[Endonasal frontal sinus surgery. Part 2: Frontal sinus drainage type III (median drainage), tips and tricks, postoperative care]

[Local flap reconstruction techniques after frontal sinus drainage type II and III according to Draf]

BACKGROUND

Extended endonasal endoscopic frontal sinus surgery is characterized by bone resection beyond the lamellae of the frontal sinus and is currently classified according to Draf as type IIa, type IIb, modified type III (also referred to as type IIc), and type III. This approach is indicated when the surgical goal cannot be achieved through complete removal of the anterior ethmoidal cells. Numerous studies indicate restenosis rates ranging from 7 to 36%, despite creation of maximal openings. Exposed bone, which tends to epithelize slowly with significant crusting and the risk of uncontrolled wound healing depending on the local environment and other factors, is considered a contributing factor. Covering the exposed bone with mucosa can significantly reduce the risk of restenosis.

METHODS AND RESULTS

A variety of flap techniques for frontal sinus drainage in Draf III procedures are presented, including some variants that were part of presentations at the 2023 Congress of the European Rhinologic Society in Sofia, Bulgaria. These include combinations of free mucosal grafts, pedicled mucosal flaps, and hybrids combining both techniques. Additionally, the results of current studies are presented.

CONCLUSION

The results and achieved opening areas in contemporary Draf III surgeries are significantly improved and larger compared to the early stages of these procedures. A multitude of published studies consistently demonstrate that outcomes are markedly improved with mucosal coverage. Depending on the prevailing anatomy, mucosal conditions, and the extent of the surgical intervention, the most suitable technique should be selected. Therefore, proficiency in various methods is crucial. The use of a flap technique (free, pedicled, or combinations thereof) should be defined as the standard when performing extended frontal sinus surgery (Draf IIb, IIc, III, or endonasal frontal sinus surgery [EFSS] 4-6).

Comprehensive review on endonasal endoscopic sinus surgery

Endonasal endoscopic sinus surgery is the standard procedure for surgery of most paranasal sinus diseases. Appropriate frame conditions provided, the respective procedures are safe and successful. These prerequisites encompass appropriate technical equipment, anatomical oriented surgical technique, proper patient selection, and individually adapted extent of surgery. The range of endonasal sinus operations has dramatically increased during the last 20 years and reaches from partial uncinectomy to pansinus surgery with extended surgery of the frontal (Draf type III), maxillary (grade 3-4, medial maxillectomy, prelacrimal approach) and sphenoid sinus. In addition there are operations outside and beyond the paranasal sinuses. The development of surgical technique is still constantly evolving. This article gives a comprehensive review on the most recent state of the art in endoscopic sinus surgery according to the literature with the following aspects: principles and fundamentals, surgical techniques, indications, outcome, postoperative care, nasal packing and stents, technical equipment.

[Advances in the surgical treatment of tumors of the pituitary region : rhino-neurosurgical transnasal endoscopic surgery]

Conventional microscopic surgery of pituitary adenomas offers excellent results with regard to local tumour control and endocrine function. Overall patient morbidity and mortality is low. However, recent studies demonstrate further improvements in tumour resection control and more favourable endocrine/ophthalmologic results when endoscopic techniques are applied, as well as an overall reduction in peri-interventional morbidity. Additionally, use of endoscopic techniques in rhino-neurosurgical cooperation achieved better specifically rhinologic results and improved subjective comfort for patients. The cooperative rhino-neurosurgical approach not only allows for optimal treatment of the primary pituitary pathology, but also treatment of additional nasal and paranasal pathologies, such as a deviated septum or disturbed drainage of the paranasal sinus.

