- Email: [email protected]
Combined External Lithotripsy and Endoscopic Techniques for Advanced Sialolithiasis Cases
J Oral Maxillofac Surg 68:347-353, 2010
Combined External Lithotripsy and Endoscopic Techniques for Advanced Sialolithiasis Cases Oded Nahlieli, DMD,* Rachel Shacham, DMD,† and Ami Zaguri, DMD‡ Purpose: To assess a combined external lithotripsy-sialoendoscopy method developed for advanced
salivary gland sialolithiasis. Materials and Methods: A total of 94 patients (43 males and 51 females) underwent these treatment
methods. Of these 94 patients, 60 had pathologic features in the submandibular gland and 34 in the parotid gland. A miniature external lithotripter was used, combined with multifunctional sialoendoscopes and endoscopic-assisted techniques, to achieve effective removal/elimination of the stones in these difficult cases. Results: Total elimination of the stone using lithotripsy alone was achieved in 32% of the cases; in 29%, intraductal endoscopic assistance was needed. In the remaining 39%, the removal of a stone was achieved with the help of an endoscopy-assisted extraductal approach (37 cases). At 6 months of follow-up, all patients who had undergone lithotripsy or lithotripsy plus intraductal endoscopy had an absence of symptoms. Of the 37 patients who had undergone an endoscopy-assisted extraductal approach, 35 (95%) remained asymptomatic. Conclusions: Lithotripsy plus intraductal or extraductal endoscopic treatment of sialolithiasis is a highly effective surgical method of eliminating/removing salivary stones, especially those attached to the surrounding tissue and in the secondary ducts. This method helps to avoid resection of the salivary glands and represents an additional development of minimal invasive surgical techniques. © 2010 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 68:347-353, 2010 population.1 Other common salivary gland pathologic features (other than tumors) include sialadenitis, strictures, and kinks. The diagnosis and treatment of this problem have traditionally been hampered by the limitations of the standard imaging techniques. Satisfactory management depends on the surgeon’s ability to reach a precise anatomic diagnosis and, in the case of the sialoliths, to locate the obstruction most accurately. Traditionally, sialoliths in the submandibular or parotid ducts and glands were divided into 2 groups:
Sialoendoscopy is a novel technique that has added a significant new dimension to the surgeon’s armamentarium for the diagnosis and management of inflammatory salivary disease. Obstructive sialadenitis, with or without sialolithiasis, represents the most common inflammatory disorder of the major salivary glands. Sialolithiasis is one of the major causes of sialadenitis. Calculi in the salivary glands can be found in 1.2% of the general
*Professor and Chairman, Department of Oral and Maxillofacial Surgery, Barzilai Medical, Center, Ashkelon, Israel, Affiliated With Ben Gurion University of the Negev Faculty of Medicine, Beer Sheva, Israel; and Consultant, Sialotechnology, Ashkelon, Israel. †Attending Surgeon, Department of Oral and Maxillofacial Surgery, Barzilai Medical Center, Ashkelon, Israel. ‡Attending Surgeon, Department of Oral and Maxillofacial Surgery, Barzilai Medical Center, Ashkelon, Israel. Address correspondence and reprint requests to Dr Nahlieli: Department of Oral and Maxillofacial Surgery, Barzilai Medical Center, Ashkelon 78306 Israel; e-mail: [email protected]
1. Stones that could be removed using an intraoral sialolithotomy approach, because they were usually located in the anterior part of the duct 2. Stones that could not be removed using the intraoral approach, such that extirpation of the entire gland, or sialoadenectomy, is necessary Another pathologic finding requiring gland removal was recurrent sialadenitis. The morbidity that occurs after traditional approaches for parotid and submandibular sialoadenectomy includes a number of complications. Neurologic
© 2010 American Association of Oral and Maxillofacial Surgeons
0278-2391/10/6802-0019$36.00/0 doi:10.1016/j.joms.2009.09.041
347
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FIGURE 1. Intraoperative view showing identification of parotid stone with help of a sialoendoscope and adaptation of a lithotripter applicator. Nahlieli, Shacham, and Zaguri. Combined External Lithotripsy and Endoscopy for Sialolithiasis. J Oral Maxillofac Surg 2010.
damage after superficial parotidectomy is a primary concern, because 16% to 38% of patients will develop temporary nerve weakness, and 9% will have permanent damage.2,3 During submandibular gland removal, a 7% risk of permanent marginal mandibular nerve damage and a 3% risk of damage to the lingual nerve exist.4 Frey’s syndrome, facial scarring, greater auricular nerve numbness, sialoceles, and salivary fistulas also contribute to the morbidity of the traditional procedure.3 During the past decade, rapid developments in technology, especially optical miniaturization, lithotripsy equipment, and micro-instruments, and the influence from other surgical fields, have directed us to develop new methods of treatment, including noninvasive, minimally invasive, and less-invasive procedures. Although we have been able to remove most salivary stones with the available techniques, we decided to combine these methods for advanced cases. We hypothesized that with this innovation, we would be able to solve more complicated cases without major surgery and perform the cases more easily and with a better success rate, with the return of the gland to normal function. In the present report, we assessed a combined lithotripsy-sialoendoscopy method developed for advanced salivary gland sialolithiasis cases using data from a prospective study.
