Image-Guided Sinus Surgery

Cerebrospinal fluid (CSF) rhinorrhea is a sign of a breach in the bony skull base. It should be verified, localized, and repaired surgically to alleviate the risk of intracranial infection. Endonasal endoscopic surgery is the standard technique for skull base reconstruction in these patients. The current study was undertaken to evaluate a large case series of patients with CSF rhinorrhea who underwent surgery, focusing on symptoms, etiology, specifics of skull base defects, reconstruction techniques, outcomes, and complications. All patients with CSF rhinorrhea who were treated endoscopically for a skull base defect from 2010 to 2023 in a tertiary referral hospital were included. In this retrospective study, 263 patients were included. The chief presenting symptom was rhinorrhea. Spontaneous CSF leak was the most common etiologic factor, whereas accidental trauma accounted for about one-third of the cases. In cases of spontaneous CSF rhinorrhea, the most common sites of skull base defects were the cribriform plate, lateral lamella of the ethmoid, and the lateral recess of the sphenoid. The frontal sinus was the most common site of defect in cases of accidental traumatic CSF rhinorrhea. In the majority of cases, a two-layer technique using inlay fat and onlay fascia was employed for skull base reconstruction. Recurrences, including technical failures, missed skull base defects, and late new skull base defects, were observed in 10 cases (3.8%). Three patients developed meningitis in the early postoperative period, but all recovered uneventfully. Given the high success rate and low morbidity, all patients with CSF rhinorrhea should be counseled to undergo endoscopic surgery early.

Endoscopic endonasal anterior skull base surgery is currently applied for the treatment of olfactory neuroblastoma, and other skull base lesions. In the surgical approach to the anterior skull base, one of the important step is extended frontal sinus surgery, including modified endoscopic Lothrop procedure (MELP). Surgical simulation using artificial three dimensional (3D) models is known to a useful training method to learn the surgical steps and to gain the surgical skills. In this study, we investigated the usefulness of a 3D head model with the detailed CT information in the surgical simulation for extended frontal sinus surgeries and anterior skull base resections. 3D head models (KEZLEX, Ohno, Japan) were used as a surgical simulator. This model is exactly reconstructed and made as a human head including sinonasal structure and anterior/posterior skull base by 3D printer. In this model, we made the first olfactory nerve with a steel wire at the skull base as the posterior limit of the frontal sinus flour to the skull base. In addition, the head model was examined for surgical anatomy by using the cone-beam CT (Accuitomo, Morita, Japan). Then, endoscopic endonasal surgery was performed using a high speed bur (M5, Medtronic, Japan) for the bone resection guided with a navigation system (Fusion, Medtronic, Japan). MELP was performed according to the surgical steps of the outside-in frontal drill-out technique. In results, MELP and the anterior skull base resection including crista galli were successfully performed for 3D model with CT and the navigation. These findings suggest that surgical simulation using artificial 3D head model and cone beam CT combined with a navigation system is useful in the surgical training for endoscopic endonasal anterior skull base surgery.

The purpose of this randomized, prospective study was to compare accuracy in tunnel placement as performed with a traditional arthroscopic anterior cruciate ligament (ACL) reconstruction technique and with KneeNavTM ACL, a computer-assisted surgical navigation technique. Two surgeons experienced in ACL reconstruction, but inexperienced in computer-assisted surgical navigation technique, each randomly used traditional arthroscopic guides or KneeNavTM ACL to drill a tunnel in twenty identical foam knees. Placement of the resulting tibial and femoral tunnels was measured with a computer-assisted digitizing method and compared to traditional biplanar radiographs. Statistical analysis with Student's t-test was used to compare the distance from the ideal tunnel placement to the femoral and tibial tunnels. Accuracy of tunnel placement with KneeNavTM ACL was significantly better than that obtained with the traditional arthroscopic technique. Distances from the ideal tunnel placement to the femoral and tibial tunnels were 4.2 +/- 1.8 mm (mean +/- SD) and 4.9 +/- 2.3 mm, respectively, for the traditional arthroscopic technique, and 2.7 +/- 1.9 mm (femur) and 3.4 +/- 2.3 mm (tibia) for KneeNavTM ACL. These differences were statistically different. Tunnel placement for ACL reconstruction with KneeNavTM ACL, an image-based, computer-assisted surgical navigation device with a simple and intuitive interface, was more accurate than with the traditional arthroscopic technique.

