significant volumetric differences between the non-injured contralateral parotid gland and the botulinum toxin A-applied injured one. This result demonstrates that the anti-secretagogue effect of the botulinum toxin on the
gland is temporary and that it does not cause atrophy. Addi- tionally, it is important to emphasize the close relationship of the buccal branch of the facial nerve and parotid duct as all three cases of duct injury are accompanied by facial nerve laceration.
CONCLUSION
In conclusion, botulinum toxin A appears to be effective in treating duct injuries accompanied by glandular involvement in an acute setting, as well as in preventing long-term com- plications.
Etik Komite Onayı: Çalışmaya katılan hasta sayısının sınırlılığından dolayı bu çalışma için etik komite onayı gerekmemektir.
Hasta Onamı: Hasta onamı bu çalışmaya katılan hastalardan alın- mıştır.
Hakem Değerlendirmesi: Dış bağımsız.
Yazar Katkıları: Fikir - A.E.A., M.Ç.; Tasarım - M.Ç., Z.Ö.; Denetleme - A.E.A.; Kaynaklar - M.Ç., H.U.; Malzemeler - M.Ç., Z.Ö., H.U.; Veri To- planması ve/veya işlemesi - M.Ç., Z.Ö., B.Ö., A.Ç.; Analiz ve/veya Yo- rum - B.Ö., A.Ç., M.Ç.; Literatür taraması - M.Ç., Z.Ö.; Yazıyı Yazan - M.Ç.;
Eleştirel İnceleme - A.E.A.
Çıkar Çatışması: Yazarlar çıkar çatışması bildirmemişlerdir.
Finansal Destek: Yazarlar bu çalışmada finansal destek alınmadığını bildirmişlerdir.
Ethics Committee Approval: Ethic committee approval is not re- quired for this study due to the limited amount of patients involved in the study.
Informed Consent: Informed consent was obtained from the pa- tients for the publication of this study.
Peer-review: Externally peer-reviewed.
Author contributions: Concept – A.E.A., M.Ç.; Design – M.Ç., Z.Ö.; Su- pervision – A.E.A., Resource – M.Ç., H.U.; Materials – M.Ç., Z.Ö., H.U.;
Data Collection and/or Processing – M.Ç., Z.Ö., B.Ö., A.Ç.; Analysis and/
or Interpretation – B.Ö., A.Ç., M.Ç.; Literature Search – M.Ç., Z.Ö.; Writ- ing Manuscript – M.Ç.; Critical Reviews – A.E.A.
186
Tablo II. Total volume of both injured and non-injured parotid glands were compared using parotid MR sialography images at the postoper- ative first year
Injured side Non-injured side
Patient Muscle Amplitude (mV) Latency (ms) Amplitude (mV) Latency (ms)
1 Orbicularis 0.6 6.4 1.7 4.4
Nasalis 0.2 3.3 2.6 2.5
2 Orbicularis 1.3 3.3 3.6 3.0
Zygomaticus - - 0.6 5.0
3 Frontalis 1.6 2.9 2.5 3.0
Nasalis 1.3 15.1 1.8 2.8
EMG: electromyography; mV:millivolts; ms: miliseconds
Conflict of Interest: No conflicts of interest were declared by the au- thors.
Financial Disclosure: The authors declared that this study has re- ceived no financial support.
REFERENCES
1. Steinberg MJ, Herrera AF. Management of parotid duct injuries.
Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2005; 99(2):
136-41. [CrossRef]
2. Gordin EA, Daniero JJ, Krein H, Boon MS. Parotid gland trauma.
Facial Plast Surg 2010; 26(6): 504-10. [CrossRef]
3. DeVylder J, Carlo J, Stratigos GT. Early recognition and treatment of the traumatically transected parotid duct: report of case. J Oral Surg 1978; 36(1): 43-4.
4. Etoz A, Tuncel U, Ozcan M. Parotid duct repair by use of an em- bolectomy catheter with a microvascular clamp. Plast Reconstr Surg 2006; 117(1): 330-1. [CrossRef]
5. Pogrel MA, Schmidt B, Ammar A. The relationship of the buccal branch of the facial nerve to the parotid duct. J Oral Maxillofac Surg 1996; 54(1): 71-3. [CrossRef]
6. Tachmes L, Woloszyn T, Marini C, Coons M, Eastlick L, Shaftan G, et al. Parotid gland and facial nerve trauma: a retrospective re- view. J Trauma 1990; 30(11): 1395-8. [CrossRef]
7. Chudakov O, Ludchik T. Microsurgical repair of Stensen’s &
Wharton’s ducts with autogenous venous grafts. An experimen- tal study on dogs. Int J Oral Maxillofac Surg 1999; 28(1): 70-3.
[CrossRef]
8. Sujeeth S, Dindawar S. Parotid duct repair using an epidural catheter. Int J Oral Maxillofac Surg 2011; 40(7): 747-8. [CrossRef]
9. Ellies M, Gottstein U, Rohrbach-Volland S, Arglebe C, Laskawi R.
Reduction of salivary flow with botulinum toxin: extended re- port on 33 patients with drooling, salivary fistulas, and sialade- nitis. Laryngoscope 2004; 114(10): 1856-60. [CrossRef]
10. Lewis G, Knottenbelt JD. Parotid duct injury: is immediate surgi- cal repair necessary? Injury 1991; 22(5): 407-9. [CrossRef]
11. Arnaud S, Batifol D, Goudot P, Yachouh J. Non-surgical manage- ment of parotid gland and duct injuries: interest of botulinum toxin. Ann Chir Plast Esthet 2008; 53(1): 36-40. [CrossRef]
12. Parekh D, Glezerson G, Stewart M, Esser J, Lawson HH. Post-trau- matic parotid fistulae and sialoceles. A prospective study of conservative management in 51 cases. Ann Surg 1989; 209(1):
105-11. [CrossRef]
