Endoscopic modified Lothrop procedure for repair of lateral frontal sinus cerebrospinal fluid leak

Defining the limits and indications of the Draf III endoscopic approach to the lateral frontal sinus and maximizing visualization and maneuverability: a cadaveric and radiological study

PURPOSE

The DRAF III procedure has been used for access to the lateralmost part of the frontal sinus. We sought to identify anatomical and radiological measurements as well as modifications that predict the lateral limits of visualization and surgical access after this procedure.

METHODS

Seven cadaver heads were imaged with computed tomography scan. The distance from midline to the medial orbital wall (MOWD), midline to the lateral end of the frontal sinus (MLD), the sum of MLDs (SMLD), interorbital distance (IOD) and the shortest anteroposterior distance of the frontal recess (APD) were utilized. The ratios MLD/MOWD, and SMLD/IOD were calculated. The same distances were measured on 41 CT scans. Orbital transposition (OT) and partial resection of the piriform aperture (PAR) were performed; the visualization and reach were assessed. The angle of insertion was measured before and after the modifications.

RESULTS

Only the ratio MLD/MOWD was consistently predictive of access to the lateral, superior and posterior wall of the frontal sinus. Following the modifications, a visualization of 100% laterally was achieved with the 30- and 45 degree endoscopes and every lateral recess could be reached with the 70 degree suction. A mean increase of the angle of insertion of 25.3 and 59.6% was recorded after OT and PAR, respectively.

CONCLUSIONS

IOD rather than APD defines the limits of the Draf III approach to the lateral frontal sinus and MLD/MOWD ratio can serve as a useful preoperative tool. Along to the already described OT, PAR increases visualization and reach of the lateral frontal sinus.

Frontal Sinus Preservation During Cerebrospinal Fluid Leak Repair

BACKGROUND

To validate the repair of frontal sinus cerebrospinal fluid (CSF) leaks with preservation of frontal sinus drainage pathway (FSDP), independently of the approach used, and to establish the indications and limits of the endoscopic approach.

METHODS

A retrospective evaluation of patients undergoing surgery for frontal sinus CSF leaks was performed. Demographics, indications for both endoscopic/combined endoscopic and open approaches, complications, methods for maintaining FSDP, and perioperative outcomes were examined.

RESULTS

Fifty-three patients (average age 45 years) with frontal sinus CSF leaks were treated surgically from 2000 to 2018. All CSF leak repairs were successful at the 1st attempt with a mean follow-up of 76.8 months (range 4-227 months). Etiology was spontaneous (14), traumatic (26), and iatrogenic (13). In 17 patients, a purely endoscopic approach was performed, while an endoscopic endonasal orbital transposition procedure was added in 4 out of this group. In 23 patients, a combined endoscopic and osteoplastic procedure was employed, while in 13 patients a combined craniotomy and endoscopic procedure was performed. All frontal sinuses remained patent except for 2 cranialization patients.

CONCLUSION

With contemporary endoscopic instrumentation and techniques, endoscopic closure of frontal sinus CSF leaks even in the far superolateral wall is feasible in selected patients. However, the surgeon should consider the option of combining an external approach when required. Preserving the FSDP should be the main aim regardless of the approach.

Endoscopic Repairs of Sinonasal Cerebrospinal Leaks: Outcome and Prognostic Factors

OBJECTIVE

The aim of this study was to review the management of sinonasal cerebrospinal fluid (CSF) leaks and outcome of endoscopic repairs and to provide experience regarding leaks at the lateral wall of sphenoid sinus and the posterior wall of frontal sinus.

METHODS

Patients who underwent endoscopic repairs of CSF leaks were reviewed. Characteristics of different etiologies were compared, and prognostic factors were analyzed.