present study for combined treatment. Of the 94 patients, 60 had pathologic features in the submandibular gland and 34 in the parotid gland. In contrast to small stones in the main salivary duct, the 5-mm stones located in the secondary ducts or intraparenchymally were considered to not be straightforward cases and, therefore, were included in the present study. The inclusion criteria were as follows. For the submandibular gland cases, patients were included if they had a small (⬍5 mm) stone in secondary ducts or intraparenchymal stone (n ⫽ 14 patients), a small (⬍5 mm) fixed stone in the main duct in the hilus region (n ⫽ 20 patients), or a medium to large (⬎5 mm) hilar or intraglandular stone attached to the surrounding tissue that was immobile or difficult to palpate (n ⫽ 26 patients). For the parotid gland cases, patients were included if they had a small (⬍5 mm) stone in the main or secondary duct proximal from the middle part of the duct (n ⫽ 8 patients), a small (⬍5 mm) stone in the secondary ducts or an intraparenchymal stone (n ⫽ 11 patients), or a medium to large (⬎5 mm) hilar or intraglandular stone attached to the surrounding tissue that was immobile or difficult to palpate (n ⫽ 15 patients). The exclusion criteria were similar for both locations and included small (⬍5 mm) mobile stones in the main duct and medium to large (⬎5 mm) hilar mobile palpable stones. The present prospective study was conducted according to the medical ethical regulations in Israel. All the combined parts of the treatment (lithotripsy, endoscopy, and endoscopic-assisted techniques) are well-known and accepted methods for sialolithiasis in Israel and Europe. TECHNICAL DATA
A miniature external lithotripter (extracorporeal shock wave lithotripsy; Sialotechnology, Ashkelon, Israel) was used in the present study. The technical details were as follows: electrohydraulic energy ⫺10 to 24 kV, miniature generator and applicator, focal
Materials and Methods PATIENTS
In the past 2 years, 94 patients (43 males and 51 females), aged 6 to 87 years were enrolled in the
FIGURE 2. View of 1.1-mm modular saliva scope with integrated grasping forceps. Nahlieli, Shacham, and Zaguri. Combined External Lithotripsy and Endoscopy for Sialolithiasis. J Oral Maxillofac Surg 2010.
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FIGURE 3. A, Computed tomography scan of a 42-yearold man after failed endoscopic attempt to extract a sialolith identified in the right parotid gland showing a stone in the hilar region (arrow). B, Endoscopic view of a stone located near the hilum of the parotid gland in the secondary duct. C, Computed tomography scan of the same patient 1 month after the second session showing anterior movement of a stone to middle part of the Stensen’s duct (arrow). D, Intraoperative view of the patient during stone removal. Yellow arrow indicates original location of the stone, transillumination marked with yellow circle indicates new location of the stone near the Stensen’s duct orifice. E, Removal of the stone located near the Stensen’s duct orifice. Nahlieli, Shacham, and Zaguri. Combined External Lithotripsy and Endoscopy for Sialolithiasis. J Oral Maxillofac Surg 2010.
point depth ⫺15 ⫻ 15 ⫻ 25, large focus zone (focus at 50%) ⫺35 mm, and penetration depth ⫺120 mm. The diameter of the generator was not larger than a computer box, and the working head was reduced to
fit the dimensions of the head and neck region. The technique delivered 1,000 to 1,500 shock waves per session. An ultrasound transducer could be attached to the applicator head (Fig 1).
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The endoscopic armamentarium included the modular salivascope system (PolyDiagnost GmbH, Pfaffenhofen, Germany), containing a telescope with 6,000pixel illumination fibers, a focal length of 2 to 15 mm, and a 70° field of view, was used. The diameter of the telescope was 0.5 mm (Fig 2). All the sleeves (0.9, 1.1, 1.6, and 2.0 mm) are disposable, and the optical part (the telescope) can be autoclaved. We used the PolyDiagnost Salivascope Flex (type PD ZS 2001, 1.1-mm, PolyDiagnost GmbH) all-in-one type endoscope with 6,000 pixels and 2 channels for surgical instruments and for irrigation. The instruments used for stone extraction with the endoscopic system included were stone grasping baskets miniforceps (PolyDiagnost GmbH) and high-pressure balloons (Sialotechnology). Finally, we also used the Sialoview MDI, 1.1-mm (Millennium, Islandia, NY), all-in-one type endoscope, with 6,000 pixels and 2 channels for surgical instruments and irrigation. The instruments used for stone extraction with the endoscopic system included stonegrasping baskets mini-forceps (PolyDiagnost GmbH), and high-pressure balloons (Sialotechnology). SURGICAL APPROACH
Ultrasonography and endoscopy were used to assist in locating the stone. The endoscope was then used to irrigate and inflate the salivary gland with isotonic saline and 2% lidocaine. External lithotripsy was then applied with low-energy levels up to 130 atm at 1,000 to 1,500 shock waves per session. Three sessions of extracorporeal shock wave treatment per patient were administered with a 1-month interval between each session. Because of the low energy of the shock waves, the procedure was not painful and did not require any anesthesia. After the results of lithotripsy, as assessed by plain radiographic sialography, ultrasonography, or computed tomography, either an intraductal endoscopic approach was used (pure endoscopic procedure) or an endoscopy-assisted extraductal approach was chosen (endoscopy-assisted technique). Thus, 3 types of treatment were performed: lithotripsy, lithotripsy plus intraductal endoscopy (pure endoscopy), or lithotripsy plus an endoscopic-assisted extraductal approach5-8 (a stretching procedure for the submandibular stones or an extraoral approach for the parotid stones). The second and third methods were used for patients in whom a salivary stone could not be eliminated using lithotripsy alone (Figs 3A-3E, 4A-4B, 5A-5D). The follow-up examinations were performed from 6 to 24 months postoperatively.