Endoscopic sinus surgery with and without computer assisted navigation: A retrospective study

Efficacy of a 5-day course of telithromycin in the treatment of acute maxillary sinusitis caused by drug-resistant Streptococcus pneumoniae

This study evaluates the management of frontal sinus disease using osteoplastic flap surgery (OPFS) in the current era of image-guided endoscopic sinus surgery (IGESS). A retrospective chart review was performed of patients who underwent OPFS and imaged-guided endoscopic frontal sintus surgery in the past 10 years at a tertiary care teaching hospital. Chart reviews of clinic patients and inpatients who underwent OPFS were performed. Indications for surgery, prior sinus surgeries, time to OPFS, post-OPFS sinus surgeries, and associated comorbid factors were reviewed. In the period under review, 710 IGESS cases were performed. Thirty patients, who were candidates for OPFS, underwent IGESS for frontoethmoid disease. Fourteen patients from this group failed IGESS and underwent OPFS. The indications for OPFS included mucocele in 10 cases, tumors in 2 cases, and trauma in 2 cases. Four patients underwent revision OPFS. The patients who failed IGESS had prior trauma, tumor resection, radiation, or large septate frontal sinus with lateral extension in which the mucocele could not be drained endoscopically. The average time to OPFS was 6.2 years (0-27 years). Nine patients had prior sinus surgery (1-7 prior surgeries) and five patients had subsequent endoscopic surgical procedures. In all patients with frontal mucocele, surgery should be attempted endoscopically using IGESS because of the low morbidity of the procedure. Patients with risk factors for failure should be considered for OPFS if IGESS proves to be unsuccessful.

The anatomic variation of the frontal sinus and frontal recess can create both a diagnostic and therapeutic challenge. Most cases of frontal sinus disease can now be treated by endoscopic approaches. For refractory cases or those with severe pathology, the microscopically controlled drainage (MCD) operation has at times been successful and spared the patient the morbidity of an external approach. The aim of this study was to evaluate microscopically controlled frontal sinus surgery in these difficult cases. Prospective analysis was performed on the efficacy of MCD in patients for whom endoscopic sinus surgery had failed or in primary cases with severe pathology or unfavorable anatomy. The technique employs a self-retaining endonasal retractor and a diamond bur under microscopic visualization to remove solid bone (frontal spine) obstructing the sinus drainage and allow a wide opening of the frontal recess while causing minimal mucosal damage. Unilateral drainage (extended frontal sinus drainage operation), and in some cases bilateral drainage (median drainage procedure) is employed. With an average of 23 months of follow-up, over 90% of patients were either free of symptoms or substantially improved after the MCD procedure. Three patients required revision surgery (extend the opening into a median drainage procedure) for adequate relief of symptoms. The MCD procedure is highly successful in the treatment of frontal recess disease, particularly in those cases of severe pathology or difficult anatomy. It may be used in those cases refractory to standard endoscopic sinus surgery where an external approach and frontal sinus obliteration are contemplated. As with endoscopic sinus surgery, precise knowledge of the frontal recess and neighboring landmarks is critical, and adequate drainage with minimal mucosal disruption should be the goal.

Can sinus anatomy predict quality of life outcomes and operative times of endoscopic frontal sinus surgery?

The surgical treatment of frontal sinus fractures is foreshadowed by fears of late complications. Complications such as meningitis and mucoceles should be prevented by cranialization or obliteration of the frontal sinus. These procedures are still standard treatment despite of recent developments over the last two decades in endoscopic sinus surgery, in medical imaging and surgical instrumentation. Nowadays the role of cranialization and obliteration is challenged by refined endoscopic frontal sinus surgery techniques, the widely-used image-guided systems and the multiplanar high-resolution computed tomography along with new data about postoperative complications. This overview summarizes the current literature, taking into account the existing evidence in the treatment of frontal sinus fractures.

Image-guided sinus surgery

Cerebrospinal fluid leakage is always the primary complication during the endoscopic endonasal skull base surgery. Dural suturing technique may supply a rescue method. However, suturing and knotting in such a deep and narrow space are difficult. Training in the model can improve skills and setting a stepwise curriculum can increase trainers' interest and confidence. We constructed an easy model using silicone and acrylic as sphenoid sinus and using the egg-shell membrane as skull base dura. The training is divided into three steps: Step 1: extracorporeal knot-tying suture on the silicone of sphenoid sinus, Step 2: intra-nasal knot-tying suture on the same silicone, and Step 3: intra-nasal egg-shell membrane knot-tying suture. Fifteen experienced microneurosurgical neurosurgeons (Group A) and ten inexperienced PGY residents (Group B) were recruited to perform the tasks. Performance measures were time, suturing and knotting errors, and needle and thread manipulations. The third step was assessed through the injection of full water into the other side of the egg to verify the watertight suture. The results were compared between two groups. Group A finishes the first and second tasks in significantly less time (total time, 125.1 ± 10.8 vs 195.8 ± 15.9min) and fewer error points (2.4 ± 1.3 vs 5.3 ± 1.0) than group B. There are five trainers in group A who passed the third step, this number in group B was only one. This low cost and stepwise training model improved the suture and knot skills for skull base repair during endoscopic endonasal surgery. Experienced microneurosurgical neurosurgeons perform this technique more competent.

