14.1
The Marchal Instruments
Salivary Endoscopy Relies on Several Factors
- 1.
The size of the papilla and the difficulty to pass the papilla without traumatizing it
- 2.
The caliber of the ducts
- 3.
The diameter of the scope
- 4.
The quality of the scope (number of pixels)
- 5.
The limitations of maneuvering the scope in the ductal system due to the anatomy (sharp angles) and to the scope (bendable or not)
- 6.
The correct visibility in the ductal system (that depends both on the rinsing system and on the tightness of the papilla) as the duct is naturally collapsed, similar to the esophagus.
Gundlach and colleagues, in 1990, developed the first flexible scope of 2.2 mm that had a fixed angled tip enabling 12 laser lithotripsy cases. The length and fragility of the scope hampered its development.
Katz, in 1991, performed the first stone extraction via a basket next to a nude optic fiber of 0.5 mm. The poor vision, the lack of rinsing, and inability to direct both the basket and optic fiber hampered its development.
Nahlieli and colleagues, in 1994, used a rigid optic fiber of 2.7 mm and baskets adjacent to the fiber on eight cases. There was a lack of a rinsing system and working channel, and this imposed a systematic marsupialization.
We started using a 1.6 mm flexible endoscope (mobile tip) with a working channel for rinsing and inserting baskets in 1995 . Although it was the first scope with both a rinsing and working channel, its fragility made its development impossible.
In 1997, Nahlieli and Baruchin started developing an interventional “sialendoscope” based on two tubes of 1.3 mm with a large handle and rinsing system . Its diameter corresponded to the diameter of the ducts (Zenk et al.), and length limited its use.
Our development of a specific “modular sialendoscope” occurred also in 1997. A line of diagnostic and interventional sheaths is adapted to thin optic fibers of 0.75 mm with working channels (WC) of 0.65 and 1.15 mm. A similar line for 1 mm optic fibers, with similar WC, a rinsing system around the optic fiber, and a beveled tip allowed progressive dilatation of the papilla ( Fig. 14.1.1 ). The fibers are semiflexible, and they can follow any curve that has been previously applied to the sheaths, in order to explore sharp angled bifurcations. The first 100 cases were published in the New England Journal of Medicine (NEJM) in 1999.
The noninvasive passage of the papilla being the limiting factor, we developed specific instruments to dilate the papilla atraumatically. We focused starting in 2001, teaching the technique in our European Sialendoscopy Training Center. The importance of papilla dilators, conic dilators, hollow dilators introduced over guidewires, as well as scissors and grasping and biopsy forceps (all instruments that were developed in collaboration with the Karl Storz Co., Tuttlingen, Germany) enabled a reproducible technique ( Fig. 14.1.2 ).
Regarding disposables, as there were no small diameter baskets and balloons, we developed baskets of three, four, and six wires (0.6 and 0.4 mm diameter) with and without tip as well as balloons (0.7 and 0.9 mm) microburrs and guidewires (0.38, 0.4, and 0.6 mm) fitting our sialendoscopes ( Fig. 14.1.3 ), and looked for laser fibers of similar sizes, enabling endoscopic controlled intraductal lithotripsy of stones.
Later in 1999, the Karl Storz Co. produced what we named the “all-in-one scopes,” including optics and light, rinsing channels (RC), and WC in a single tube. To be able to treat children and small ducts, as well as adults, we requested several diameters: 0.89 mm (WC or RC 0.25); 1.1 mm (WC 0.45, RC 0.25); 1.3 mm (WC 0.65, RC 0.25); and 1.6 mm (WC 0.8, RC 0.25).
All the scopes have markings for each centimeter and a bent tip of 5°, as we have noticed that exploration of the ductal system requires a rigid bend of the tip of the scope ( Fig. 14.1.4 ). Both systems, for 20 years, have been used to treat patients with salivary stones and strictures.
Nahlieli and Baruchin later developed the same principle of a straight “sialoscope,” with disposable sheaths and a flexible optic fiber. In 2004, the Erlangen group using also a similar sialoscope published their first 24 sialendoscopy cases. In 2007, the Karl Storz Co. developed, with the Erlangen group, similar sialendoscopes to our “all-in-one” scopes (0.89 mm, 1.1 mm, 1.6 mm) with a different material, nitinol, allowing total flexibility of the scope but no definite bending of its tip.
Having used both systems for almost 20 years, the modular scope system appears, in our opinion, to be slightly less fragile, with a superior image quality due to an increase in pixels for an identical size. It is also more efficient to explore the entire ductal system due to the customizable bending of its tip and to dilate strictures with the beveled tip. This customization is impossible with “all-in-one scopes”: Marchal models do have a fixed angle of 5°, which facilitates exploration but is not bendable, and the Erlangen scopes do not have a bent tip, as it is flexible but not bendable.
It is important to say that all the scopes existing on the market (at time of writing) are extremely fragile. The fragility is not only linked with the tip of the endoscope but also with the cable, that contains the optic fibers and the light fibers. The sterilization process is one of the keys to its duration.