FIGURE 4. A, Panoramic view of a 40-year-old man with a deep left submandibular stone. He had experienced multiple episodes of swelling in the 2 years before his referral. B, Top, Radiograph showing original deep location of the stone (circle) posterior to the hilar region. B, Bottom, Radiograph showing stone location (circle) after 3 lithotripsy sessions. Note anterior movement of the stone. Nahlieli, Shacham, and Zaguri. Combined External Lithotripsy and Endoscopy for Sialolithiasis. J Oral Maxillofac Surg 2010.
Results Total elimination of the stone by lithotripsy alone was achieved in 30 patients (32%). In 27 patients, (29%), intraductal endoscopic assistance was needed. In 37 patients (39%), stone removal was achieved using the endoscopy-assisted extraductal approach. At 6 months of follow-up, all patients who had undergone lithotripsy or lithotripsy plus an intraductal endoscopic approach were symptom free. In the 37 patients in whom the endoscopy-assisted extraductal approach was used, 35 (95%) remained asymptomatic at 6 months postoperatively. Table 1 lists the results of treatment according to stone location and property. An unexpected positive side effect was detected after the combined treatment. Although it is not usually expected for the gland to return to normal func-
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FIGURE 5. A, Occlusal radiograph of a 32-year-old woman after failed attempt to remove a left submandibular stone showing a 5-mm stone inside the gland. Clinical evaluation revealed enlargement of the left submandibular gland with purulent secretion from the Wharton’s duct orifice. B, Occlusal radiograph after first lithotripsy session showing separation of the stone into 2 pieces. C, Occlusal radiograph after the third lithotripsy session showing 2 parts of the stone had moved anteriorly, one part to the anterior and one to the middle part of the Wharton’s duct. D, Endoscopic removal of the stone from the middle part of the Wharton’s duct. Nahlieli, Shacham, and Zaguri. Combined External Lithotripsy and Endoscopy for Sialolithiasis. J Oral Maxillofac Surg 2010.
tion in patients with long-standing, large-diameter stones, clinical observation showed a return of such glands to normal function. The effect was observed in 16 glands that had had large-diameter stones ⬎15 mm. This effect was detected during the 6 months of follow-up.
Discussion Until recently, the low success rate and very expensive equipment needed were the main obstacles pre-
venting surgeons from the use of the technique we have described. The rapid development in equipment miniaturization, the reduction in equipment costs, and the combination with other minimally invasive techniques have given this lithotripsy technique a place in our armamentarium for the treatment of sialolithiasis. The lithotripter we used generates enough substance to produce the cavitation effect. The success rate with this new lithotripter for the complete removal of stones was 32% in our study. Endoscopic removal
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Table 1. TREATMENT RESULTS STRATIFIED BY LOCATION, SIZE, AND SURGICAL METHOD
Treatment Location
Size
Submandibular Small (n ⫽ 60) Small, fixed Medium/large Parotid Small* (n ⫽ 34) Small† Medium/large‡
Lithotripsy Alone
IEA
EEA
Total
5 4 0 7 5 2
4 6 0 1 5 3
5 10 26 0 1 10
14 20 26 8 11 15
Abbreviations: IEA, intraductal endoscopic approach; EEA, endoscopy-assisted extraductal approach. *Small, ⬍5-mm stone in main or secondary duct proximal from middle part of duct. †Small, ⬍5-mm stone in secondary ducts or intraparenchymal. ‡Medium/large, ⬎5-mm hilar or intraglandular stone. Nahlieli, Shacham, and Zaguri. Combined External Lithotripsy and Endoscopy for Sialolithiasis. J Oral Maxillofac Surg 2010.