Background The frontal sinus is among the most anatomically complex regions to manage in endoscopic sinus surgery, with high risks of postoperative restenosis. This study aimed to evaluate the safety and efficacy of biodegradable, drug-eluting stents (Propel) compared to traditional non-drug-eluting stents (Merocel and Rains) in maintaining frontal sinus ostium patency following functional endoscopic sinus surgery (FESS). Methods A prospective comparative study was conducted at Helwan University Hospital (Badr Hospital), enrolling 34 adult patients with various frontal sinus pathologies at high risk of restenosis. Participants were randomized into two groups: the study group ( n = 17) received the Propel stent, while the control group ( n = 17) received either Merocel or Rains stents. Patients were followed for 6 months postoperatively with clinical, endoscopic, and radiological assessments. Primary outcomes included frontal ostium patency, while secondary outcomes assessed complications such as stenosis, obstruction, adhesions, polyp formation, mucosal healing, and inflammation. Results Baseline characteristics and surgical indications were comparable between groups. At 6 months, the Propel group demonstrated significantly higher ostium patency (100% vs. 41.18%, p = 0.001), a complete absence of adhesions (0% vs. 58.82%, p = 0.001), and lower rates of polyp formation (0% vs. 23.53%, p = 0.033). Sinonasal mucosal healing was higher in the Propel group (94.12% vs. 76.47%, p = 0.168), though not statistically significant. Trends toward reduced inflammation and retained secretions favored the Propel group. All Propel stents were entirely absorbed by 6 months without the need for removal. Conclusion Biodegradable drug-eluting Propel stents significantly improve postoperative outcomes in frontal sinus surgery by enhancing ostium patency, reducing adhesions and polyp recurrence, and promoting mucosal healing. These findings support the selective use of drug-eluting stents in high-risk patients; however, larger multicenter trials with longer follow-up are needed to confirm the long-term benefits.

Long-term results of endoscopic frontal sinus surgery

INTRODUCTION The most frequent complication of endoscopic endonasal surgery (EES) is postoperative cerebrospinal fluid (CSF) leak. This study was designed to develop a step-wise algorithm for EES reconstruction across the spectrum of skull base defects: from free mucosal graft for uncomplicated pituitary adenomas to free flaps in complex cases with recurrent leaks. METHODS All patients with skull base pathologies who underwent EES between January 2017 and December 2018 were included and retrospectively analyzed. Tumor location, reconstruction method and postoperative CSF leak were reviewed and a step-wise algorithm based on size and location of defect was developed. RESULTS Location of skull base defects was categorized as follows: anterior fossa, suprasellar, sellar and posterior fossa. For all nonsellar sites, we performed a multilayer (collagen matrix + /- fascia lata + /− fat graft + vascularized flap) reconstruction. The nasoseptal flap (NSF) was the first choice for vascularized reconstruction when available. For all sellar lesions we employed a free mucosal graft unless a high-flow CSF leak was present, in which case a single-layer reconstruction with NSF was performed. When the NSF was not available, alternative local (lateral nasal wall flap) and regional (extracranial pericranial flap) pedicled flaps were successful choices. When patients failed multiple attempts at repair, regional or microvascular free flaps were options. Lumbar spinal drainage was employed for large anterior and posterior fossa defects and during secondary repair of postoperative CSF leaks. Of 347 patients, 4.6% had a postoperative CSF leak. Of 158 patients with an intraoperative leak (45.5%), 10.1% developed a postoperative CSF leak: 7.8% for sellar/suprasellar defects and 13% for anterior/posterior fossa defects. CONCLUSION This algorithm provides a standardized, stepwise approach to the reconstruction of all skull base defects after EES based on location.

Endoscopic endonasal surgery is a well-established surgical approach to the skull base. Surgeons need a reusable long-lasting tool to acquire the skills needed for skull base reconstruction. The aim of this study was to elaborate and validate a human formalin-fixed cadaveric model that reproduces a realistic cerebrospinal fluid (CSF) circulation and that adequately renders a CSF leak. An external ventricular drain that connects with a peristaltic pump is placed in the subarachnoid space, which allows a water circulation that reproduces CSF circulation. Intracranial pressure is measured in real time. Endoscopic endonasal skull base approaches are performed, to create different skull base openings and CSF leaks. Participants were tasked with reconstruction of the defects using a standardized multilayered approach, with the goal of obtaining a watertight closure under normal intracranial pressure ranges. Compiled data included time of reconstruction, years of experience of participants, and success/failure to achieve a watertight reconstruction. A Likert questionnaire was also used. The cadaveric model reproduced CSF circulation in 4 types of dural defects: sellar, suprasellar, transcribriform, and transclival. Intracranial pressures were similar to physiological conditions and were reproducible. Each model was tested multiple times, over several months. Success rates concurred with training levels (r = .8282 and P = .0017). A strong inverse correlation was also found between years of experience and time of reconstruction (r = .4977 and P < .0001). Participants agreed that the model was realistic (median Likert score of 4), and they strongly agreed that it allowed for the improvement of their surgical skills (median Likert score of 5). This novel human-fixed cadaveric model for CSF circulation is efficient and adequately reproduces surgical conditions for skull base approaches. The model is unique, easy to reproduce, and reusable. It can be used as a tool for teaching and for research purposes.