RESULTS

The study included 144 patients with 150 CSF leaks, in which spontaneous leaks account for 55%. Patients with traumatic leaks were significantly younger than those with spontaneous leaks (P = 0.012), and most traumatic leaks occurred in men (P < 0.001). The computed tomography scan showed an overall accuracy of 86.7%. For 17 leaks at the lateral wall of sphenoid sinus, transnasal (29%), transethmoid (24%), and transpterygoid (47%) approaches were used, with a success rate of 75%. For 11 defects at the posterior wall of the frontal sinus, 2 were managed by draf III surgery, and 3 by trephination-assisted procedure successfully. Success rate for primary repair was 95.6%, reaching 100% after a second repairing. Six leaks failed to be repaired included 4 spontaneous leaks, and 3 occurred at the lateral wall of the sphenoid sinus, 4 occurred in patients with elevated body mass index (BMI), 4 had evidence of raised intracranial pressure (ICP).

CONCLUSION

Repair of leaks at lateral sphenoid sinus and posterior frontal sinus could achieve favorable results via selected endoscopic approaches. The failure of repair was associated with inaccessible leak sites, spontaneous leaks, raised ICP, and elevated BMI.

Extended applications of the endoscopic modified Lothrop procedure

OBJECTIVE

The endoscopic modified Lothrop procedure is mainly used for refractory frontal sinusitis. However, we have used it as an access procedure to facilitate treatment for an extended range of additional frontal sinus pathologies.

METHODS

A retrospective review of patients who underwent the endoscopic modified Lothrop procedure for 'alternative' frontal sinus pathologies was conducted. Patient data were reviewed. The main outcome parameter measured was signs of recurrence.

RESULTS

Twelve patients (6 males, 6 females) from a 7-year study period, with a mean age of 45.2 years (range, 16-78 years), were analysed. The surgical indications included frontoethmoidal mucoceles, cerebrospinal fluid leaks within the frontal sinus, cystic fibrosis, frontal sinus osteoma, frontal sinus ossifying fibroma and frontal silent sinus syndrome. The mean follow-up period was 33.3 months. There were no known recurrences.

CONCLUSION

We have used the endoscopic modified Lothrop procedure for a range of frontal sinus pathologies, safely and effectively, with no peri-operative complications.

Endoscopic management of cerebrospinal fluid rhinorrhea

Cerebrospinal fluid (CSF) rhinorrhea occurs due to communication between the intracranial subarachnoid space and the sinonasal mucosa. It could be due to trauma, raised intracranial pressure (ICP), tumors, erosive diseases, and congenital skull defects. Some leaks could be spontaneous without any specific etiology. The potential leak sites include the cribriform plate, ethmoid, sphenoid, and frontal sinus. Glucose estimation, although non-specific, is the most popular and readily available method of diagnosis. Glucose concentration of > 30 mg/dl without any blood contamination strongly suggests presence and the absence of glucose rules out CSF in the fluid. Beta-2 transferrin test confirms the diagnosis. High-resolution computed tomography and magnetic resonance cisternography are complementary to each other and are the investigation of choice. Surgical intervention is indicated, when conservative management fails to prevent risk of meningitis. Endoscopic closure has revolutionized the management of CSF rhinorrhea due to its less morbidity and better closure rate. It is usually best suited for small defects in cribriform plate, sphenoid, and ethmoid sinus. Large defects can be repaired when sufficient experience is acquired. Most frontal sinus leaks, although difficult, can be successfully closed by modified Lothrop procedure. Factors associated with increased recurrences are middle age, obese female, raised ICP, diabetes mellitus, lateral sphenoid leaks, superior and lateral extension in frontal sinus, multiple leaks, and extensive skull base defects. Appropriate treatment for raised ICP, in addition to proper repair, should be done to prevent recurrence. Long follow-up is required before leveling successful repair as recurrences may occur very late.

Cerebrospinal fluid rhinorrhea: evaluation with 3D-SPACE sequence and management with navigation-assisted endonasal endoscopic surgery

BACKGROUND

This study aimed to assess the efficacy of MR images with three-dimensional sampling perfection with application optimised contrast using different flip-angle evolution (3D-SPACE) sequence for detecting cerebrospinal fluid (CSF) rhinorrhea and image-guided surgery for the management of CSF rhinorrhea.