of the stones after the lithotripsy sessions was easier and less complicated. The shock waves disconnect the stone from the ductal wall and reduce the stone volume. The disconnection of the stone from the surrounding ductal tissue seems to be the major positive effect of the procedure. We believe that this combined lithotripsy-endoscopy approach could help to overcome the varying sizes, locations, and most of the obstructive conditions, because it involves multiple techniques and technologies (ie, pure endoscopy, endoscopic assistance, and external lithotripsy) that can be combined
A
in the treatment of a single patient. The implementation of these 3 methods relies on the advantages of each method and could lead to effective treatment of most of the obstructive and inflammatory conditions of the salivary glands. We decided to change the treatment philosophy of the lithotripsy procedure and to use it not as a solo technique but as an adjuvant technique. In the past, it was difficult to make endoscopy and endoscopy-assisted techniques easier and to achieve good results in advanced cases. With this insight, we adapted the miniature lithotripter and used low-energy levels to detach the stone from the tissue without breaking it into fragments. Disconnecting the outer cortex of the stone during or after lithotripsy and the positive effect on the formation of scar tissue has provided the possibility for saliva leakage to the oral cavity, bypassing the affected stone. Regaining normal gland function after lithotripsy in patients with medium to large stones appears to be a welcome addition to positive results of treatment. Additional research might be needed to evaluate this phenomenon; however, some speculations can be made. One could speculate that revascularization angiogenesis might occur in the affected salivary gland, similar to the effect of cardiac shock wave therapy. This might have been a suitable explanation, assuming that we used the same energy levels as were used for the cardiac shock wave research and treatment. Extracorporeal shock wave therapy has generated great interest in cardiology since the first report of enhanced neovascularization with shock wave application at the tendon– bone junction in a dog model.9
B B
A
Saliva leakage
S
Detachment
S Revascularization
Shock waves
FIGURE 6. A, Scheme of submandibular gland stone (S) during external lithotripsy. B, Scheme of same gland after external lithotripsy demonstrating 3 effects: detachment of stone, saliva leakage, and revascularization. Nahlieli, Shacham, and Zaguri. Combined External Lithotripsy and Endoscopy for Sialolithiasis. J Oral Maxillofac Surg 2010.
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It was then found that in patients with chronic refractory angina, extracorporeal shock wave therapy was safe and well tolerated. It improved symptoms, exercise capacity, and myocardial perfusion.10 Some evidence was shown in favor of the formation of new capillary networks.11 If this were also the case for salivary glands, the newly proposed treatment might add significantly to our therapeutic capacity in cases of sialolithiasis (Fig 6). Extracorporeal shock wave lithotripsy is an old technique with the main advantage of being noninvasive. The first report on the use of shock waves to fragment sialoliths was by Marmary12 in 1986. The problem at that time appeared to result from the large lithotripsy machine that was available, which had a very broad focus and caused the removal of dental fillings and periosteal irritation. The development of smaller machines with a more finely focused beam of waves led to additional improvement in the method, with a success rate of 50% to 60% for stone removal and up to 100% for symptom alleviation.13,14 It has not been previously used as an adjuvant technique with low levels of energy for the treatment of salivary gland diseases. Our innovation has demonstrated that it can be used in this field with significant success. The lithotripsy plus intraductal or extraductal endoscopic treatment of sialolithiasis is a highly effective surgical method for eliminating or removing salivary stones, especially deep and advanced sialolithiasis cases. This method can help to avoid resection of the salivary glands and represents an additional development in the minimally invasive surgical technique.
References 1. Rauch S, Gorlin RJ: Diseases of the salivary glands, in Gorlin RJ, Goldman HM (eds): Oral Pathology. St Louis, Mosby, 1970, pp 962-1070 2. Mra Z, Komisar A, Blaugrund SM: Functional facial nerve weakness after surgery for benign parotid tumours: A multivariate statistical analysis. Head Neck 15:147, 1993 3. Owen ER, Banerjee AK, Kissin M, et al: Complications of parotid surgery: The need for selectivity. Br J Surg 76:1034, 1989 4. Milton SM, Thomas BM, Bickerton RC: Morbidity study of submandibular gland excision. Ann R Coll Surg Engl 68:148, 1986 5. Nahlieli O, Shacham R, Zagury A, et al: The ductal stretching technique—Endoscopic assisted technique for submandibular stones. Laryngoscope 117:1031, 2007 6. Marchal F: A combined endoscopic and external approach for extraction of large stones with preservation of parotid and submandibular glands. Laryngoscope 117:373, 2007 7. Nahlieli O, London D, Zagury A, et al: Combined approach to impacted parotid stones. J Oral Maxillofac Surg 60:1418, 2002 8. McGurk M, MacBean AD, Fan KF, et al: Endoscopically assisted operative retrieval of parotid stones. Br J Oral Maxillofac Surg 44:157, 2006 9. Caspari GH, Erbel R: Revascularization with extracorporeal shock wave therapy: First clinical results. Circulation 100:84, 1999 (suppl 18) 10. Gutersohn A, Caspari G, Marlinghaus E: Autoangiogenesis induced by cardiac shock wave therapy (CSWT) increases myocardial perfusion in endstage CAD patients. Ch Z Kardiologiia 93:98, 2004 (suppl 3) 11. Fukumoto Y, Ito A, Uwatoku T, et al: Extracorporeal cardiac shock wave therapy ameliorates myocardial ischemia in patients with severe coronary artery disease. Coron Artery Dis 17:63, 2006 12. Marmary Y: A novel and non-invasive method for the removal of salivary gland stones. Int J Oral Maxillofac Surg 15:585, 1986 13. Iro H, Benzel W, Zenk J, et al: Minimally invasive treatment of sialolithiasis using extracorporeal shock waves. HNO 41:311, 1993 14. Zenk J, Bozzato A, Winter M, et al: Extracorporeal shock wave lithotripsy of submandibular stones: Evaluation after 10 years. Ann Otol Rhinol Laryngol 113:378, 2004
