Endoscopic endonasal suturing of dural reconstruction grafts: a novel application of the U-Clip technology. Technical note

Kashimé: A Novel Knotless Surgical Suture to Simplify Dural Stitches in Endoscopic Transnasal Surgery

BACKGROUND

Dural suturing is an effective adjunct to skull base dural repair in endoscopic transnasal surgery, although it is technically cumbersome. Here, we presented a novel surgical suture "Kashimé" (Kono Seisakusho) that can be tightened without tying.

OBJECTIVE

To examine the efficacy of Kashimé for skull base dural repair in endoscopic transnasal surgery.

METHODS

Kashimé was used in 8 patients with skull base dural defects during nonpedicled flap-based multilayered skull base reconstruction to close or approximate the gaps between the dural edges or secure a free fascial graft. The time required for each dural stitch (passing a needle through the dura, pulling out the thread, and tightening it) and the incidence of postoperative cerebrospinal fluid leakage were the study end points.

RESULTS

Based on our preliminary experiences with 12 stitches used, no postoperative cerebrospinal fluid leakage was observed. The learning curve was steep, and the mean (±SD) time was 127 (±44) seconds for a single stitching procedure, except for the first case. Regarding the metal artifact, although a beam hardening artifact was not observed on computed tomography, a 4- to 9-mm diameter image defect was observed on magnetic resonance imaging.

CONCLUSION

Kashimé can help surgeons to complete a single dural stitch in endoscopic transnasal surgery for approximately 2 minutes. It may be an optimal tool for skull base reconstruction, but the efficacy and safety need to be investigated.

Endoscopic endonasal resection of sinonasal teratocarcinosarcoma with intracranial breakthrough: illustrative case

BACKGROUND

Teratocarcinosarcoma traversing the anterior skull base is rarely reported in literature. The heterogenous and invasive features of the tumor pose challenges for surgical planning. With technological advancements, the endoscopic endonasal approach (EEA) has been emerging as a workhorse of anterior skull base lesions. To date, no case has been reported of EEA totally removing teratocarcinosarcomas with intracranial extensions.

OBSERVATIONS

The authors provided an illustrative case of a 50-year-old otherwise healthy man who presented with left-sided epistaxis for a year. Imaging studies revealed a 31 × 60-mm communicating lesion of the anterior skull base. Gross total resection via EEA was achieved, and multilayered skull base reconstruction was performed.

LESSONS

The endoscopic approach may be safe and effective for resection of extensive teratocarcinosarcoma of the anterior skull base. To minimize the risk of postoperative cerebrospinal fluid leaks, multilayered skull base reconstruction and placement of lumbar drainage are vitally important.

Multi-Layer Onlay Graft Using Hydroxyapatite Cement Placement without Cerebrospinal Fluid Diversion for Endoscopic Skull Base Reconstruction

Objective

The skull base reconstruction step, which prevents cerebrospinal fluid (CSF) leakage, is one of the most challenging steps in endoscopic skull base surgery (ESS). The purpose of this study was to assess the outcomes and complications of a reconstruction technique for immediate CSF leakage repair using multiple onlay grafts following ESS.

Methods

A total of 230 consecutive patients who underwent skull base reconstruction using multiple onlay grafts with fibrin sealant patch (FSP), hydroxyapatite cement (HAC), and pedicled nasoseptal flap (PNF) for high-flow CSF leakage following ESS at three institutions were enrolled. We retrospectively reviewed the medical and radiological records to analyze the preoperative features and postoperative results.

Results

The diagnoses included craniopharyngioma (46.8%), meningioma (34.0%), pituitary adenoma (5.3%), chordoma (1.6%), Rathke’s cleft cyst (1.1%) and others (n=21, 11.2%). The trans-planum/tuberculum approach (94.3%) was the most commonly adapted surgical method, followed by the trans-sellar and transclival approaches. The third ventricle was opened in 78 patients (41.5%). Lumbar CSF drainage was not performed postoperatively in any of the patients. Postoperative CSF leakage occurred in four patients (1.7%) due to technical mistakes and were repaired with the same technique. However, postoperative meningitis occurred in 13.5% (n=31) of the patients, but no microorganisms were identified. The median latency to the diagnosis of meningitis was 8 days (range, 2–38). CSF leakage was the unique risk factor for postoperative meningitis (p<0.001).