MATERIALS AND METHODS

This study included 45 consecutive patients with suspected CSF rhinorrhea from 2010 to 2015. Patients underwent preoperative MRI scan including 3D-SPACE and conventional T2-weighted (T2W) protocol. Two-blinded neuroradiologists determined the presence and location of CSF leakage. Imaging results were compared with surgical findings and/or β-2 transferrin testing. Intraoperative navigation was used during endonasal endoscopic surgery for repairing CSF rhinorrhea.

RESULTS

3D-SPACE sequence correctly described 27 cases (93.1%) and conventional T2W sequence described only 20 (69.0%) of the total 29 patients with truly positive CSF leakage. The sensitivity, specificity, positive predictive value and negative predictive value for detecting CSF leakages were 93.1%, 87.5%, 93.1%, and 87.5% for 3D-SPACE, and 69.0%, 81.3%, 87.0% and 59.1% for T2W, respectively. To repair the leakage, 3D-SPACE image-guided navigation was used to locate the CSF leakage sites intraoperatively. Only two CSF leakage sites proved by surgery were missed by navigation. Successful endoscopic repairs were achieved in 25 of 26 (96.2%) patients during the first attempt. During the follow-up, there were no major postoperative complications or recurrences encountered.

CONCLUSION

MR imaging with 3D-SPACE sequence is an effective and reliable method with higher sensitivity and specificity than T2W for detecting CSF leakage. Intraoperative 3D-SPACE image-guided navigation is helpful in locating the sites of the CSF leakage during endonasal endoscopic surgery.

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.

State of the art of endoscopic frontal sinus cerebrospinal fluid leak repair

Frontal sinus cerebrospinal fluid leaks are rare and their surgical management is difficult. Up until recently, they could only be treated by open surgery with an osteoplastic flap. With the development of endoscopic surgery, less invasive techniques such as an exclusive endoscopic approach can now be used, ensuring a simpler postoperative course. However, these techniques require a thorough knowledge of frontal sinus anatomy and endoscopic CSF leak repair. This knowledge is essential both to ensure closure of the CSF leak and to preserve frontal sinus patency.

Modified subtotal-Lothrop procedure for extended frontal sinus and anterior skull-base access: a case series

BACKGROUND

The endoscopic modified Lothrop procedure (EMLP) is well established for resistant frontal sinus disease and anterior skull base (ASB) exposure. However, this technique may be unnecessarily aggressive by removing avoidable sinonasal structures in select cases. Previously, in a cadaveric study, we proposed a modification of the EMLP, termed the modified subtotal-Lothrop procedure (MSLP), to access the ASB and to address complex frontal sinus disease, for which access to the bilateral frontal sinus posterior table is required. This study provides a step-by-step description of this technique, and presents our experience in 5 patients who underwent this approach.

METHODS

A retrospective analysis was performed at a tertiary referral center on all patients undergoing endoscopic ASB resection and complex frontal sinus surgeries between May 2011 and May 2013. Of 8 patients identified who underwent an MSLP, 5 had at least 1-year follow-up.

RESULTS

All patients underwent successful ASB exposure via the MSLP without complications and preservation of one frontal sinus recess. Adequate access to the bilateral posterior frontal sinus table was achieved in all cases. A patent frontal sinus drainage pathway could be assessed endoscopically after a mean follow-up of 18.6 (range, 12-27) months.

CONCLUSION

The MSLP is a feasible approach for exposure of the ASB and accessing complex frontal sinus pathology. This modification provides adequate ASB exposure and surgical maneuverability similar to the EMLP, while preserving one frontal sinus recess. This modification was successful in providing adequate exposure and maneuverability as well as maintaining frontal sinus patency in this small cohort.