Combined External Lithotripsy and Endoscopic Techniques for Advanced Sialolithiasis Cases Oded Nahlieli, DMD,* Rachel Shacham, DMD,† and Ami Zaguri, DMD‡ Purpose: To assess a combined external lithotripsy-sialoendoscopy method developed for advanced
salivary gland sialolithiasis. Materials and Methods: A total of 94 patients (43 males and 51 females) underwent these treatment
methods. Of these 94 patients, 60 had pathologic features in the submandibular gland and 34 in the parotid gland. A miniature external lithotripter was used, combined with multifunctional sialoendoscopes and endoscopic-assisted techniques, to achieve effective removal/elimination of the stones in these difficult cases. Results: Total elimination of the stone using lithotripsy alone was achieved in 32% of the cases; in 29%, intraductal endoscopic assistance was needed. In the remaining 39%, the removal of a stone was achieved with the help of an endoscopy-assisted extraductal approach (37 cases). At 6 months of follow-up, all patients who had undergone lithotripsy or lithotripsy plus intraductal endoscopy had an absence of symptoms. Of the 37 patients who had undergone an endoscopy-assisted extraductal approach, 35 (95%) remained asymptomatic. Conclusions: Lithotripsy plus intraductal or extraductal endoscopic treatment of sialolithiasis is a highly effective surgical method of eliminating/removing salivary stones, especially those attached to the surrounding tissue and in the secondary ducts. This method helps to avoid resection of the salivary glands and represents an additional development of minimal invasive surgical techniques. © 2010 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 68:347-353, 2010 population.1 Other common salivary gland pathologic features (other than tumors) include sialadenitis, strictures, and kinks. The diagnosis and treatment of this problem have traditionally been hampered by the limitations of the standard imaging techniques. Satisfactory management depends on the surgeon’s ability to reach a precise anatomic diagnosis and, in the case of the sialoliths, to locate the obstruction most accurately. Traditionally, sialoliths in the submandibular or parotid ducts and glands were divided into 2 groups:
Sialoendoscopy is a novel technique that has added a significant new dimension to the surgeon’s armamentarium for the diagnosis and management of inflammatory salivary disease. Obstructive sialadenitis, with or without sialolithiasis, represents the most common inflammatory disorder of the major salivary glands. Sialolithiasis is one of the major causes of sialadenitis. Calculi in the salivary glands can be found in 1.2% of the general
*Professor and Chairman, Department of Oral and Maxillofacial Surgery, Barzilai Medical, Center, Ashkelon, Israel, Affiliated With Ben Gurion University of the Negev Faculty of Medicine, Beer Sheva, Israel; and Consultant, Sialotechnology, Ashkelon, Israel. †Attending Surgeon, Department of Oral and Maxillofacial Surgery, Barzilai Medical Center, Ashkelon, Israel. ‡Attending Surgeon, Department of Oral and Maxillofacial Surgery, Barzilai Medical Center, Ashkelon, Israel. Address correspondence and reprint requests to Dr Nahlieli: Department of Oral and Maxillofacial Surgery, Barzilai Medical Center, Ashkelon 78306 Israel; e-mail: [email protected]
1. Stones that could be removed using an intraoral sialolithotomy approach, because they were usually located in the anterior part of the duct 2. Stones that could not be removed using the intraoral approach, such that extirpation of the entire gland, or sialoadenectomy, is necessary Another pathologic finding requiring gland removal was recurrent sialadenitis. The morbidity that occurs after traditional approaches for parotid and submandibular sialoadenectomy includes a number of complications. Neurologic
© 2010 American Association of Oral and Maxillofacial Surgeons
0278-2391/10/6802-0019$36.00/0 doi:10.1016/j.joms.2009.09.041
347
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COMBINED EXTERNAL LITHOTRIPSY AND ENDOSCOPY FOR SIALOLITHIASIS
FIGURE 1. Intraoperative view showing identification of parotid stone with help of a sialoendoscope and adaptation of a lithotripter applicator. Nahlieli, Shacham, and Zaguri. Combined External Lithotripsy and Endoscopy for Sialolithiasis. J Oral Maxillofac Surg 2010.
damage after superficial parotidectomy is a primary concern, because 16% to 38% of patients will develop temporary nerve weakness, and 9% will have permanent damage.2,3 During submandibular gland removal, a 7% risk of permanent marginal mandibular nerve damage and a 3% risk of damage to the lingual nerve exist.4 Frey’s syndrome, facial scarring, greater auricular nerve numbness, sialoceles, and salivary fistulas also contribute to the morbidity of the traditional procedure.3 During the past decade, rapid developments in technology, especially optical miniaturization, lithotripsy equipment, and micro-instruments, and the influence from other surgical fields, have directed us to develop new methods of treatment, including noninvasive, minimally invasive, and less-invasive procedures. Although we have been able to remove most salivary stones with the available techniques, we decided to combine these methods for advanced cases. We hypothesized that with this innovation, we would be able to solve more complicated cases without major surgery and perform the cases more easily and with a better success rate, with the return of the gland to normal function. In the present report, we assessed a combined lithotripsy-sialoendoscopy method developed for advanced salivary gland sialolithiasis cases using data from a prospective study.