14.2
The Erlangen Set
Investigation of salivary ducts with endoscopes was first described by Königsberger in 1990 and Katz in 1990. These flexible endoscopes caused minimal trauma owing to their small diameter and flexibility. Image quality was unsatisfactory due to their poor optical properties and the absence of an irrigation channel in many instruments. Rigid endoscopes, derived from urology, were used later by Nahlieli et al. and provided better optical quality but caused greater trauma to the duct epithelium. To combine the advantages of both types, semirigid or semiflexible endoscopes were developed. These instruments have a smooth, flexible, atraumatic outer sheath ( Table 14.2.1 ). Zenk et al. examined the diameters of the salivary duct in anatomic specimens. His study indicated that the parotid and submandibular ducts each had an average diameter of 1.5 mm. The parotid duct orifice had an average diameter of 0.5 mm, and the submandibular duct orifice measured 0.1–0.5 mm. It was concluded that sialendoscopes with an outer diameter of 0.7–1.7 mm should be suited for all the major salivary ducts. Erlangen sialendoscopes were developed based on our own clinical experience and basic research (Karl Storz; Fig. 14.2.1 , Table 14.2.1 ). All the endoscopes can be sterilized with standard disinfectant solution or gas/plasma sterilization. Sialendoscopes and instruments can be stored on a metal tray.
| Author (Year) | Sialendoscope (Type) | Sialendoscope (Diameter) | 1. Channel (Diameter) | 2. Channel (Diameter) |
|---|---|---|---|---|
| Königsberger (1990) | Flexible | – | – | – |
| Katz (1990), (1991) | Flexible | 0.8 mm | – | – |
| Gundlach (1994) | Flexible | 2.0 mm | 0.6 mm | – |
| Nahlieli (1994) | Rigid | 2.7 mm | – | – |
| Iro (1995) | Flexible | 1.6 mm | 0.6 mm | – |
| Ito (1996) | Flexible | 1.5 mm | 0.2 mm | – |
| Arzoz (1996) | Rigid | 2.1 mm | 1.0 mm | – |
| Marchal (1997) | Flexible | 1.5 mm | 0.5 mm | – |
| Yusua (1997) | Flexible | 0.8 mm | – | – |
| Rigid | 1.8 mm | – | – | |
| Nahlieli (1997) | Rigid | 2.0 mm | – | – |
| Rigid | 2.5 mm | 1.0 mm | – | |
| Marchal (1998) | Semiflexible | 1.3 mm | 0.8 mm | – |
| Semiflexible | 2.67 mm 2 | 0.8 mm | – | |
| Nahlieli (1999) | Semiflexible | 1.3 mm | 1.0 mm | – |
| Semiflexible | 2.3 mm × 1.3 mm | 1.0 mm | yes | |
| Iro (2000) | Semiflexible | 1.1. mm | 0.4 mm | – |
| Semiflexible | 1.2 mm | 0.6 mm | yes | |
| Marchal (2001), (2002) | Semiflexible | 1.3 mm | 0.8 mm | yes |
| Semiflexible | 2.29 mm 2 | 0.8 mm | yes | |
| Zenk (2004) | Semiflexible | 1.1 mm | 0.4 mm | yes |
| Semiflexible | 1.38 mm | 0.8 mm | yes | |
| “Erlangen-Set” (2004–2007) | Semiflexible | 0.8 mm | 0.25 mm | – |
| Semiflexible | 1.1 mm | 0.45 mm | 0.25 mm | |
| Semiflexible | 1.6 mm | 0.85 mm | 0.25 mm |
The Erlangen set of sialendoscopes currently consists of three different sialendoscopes and includes specific features. The image transmission system has a resolution of 6000–10,000 pixels. The optical cable and telescope can be connected to a standard cold light source and video system. The sialendoscopes have 0° forward-view optics. The eyepiece is offset, has built-in fiberoptics, and is 140 cm long. The sialendoscopes have a specific designed handpiece suitable for economic handling of the device. The outer sheath of the endoscopes is made of nitinol to provide adequate flexibility. The useful length is at least 10 cm and markings are placed at 1 cm intervals along the outer sheath.
The diameter for the sialendoscope for diagnostic purposes is 0.8 mm. The sheath contains the optical channel and one channel for irrigation with a diameter of 0.25 mm ( Fig. 14.2.1A ). The nitinol sheath provides flexibility to a nearly 90° angle. The set of endoscopes includes two sialendoscopes for diagnostic and interventional purposes, which have a diameter of 1.1 and 1.6 mm. The 1.1 mm ( Fig. 14.2.1B ) sialendoscope has a working channel of 0.45 mm included within the sheath, which allows insertion of small instruments with adequate diameters like various baskets, microdrill or laser fiber. This sialendoscope can be bent to about 40–50°. The 1.6 mm sialendoscope permits larger instruments with a diameter of the working channel of 0.85 mm. The larger microdrill and various kinds of forceps (diameter 0.78 mm each) make more effective interventional therapy possible. The sheath is firmer so that flexibility is limited to about 30°. The different diameters and centimeter markers on the shaft of the sialendscopes are of particular importance in the diagnosis and classification of stenosis. These parameters are important for sialendoscopic-based classification of stenosis. The narrow duct orifice must allow entry of the endoscope, and generally this requires expanding the orifice with a dilator ( Fig. 14.2.1B ).
Several wire baskets with a working length of 20 cm differ in size, tip, and handle. The smaller baskets have an outer diameter of 0.38 mm and four wires; the larger baskets are 0.78 mm and come with three, four, or six wires. They can have a handle by which the basket is opened and closed; alternatively, the basket is opened and closed passively when pulled back into the sheath. If the basket has a tip, it can be welded or twisted. Tipless baskets allow a more atraumatic removal of stones or fragments ( Figs. 14.2.2B , 14.2.3 ). All baskets are useful for extracting stones, plaques, or foreign bodies; however, only those with a tip ( Fig. 14.2.2A ) can be used to open stenoses.