Conclusion

The use of multiple onlay grafts with FSP, HAC, and PNF is a reliable reconstruction technique that provides immediate and complete CSF leakage repair and mucosal grafting on the skull base without the need to harvest autologous tissue or perform postoperative CSF diversion. However, postoperative meningitis should be monitored carefully.

The Rostral Mucosa: The Door to Open and Close for Targeted Endoscopic Endonasal Approaches to the Clivus

BACKGROUND

Extended endoscopic endonasal approaches (EEAs) have progressively widened the armamentarium of skull base surgeons. In order to reduce approach-related morbidity of EEAs and closure techniques, the development of alternative strategies that minimize the resection of normal tissue and alleviate the use of naso-septal flap (NSF) is needed. We report on a novel targeted approach to the clivus, with incision and closure of the mucosa of the rostrum, as the initial and final step of the approach.

OBJECTIVE

To present an alternative minimally invasive approach and reconstruction technique for selected clival chordomas.

METHODS

Three cases of clival chordomas illustrating this technique are provided, together with an operative video.

RESULTS

The mucosa of the rostrum is incised and elevated from the underlying bone, as first step of surgery. Following tumor resection with angled scope and instruments, the mucosa of the sphenoid sinus (SS) is removed and the tumor cavity and SS are filled with abdominal fat. The mucosal incision of the rostrum is then sutured. A hangman knot is prepared outside the nasal cavity and tightened after the first stitch and a running suture is performed.

CONCLUSION

We propose, in this preliminary report, a new targeted approach and reconstruction strategy, applying to EEAs the classic concept of skin incision and closure for transcranial approaches. With further development in the instrumentations and visualization tools, this technique may become a valuable minimally invasive endonasal approach for selected lesions.

Traumatic Nonmissile Penetrating Transnasal Anterior Skull Base Fracture and Brain Injury with Cerebrospinal Fluid Leak: Intraoperative Leak Detection and an Effective Reconstruction Procedure for a Localized Skull Base Defect Especially After Coronavirus Disease 2019 Outbreak

Background

Cerebrospinal fluid (CSF) leakage after penetrating skull base injury is relatively rare compared with close head injuries involving skull base fractures.

Case Description

We report the case of a 65-year-old man who had presented with epistaxis and serous rhinorrhea. When he had fallen to the ground near his bee boxes, a garden pole had poked into his right nostril. He had instantly removed the pole from his nostril himself. However, immediately after removal of the pole, he had developed nasal bleeding and serous rhinorrhea. He then drove to our emergency room. Computed tomography showed pneumocephalus with a minor cerebral contusion in the left frontal lobe and a penetrating injury in the left anterior skull base. His CSF leakage had not resolve spontaneously within 1 week after the injury with strict bed rest. We repaired the CSF leakage using a fat (adipose tissue)-on-fascia autograft plug and caulked the defect in the anterior skull base with the fat-on-fascia graft (FFG) plug through the left nostril with endoscopic guidance. The CSF rhinorrhea was successfully controlled. Intranasal local application of fluorescein aided in the detection of the direction of flow of the CSF leakage.

Conclusions

Endonasal endoscopic caulking of a skull base defect using an FFG plug can be useful to treat CSF leakage due to the localized skull base defect, especially in the coronavirus disease 2019 pandemic. It is simple, inexpensive, and timesaving. It requires no special skills nor sophisticated instruments that can cause aerosolization, reducing the risk of infection during the surgery.

The sellar barrier and intraoperative CSF leak in elderly patients

Cerebral spinal fluid (CSF) leak is a significant complication in pituitary surgery, increasing both patient morbidity and mortality. In a recent publication, Campero et al. observed worse postoperative prognosis and increased risk of intraoperative CSF leak in patients with reduced sellar barrier thickness. The objective of this study was to analyze the association between sellar barrier thickness and intraoperative CSF leak in older individuals. A retrospective review was conducted of 44 transsphenoidal surgery resections for pituitary adenomas, 24 microscopic and 20 purely endoscopic procedures. Presence of intraoperative CSF fistula was significantly greater in patients with weak sellar barrier (thickness under 1 mm), compared to strong sellar barrier (52.94% vs 3.70% p < 0.0001, respectively). Application of this novel concept may help improve surgical technique selection as well as predict risk of intraoperative CSF leak and need for eventual use of flaps for reconstruction.