present study for combined treatment. Of the 94 patients, 60 had pathologic features in the submandibular gland and 34 in the parotid gland. In contrast to small stones in the main salivary duct, the 5-mm stones located in the secondary ducts or intraparenchymally were considered to not be straightforward cases and, therefore, were included in the present study. The inclusion criteria were as follows. For the submandibular gland cases, patients were included if they had a small (⬍5 mm) stone in secondary ducts or intraparenchymal stone (n ⫽ 14 patients), a small (⬍5 mm) fixed stone in the main duct in the hilus region (n ⫽ 20 patients), or a medium to large (⬎5 mm) hilar or intraglandular stone attached to the surrounding tissue that was immobile or difficult to palpate (n ⫽ 26 patients). For the parotid gland cases, patients were included if they had a small (⬍5 mm) stone in the main or secondary duct proximal from the middle part of the duct (n ⫽ 8 patients), a small (⬍5 mm) stone in the secondary ducts or an intraparenchymal stone (n ⫽ 11 patients), or a medium to large (⬎5 mm) hilar or intraglandular stone attached to the surrounding tissue that was immobile or difficult to palpate (n ⫽ 15 patients). The exclusion criteria were similar for both locations and included small (⬍5 mm) mobile stones in the main duct and medium to large (⬎5 mm) hilar mobile palpable stones. The present prospective study was conducted according to the medical ethical regulations in Israel. All the combined parts of the treatment (lithotripsy, endoscopy, and endoscopic-assisted techniques) are well-known and accepted methods for sialolithiasis in Israel and Europe. TECHNICAL DATA
A miniature external lithotripter (extracorporeal shock wave lithotripsy; Sialotechnology, Ashkelon, Israel) was used in the present study. The technical details were as follows: electrohydraulic energy ⫺10 to 24 kV, miniature generator and applicator, focal
Materials and Methods PATIENTS
In the past 2 years, 94 patients (43 males and 51 females), aged 6 to 87 years were enrolled in the
FIGURE 2. View of 1.1-mm modular saliva scope with integrated grasping forceps. Nahlieli, Shacham, and Zaguri. Combined External Lithotripsy and Endoscopy for Sialolithiasis. J Oral Maxillofac Surg 2010.
349
NAHLIELI, SHACHAM, AND ZAGURI
FIGURE 3. A, Computed tomography scan of a 42-yearold man after failed endoscopic attempt to extract a sialolith identified in the right parotid gland showing a stone in the hilar region (arrow). B, Endoscopic view of a stone located near the hilum of the parotid gland in the secondary duct. C, Computed tomography scan of the same patient 1 month after the second session showing anterior movement of a stone to middle part of the Stensen’s duct (arrow). D, Intraoperative view of the patient during stone removal. Yellow arrow indicates original location of the stone, transillumination marked with yellow circle indicates new location of the stone near the Stensen’s duct orifice. E, Removal of the stone located near the Stensen’s duct orifice. Nahlieli, Shacham, and Zaguri. Combined External Lithotripsy and Endoscopy for Sialolithiasis. J Oral Maxillofac Surg 2010.
point depth ⫺15 ⫻ 15 ⫻ 25, large focus zone (focus at 50%) ⫺35 mm, and penetration depth ⫺120 mm. The diameter of the generator was not larger than a computer box, and the working head was reduced to
fit the dimensions of the head and neck region. The technique delivered 1,000 to 1,500 shock waves per session. An ultrasound transducer could be attached to the applicator head (Fig 1).
350
COMBINED EXTERNAL LITHOTRIPSY AND ENDOSCOPY FOR SIALOLITHIASIS
The endoscopic armamentarium included the modular salivascope system (PolyDiagnost GmbH, Pfaffenhofen, Germany), containing a telescope with 6,000pixel illumination fibers, a focal length of 2 to 15 mm, and a 70° field of view, was used. The diameter of the telescope was 0.5 mm (Fig 2). All the sleeves (0.9, 1.1, 1.6, and 2.0 mm) are disposable, and the optical part (the telescope) can be autoclaved. We used the PolyDiagnost Salivascope Flex (type PD ZS 2001, 1.1-mm, PolyDiagnost GmbH) all-in-one type endoscope with 6,000 pixels and 2 channels for surgical instruments and for irrigation. The instruments used for stone extraction with the endoscopic system included were stone grasping baskets miniforceps (PolyDiagnost GmbH) and high-pressure balloons (Sialotechnology). Finally, we also used the Sialoview MDI, 1.1-mm (Millennium, Islandia, NY), all-in-one type endoscope, with 6,000 pixels and 2 channels for surgical instruments and irrigation. The instruments used for stone extraction with the endoscopic system included stonegrasping baskets mini-forceps (PolyDiagnost GmbH), and high-pressure balloons (Sialotechnology). SURGICAL APPROACH
Ultrasonography and endoscopy were used to assist in locating the stone. The endoscope was then used to irrigate and inflate the salivary gland with isotonic saline and 2% lidocaine. External lithotripsy was then applied with low-energy levels up to 130 atm at 1,000 to 1,500 shock waves per session. Three sessions of extracorporeal shock wave treatment per patient were administered with a 1-month interval between each session. Because of the low energy of the shock waves, the procedure was not painful and did not require any anesthesia. After the results of lithotripsy, as assessed by plain radiographic sialography, ultrasonography, or computed tomography, either an intraductal endoscopic approach was used (pure endoscopic procedure) or an endoscopy-assisted extraductal approach was chosen (endoscopy-assisted technique). Thus, 3 types of treatment were performed: lithotripsy, lithotripsy plus intraductal endoscopy (pure endoscopy), or lithotripsy plus an endoscopic-assisted extraductal approach5-8 (a stretching procedure for the submandibular stones or an extraoral approach for the parotid stones). The second and third methods were used for patients in whom a salivary stone could not be eliminated using lithotripsy alone (Figs 3A-3E, 4A-4B, 5A-5D). The follow-up examinations were performed from 6 to 24 months postoperatively.