Modified subtotal lothrop procedure for extended frontal sinus and anterior skull base access: a cadaveric feasibility study with clinical correlates

Objective The endoscopic modified Lothrop procedure (EMLP) is an established approach for recalcitrant frontal sinus disease and anterior skull base exposure. However, in select cases, this technique may involve unnecessary resection of sinonasal structures. In this study, we propose a modification of the EMLP, termed the modified subtotal-Lothrop procedure (MSLP), to access the anterior skull base and complex frontal sinus disease for which access to the bilateral frontal sinus posterior table is required. Methods A cadaveric dissection with photo documentation was performed at an academic medical center on four cadaver heads using standard endoscopic techniques to demonstrate the MSLP and its feasibility. Results The endoscopic MSLP allowed ample access for instrumentation in each of the dissections using a 30- or 70-degree endoscope. Adequate bilateral access to the posterior table of the frontal sinus was gained in all cases without the need for dissection of the contralateral frontal sinus recess (FSR). Conclusion The MSLP appears to be a feasible technique for exposure of the anterior skull base and accessing complex frontal sinus pathology. This modification provides similar anterior skull base exposure and surgical maneuverability as the EMLP while limiting surgical dissection to one FSR, thereby preserving as much of the natural mucociliary drainage pathways as possible.

Endoscopic management of cerebrospinal fluid rhinorrhea: the charing cross experience

Objective To describe our experience of cerebrospinal fluid (CSF) rhinorrhea management. Design Retrospective. Setting Charing Cross Hospital, London, a tertiary referral center. Participants Fifty-four patients with CSF rhinorrhea managed from 2003 to 2011. Main outcome measures Surgical technique; Recurrence. Results Etiologically, 36 were spontaneous and 18 traumatic. Eight patients with spontaneous and two with traumatic leaks had previous failed repairs in other units. Success rates after first and second surgery were 93% and 100%, respectively. Mean follow-up was 21 months. Four patients, all of spontaneous etiology, had recurrences; three of these underwent successful second repair with three layered technique, and the fourth had complete cessation of the leak after gastric bypass surgery and subsequent weight reduction. Adaptation of anatomic three-layered repair since then averted any further failure in the following 7 years. Mean body mass index was 34.0 kg/m(2) in spontaneous and 27.8 kg/m(2) in traumatic cases (p < 0.05). Fifty percent of spontaneous leaks were from the cribriform plate, 22% sphenoid, 14% ethmoid, and 14% frontal sinus. In the traumatic CSF leak group: 33.3% were from the cribriform plate, 33.3% sphenoid, 22.2% ethmoid, and 11.1% frontal. Conclusion Endoscopic CSF fistula closure is a safe and effective operation. All sites of leak can be accessed endoscopically. We recommend the use of an anatomic three-layered closure in difficult cases.

Modified hemi-Lothrop procedure for supraorbital frontal sinus access: a cadaveric feasibility study

OBJECTIVE

The endoscopic modified Lothrop procedure (EMLP) is a relatively safe and efficacious advanced approach to access the frontal sinus for recalcitrant disease. There have been limited data specifically addressing those patients with advanced but unilaterally limited and supraorbitally based frontal sinus disease. In this study, the authors propose a modification of the EMLP technique, titled a modified hemi-Lothrop procedure (MHLP), which would limit the dissection of the EMLP to removal of the frontal sinus floor of the unilaterally diseased frontal sinus, thereby sparing the mucosa and natural drainage pathways of the nondiseased contralateral frontal sinus.

STUDY DESIGN AND SETTING

Cadaveric study at an academic medical center.

METHODS

A cadaveric dissection with photodocumentation was performed to demonstrate the MHLP and to quantify the accessibility of this approach to far-laterally based frontal sinus disease.

RESULTS

The MHLP dissection was shown to provide adequate access to the most distal supraorbital and laterally based aspects of the frontal sinus. Using 3 cadavers, the authors demonstrated and documented the technique of MHLP to access lateral frontal sinus disease from the contralateral nasal cavity via a superior septectomy window.

CONCLUSION

The MHLP was demonstrated to be a feasible approach and alternative to more traditional endoscopic procedures in addressing unilateral frontal sinus disease. This modification may be useful in addressing difficult to access unilateral disease that may otherwise require more extensive resection. This demonstration helps define the accessibility of the lateral frontal sinus via an MHLP and begins to provide estimates of which patients may benefit from this approach.