Biodegradation of metallic magnesium elicits an inflammatory response in primary nasal epithelial cells

Resorbable magnesium-based implants hold great promise for various biomedical applications, such as osteosynthesis and coronary stenting. They also offer a new therapeutic option for the treatment of chronic rhinosinusitis, but little data is yet available regarding the use of magnesium in the nasal cavity. To model this field of application, primary porcine nasal epithelial cells were used to test the biocompatibility of degrading pure magnesium and investigate whether the degradation products may also affect cellular metabolism. Magnesium specimens did not induce apoptosis and we found no major influence on enzyme activities or protein synthesis, but cell viability was reduced and elevated interleukin 8 secretion indicated proinflammatory reactions. Necrotic damage was most likely due to osmotic stress, and our results suggest that magnesium ion build-up is also involved in the interleukin 8 release. Furthermore, the latter seems to be mediated, at least in part, by the p38 signaling pathway. These effects probably depended on the accumulation of very high concentrations of magnesium ions in the in vitro set-up, which might not be achieved in vivo, although we cannot exclude that further, as yet unknown, factors played a role in the inflammatory response during the degradation process. In conclusion, the biocompatibility of pure magnesium with cells in the immediate vicinity appears less ideal than is often supposed, and this needs to be considered in the evaluation of magnesium materials containing additional alloying elements.

Endoscopic frontal sinus drainage Draf type III with mucosal transplants

BACKGROUND

This study was designed to evaluate the extent of restenosis that occurs after an endoscopic frontal sinus drainage Draf type III (Draf III; modified Lothrop procedure) using a modified technique with reconstruction of the frontal sinus drainage pathway with mucosal transplants, in combination with occlusive postoperative care.

METHODS

Retrospective case series was performed with 24 consecutive patients undergoing Draf III drainage between 2005 and 2010 using the modified technique of covering the bare bone with mucosal transplants from the nasal septum. To ensure optimal moist wound healing, occlusion of the nose was realized by taping the nose for 2 weeks postoperatively. Frontal ostium measurements were done intraoperatively and at follow-up visits for a minimum of 12 months. Data on patient history, demographics, comorbidities, and computed tomography scans were collected.

RESULTS

Mean follow-up was 25.6 months. Eight patients were lost to follow-up. Ninety-four percent of frontal sinus neo-ostia remained open. One patient needed revision surgery using an osteoplastic flap with obliteration. The frontal neo-ostium narrowed by an average of 36.9% from 20.5 × 12.5 to 15 × 9.6 mm. On average, three visits were needed for postoperative care. The patients did not experience significant pain throughout the postoperative healing time.

CONCLUSION

The modified Lothrop procedure is a well-established technique in endoscopic sinus surgery to handle difficult frontal sinus drainage pathways or revision surgeries. The modified technique provides good results in combination with minimized postoperative care and morbidity. A comparative study would be necessary to show superiority to the standard method of Draf III.

The use of an in vitro-cultured porcine nasal mucosa model for the biocompatibility assessment of biodegradable magnesium

The development of an in vitro-cultured porcine nasal mucosa model is described. The model was subsequently used for the biocompatibility testing of resorbable magnesium-based implants, which are intended for use in the nasal cavity of patients with chronic rhinosinusitis (CRS). Test specimens made from either pure magnesium or titanium were incubated with the mucosal tissue for 48 hours. Afterwards, tissue viability, PGE2, IL-6 and IL-8 release, magnesium ion release, succinate dehydrogenase activity, apoptosis and 14C amino acid incorporation, were determined. The results suggested favourable biocompatibility, even in the case of rapidly-degrading pure magnesium. However, presumed effects on protein synthesis and apoptosis could not be confirmed.

Nasal packing and stenting

Nasal packs are indispensable in ENT practice. This study reviews current indications, effectiveness and risks of nasal packs and stents. In endoscopic surgery, nasal packs should always have smooth surfaces to minimize mucosal damage, improve wound healing and increase patient comfort. Functional endoscopic endonasal sinus surgery allows the use of modern nasal packs, since pressure is no longer required. So called hemostatic/resorbable materials are a first step in this direction. However, they may lead to adhesions and foreign body reactions in mucosal membranes. Simple occlusion is an effective method for creating a moist milieu for improved wound healing and avoiding dryness. Stenting of the frontal sinus is recommended if surgery fails to produce a wide, physiologically shaped drainage path that is sufficiently covered by intact tissue.