FIGURE 4. A, Panoramic view of a 40-year-old man with a deep left submandibular stone. He had experienced multiple episodes of swelling in the 2 years before his referral. B, Top, Radiograph showing original deep location of the stone (circle) posterior to the hilar region. B, Bottom, Radiograph showing stone location (circle) after 3 lithotripsy sessions. Note anterior movement of the stone. Nahlieli, Shacham, and Zaguri. Combined External Lithotripsy and Endoscopy for Sialolithiasis. J Oral Maxillofac Surg 2010.
Results Total elimination of the stone by lithotripsy alone was achieved in 30 patients (32%). In 27 patients, (29%), intraductal endoscopic assistance was needed. In 37 patients (39%), stone removal was achieved using the endoscopy-assisted extraductal approach. At 6 months of follow-up, all patients who had undergone lithotripsy or lithotripsy plus an intraductal endoscopic approach were symptom free. In the 37 patients in whom the endoscopy-assisted extraductal approach was used, 35 (95%) remained asymptomatic at 6 months postoperatively. Table 1 lists the results of treatment according to stone location and property. An unexpected positive side effect was detected after the combined treatment. Although it is not usually expected for the gland to return to normal func-
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FIGURE 5. A, Occlusal radiograph of a 32-year-old woman after failed attempt to remove a left submandibular stone showing a 5-mm stone inside the gland. Clinical evaluation revealed enlargement of the left submandibular gland with purulent secretion from the Wharton’s duct orifice. B, Occlusal radiograph after first lithotripsy session showing separation of the stone into 2 pieces. C, Occlusal radiograph after the third lithotripsy session showing 2 parts of the stone had moved anteriorly, one part to the anterior and one to the middle part of the Wharton’s duct. D, Endoscopic removal of the stone from the middle part of the Wharton’s duct. Nahlieli, Shacham, and Zaguri. Combined External Lithotripsy and Endoscopy for Sialolithiasis. J Oral Maxillofac Surg 2010.
tion in patients with long-standing, large-diameter stones, clinical observation showed a return of such glands to normal function. The effect was observed in 16 glands that had had large-diameter stones ⬎15 mm. This effect was detected during the 6 months of follow-up.
Discussion Until recently, the low success rate and very expensive equipment needed were the main obstacles pre-
venting surgeons from the use of the technique we have described. The rapid development in equipment miniaturization, the reduction in equipment costs, and the combination with other minimally invasive techniques have given this lithotripsy technique a place in our armamentarium for the treatment of sialolithiasis. The lithotripter we used generates enough substance to produce the cavitation effect. The success rate with this new lithotripter for the complete removal of stones was 32% in our study. Endoscopic removal
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Table 1. TREATMENT RESULTS STRATIFIED BY LOCATION, SIZE, AND SURGICAL METHOD
Treatment Location
Size
Submandibular Small (n ⫽ 60) Small, fixed Medium/large Parotid Small* (n ⫽ 34) Small† Medium/large‡
Lithotripsy Alone
IEA
EEA
Total
5 4 0 7 5 2
4 6 0 1 5 3
5 10 26 0 1 10
14 20 26 8 11 15
Abbreviations: IEA, intraductal endoscopic approach; EEA, endoscopy-assisted extraductal approach. *Small, ⬍5-mm stone in main or secondary duct proximal from middle part of duct. †Small, ⬍5-mm stone in secondary ducts or intraparenchymal. ‡Medium/large, ⬎5-mm hilar or intraglandular stone. Nahlieli, Shacham, and Zaguri. Combined External Lithotripsy and Endoscopy for Sialolithiasis. J Oral Maxillofac Surg 2010.
