Chapter 28 Palatal implants for primary snoring: short- and long-term results of a new minimally invasive surgical technique
1 INTRODUCTION
Snoring is a widespread symptom affecting about 50% of the adult population. Primary snoring without sleep disordered breathing is not harmful in itself. However, as snoring often causes social embarrassment and marital disharmony, affected patients apply to their physicians for treatment.
Therefore, both patients and physicians prefer a minimally invasive and less painful procedure as a primary option for the treatment of snoring. Since its invention in 1998 interstitial radiofrequency treatment of the soft palate has gained increasing interest among the public because it was the first minimally invasive surgical treatment bearing a low morbidity as well as a remarkable success rate.1 However, it is not a single-step procedure and treating the palate excessively may still impair the various functions of the soft palate in very few cases. Furthermore, a considerable relapse of snoring 1 to 1½ {} years after the last radiofrequency treatment has to be considered.2 Due to this relapse of snoring, alternative therapies with minimal morbidity and long-term efficacy are desired. Therefore, a new procedure was developed in 2001 where woven cylindrical implants are placed within the soft palate in order to stiffen the soft palate and thus reduce snoring. These implants are made of polyethylene terephtalate, a material which has been used in heart valve surgery for the last decades.
In this chapter, the patient selection criteria for the insertion of palatal implants in the treatment of snoring and its success rate as well as its morbidity are described according to the literature and to our own experience. The procedure is described in detail. It is performed identically in snorers as well as sleep apnea patients. During the last few years the delivery tool has been modified three times. It became smaller and contains more safety precautions against unwanted or incorrect implant deployment (Fig. 28.1).
2 PATIENT SELECTION
The Pillar® procedure consists of inserting implants into the junction of hard and soft palate in order to extend the hard palate, thus reducing the vibrating parts of the palate. The nature of the procedure where there is no resection or ablation of palatal tissue makes the patient selection criteria for this operation comprehensible. Patients with the following findings at the upper pharyngeal level should not receive palatal implants as a solitary intervention: nasal obstruction for whatever reason, distance between both tonsils less than 2 cm, excessive palatal and pharyngeal mucosa, and an uvula longer than 1 cm (Fig. 28.2). Patients with signs of tongue base snoring or obstruction in the clinical examination such as Friedman Tongue Position 3 or 4 (Fig. 28.3), tongue base hypertrophy, retrognathia, and floppy epiglottis are also not suitable candidates for this procedure. Obesity with a BMI above 32 kg/m² is known to impair any surgical intervention at the upper pharyngeal level and therefore is considered to be an exclusion criterion. In brief, patients without any obvious morphological anomaly in their nose and pharynx except a sufficiently long soft palate are suitable candidates for a solitary Pillar® procedure (Fig. 28.4). It has to be kept in mind that in all publications concerning the efficacy of palatal implants themselves, only those patients who fulfilled the above-mentioned inclusion criteria were treated.
The impact of nasal obstruction on snoring can be easily detected by applying a nasal decongestant and/or a nasal dilator before bedtime for a period of 7 days. If the improvement of nasal breathing during the night does not lead to a decrease of snoring, a combined versus a stepwise operation of the nose and the Pillar® procedure may be discussed with the patient. Of course, an adjunct conservative treatment with a mandibular advancement device, positional therapy, and/or weight reduction is possible at any time and vice versa. It is well documented in sleep apnea patients that palatal implants can be inserted synchronously to or as a second step after other soft palate procedures like UPPP.3 It is also possible in the case of a recurrence of symptoms after such operations.4 Future studies have to show whether this is also true for primary snorers. Radiofrequency of the soft palate, injection snoreplasty, and cautery-assisted palatal stiffening operations are not recommended as additional surgeries by us, because the tissue necrosis they induce is likely to increase the risk of implant extrusion and infection (see Complications below). There are no data concerning the combination with tongue base procedures (i.e. radiofrequency, laser resection of the lingual tonsil, genioglossus advancement, hyoid suspension), but obviously there is no surgical contraindication as different anatomical sites are addressed. However, tongue base procedures are rarely used in primary snoring anyway.
If palatal implants are used as additional surgery, one will lose the minimally invasive character of the intervention in most cases. Therefore, it has to be investigated whether the indication for an isolated Pillar® procedure may generally be extended to patients considered less suitable up to now, in order to offer this minimally invasive procedure as a real alternative to more aggressive operations as mentioned above. Furthermore, it is not yet clear whether additional methods for the assessment of the site of snoring sound generation can improve the selection process towards a better outcome. Regarding this issue, sound analysis using the SNAP®system did not increase the success rate.5 Multi-channel pressure recordings during natural sleep and videoendoscopy during wakefulness as well as under sedation are still under investigation.
The implant is a braided segment of polyester filaments intended for permanent implantation. The implant is 18mm in length and has an outer diameter of 1.5mm. The delivery tool (See Fig. 28.1