of the stones after the lithotripsy sessions was easier and less complicated. The shock waves disconnect the stone from the ductal wall and reduce the stone volume. The disconnection of the stone from the surrounding ductal tissue seems to be the major positive effect of the procedure. We believe that this combined lithotripsy-endoscopy approach could help to overcome the varying sizes, locations, and most of the obstructive conditions, because it involves multiple techniques and technologies (ie, pure endoscopy, endoscopic assistance, and external lithotripsy) that can be combined
A
in the treatment of a single patient. The implementation of these 3 methods relies on the advantages of each method and could lead to effective treatment of most of the obstructive and inflammatory conditions of the salivary glands. We decided to change the treatment philosophy of the lithotripsy procedure and to use it not as a solo technique but as an adjuvant technique. In the past, it was difficult to make endoscopy and endoscopy-assisted techniques easier and to achieve good results in advanced cases. With this insight, we adapted the miniature lithotripter and used low-energy levels to detach the stone from the tissue without breaking it into fragments. Disconnecting the outer cortex of the stone during or after lithotripsy and the positive effect on the formation of scar tissue has provided the possibility for saliva leakage to the oral cavity, bypassing the affected stone. Regaining normal gland function after lithotripsy in patients with medium to large stones appears to be a welcome addition to positive results of treatment. Additional research might be needed to evaluate this phenomenon; however, some speculations can be made. One could speculate that revascularization angiogenesis might occur in the affected salivary gland, similar to the effect of cardiac shock wave therapy. This might have been a suitable explanation, assuming that we used the same energy levels as were used for the cardiac shock wave research and treatment. Extracorporeal shock wave therapy has generated great interest in cardiology since the first report of enhanced neovascularization with shock wave application at the tendon– bone junction in a dog model.9
B B
A
Saliva leakage
S
Detachment
S Revascularization
Shock waves
FIGURE 6. A, Scheme of submandibular gland stone (S) during external lithotripsy. B, Scheme of same gland after external lithotripsy demonstrating 3 effects: detachment of stone, saliva leakage, and revascularization. Nahlieli, Shacham, and Zaguri. Combined External Lithotripsy and Endoscopy for Sialolithiasis. J Oral Maxillofac Surg 2010.
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It was then found that in patients with chronic refractory angina, extracorporeal shock wave therapy was safe and well tolerated. It improved symptoms, exercise capacity, and myocardial perfusion.10 Some evidence was shown in favor of the formation of new capillary networks.11 If this were also the case for salivary glands, the newly proposed treatment might add significantly to our therapeutic capacity in cases of sialolithiasis (Fig 6). Extracorporeal shock wave lithotripsy is an old technique with the main advantage of being noninvasive. The first report on the use of shock waves to fragment sialoliths was by Marmary12 in 1986. The problem at that time appeared to result from the large lithotripsy machine that was available, which had a very broad focus and caused the removal of dental fillings and periosteal irritation. The development of smaller machines with a more finely focused beam of waves led to additional improvement in the method, with a success rate of 50% to 60% for stone removal and up to 100% for symptom alleviation.13,14 It has not been previously used as an adjuvant technique with low levels of energy for the treatment of salivary gland diseases. Our innovation has demonstrated that it can be used in this field with significant success. The lithotripsy plus intraductal or extraductal endoscopic treatment of sialolithiasis is a highly effective surgical method for eliminating or removing salivary stones, especially deep and advanced sialolithiasis cases. This method can help to avoid resection of the salivary glands and represents an additional development in the minimally invasive surgical technique.
References 1. Rauch S, Gorlin RJ: Diseases of the salivary glands, in Gorlin RJ, Goldman HM (eds): Oral Pathology. St Louis, Mosby, 1970, pp 962-1070 2. Mra Z, Komisar A, Blaugrund SM: Functional facial nerve weakness after surgery for benign parotid tumours: A multivariate statistical analysis. Head Neck 15:147, 1993 3. Owen ER, Banerjee AK, Kissin M, et al: Complications of parotid surgery: The need for selectivity. Br J Surg 76:1034, 1989 4. Milton SM, Thomas BM, Bickerton RC: Morbidity study of submandibular gland excision. Ann R Coll Surg Engl 68:148, 1986 5. Nahlieli O, Shacham R, Zagury A, et al: The ductal stretching technique—Endoscopic assisted technique for submandibular stones. Laryngoscope 117:1031, 2007 6. Marchal F: A combined endoscopic and external approach for extraction of large stones with preservation of parotid and submandibular glands. Laryngoscope 117:373, 2007 7. Nahlieli O, London D, Zagury A, et al: Combined approach to impacted parotid stones. J Oral Maxillofac Surg 60:1418, 2002 8. McGurk M, MacBean AD, Fan KF, et al: Endoscopically assisted operative retrieval of parotid stones. Br J Oral Maxillofac Surg 44:157, 2006 9. Caspari GH, Erbel R: Revascularization with extracorporeal shock wave therapy: First clinical results. Circulation 100:84, 1999 (suppl 18) 10. Gutersohn A, Caspari G, Marlinghaus E: Autoangiogenesis induced by cardiac shock wave therapy (CSWT) increases myocardial perfusion in endstage CAD patients. Ch Z Kardiologiia 93:98, 2004 (suppl 3) 11. Fukumoto Y, Ito A, Uwatoku T, et al: Extracorporeal cardiac shock wave therapy ameliorates myocardial ischemia in patients with severe coronary artery disease. Coron Artery Dis 17:63, 2006 12. Marmary Y: A novel and non-invasive method for the removal of salivary gland stones. Int J Oral Maxillofac Surg 15:585, 1986 13. Iro H, Benzel W, Zenk J, et al: Minimally invasive treatment of sialolithiasis using extracorporeal shock waves. HNO 41:311, 1993 14. Zenk J, Bozzato A, Winter M, et al: Extracorporeal shock wave lithotripsy of submandibular stones: Evaluation after 10 years. Ann Otol Rhinol Laryngol 113:378, 2004