Usefulness of the knot-tightener device following dural suturing in endonasal transsphenoidal surgery: technical report

Transsphenoidal surgery (TSS) has become a well-established standard surgical technique, but the cerebrospinal fluid leakage remains controversial. Direct suturing of the dura, which is a routine procedure within transcranial surgery, can be applied for closure of the sella turcica within TSS. However, as the dura is not accessible by the index finger, knot tying in the narrow and deep surgical corridor following dural suturing is extremely difficult, cumbersome, and time-consuming in TSS. Here, we present a new, simple, and effective technique for knot tying using our newly developed instrument the "knot tightener" (UC-6603: Medical U & A, Inc., Osaka, Japan) to solve this challenge. The knot tightener has a total length of 235 mm and is bayonet shaped. The tip is 5 × 10 mm in diameter and has one long arm and two short curved arms. The long arm has a dimple which can hook and hold a thread, fulfilling the role of an index finger. Together the two short curved arms make a half circle and are able to hook a thread easily. From the 28th of March 2011 to August 2018, we used the knot-tightener device for 566 patients who underwent endonasal TSS, to deliver and tie knots following stitching of the dura using 6-0 nylon. The device was able to easily deliver a knot from outside of the nostril to the sella turcica through the nasal cavity and successfully tighten it firmly. No complications were observed, confirming the safety of the newly designed instrument. The knot tightener can be considered to be an optimal tool for the challenging surgical procedure of knot tying following dural suturing in TSS. Its potential future applications may extend to include other neurosurgical procedures in anatomically restricted areas.

A low cost and stepwise training model for skull base repair using a suturing and knotting technique during endoscopic endonasal surgery

PURPOSE

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.

METHODS

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.

RESULTS

Group A finishes the first and second tasks in significantly less time (total time, 125.1 ± 10.8 vs 195.8 ± 15.9 min) 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.

CONCLUSIONS

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.

Endoscopic endonasal resection of the odontoid process: clinical outcomes in 34 adults

OBJECTIVE Treatment of odontoid disease from a ventral corridor has consisted of a transoral approach. More recently, the endoscopic endonasal approach (EEA) has been used to access odontoid pathology. METHODS A retrospective review was conducted of patients who underwent an EEA for odontoid pathology from 2004 to 2013. During our analysis, the mean follow-up duration was 42.6 months (range 1-80 months). Patient outcomes, complications, and postoperative swallowing function were assessed either by clinic visit or phone contact. RESULTS Thirty-four patients underwent an EEA for symptomatic odontoid pathology. The most common pathology treated was basilar invagination (n = 17). Other pathologies included odontoid fractures, os odontoideum, and metastatic carcinoma. The mean patient age was 71.5 years. Thirty-one patients underwent a posterior fusion. All 34 patients experienced stability or improvement in symptoms and all had successful radiographic decompression. The overall complication rate was 76%. Nearly all of these complications were transient (86%) and the overall complication rate excluding mild transient dysphagia was only 44%. Twenty-one patients (62%) suffered from transient postoperative dysphagia: 15 cases were mild, transient subjective dysphagia (6 of whom had documented preoperative dysphagia), whereas 6 other patients required tube feedings for decreased oral intake, malnutrition, and dysphagia in the perioperative setting (5 of these patients had documented preoperative dysphagia). Sixteen patients had documented preoperative dysphagia and 6 of these had lower cranial nerve dysfunction. Postoperatively, 6 (37.5%) of 16 patients with preoperative dysphagia and 4 (67%) of 6 with lower cranial nerve dysfunction had significant dysphagia/respiratory complications. Eighteen patients had no documented preoperative dysphagia and only 2 had significant postoperative dysphagia/respiratory complications (11%). The rates of these complications in patients without preoperative dysphagia were lower than in those with any preoperative dysphagia (p = 0.07) and especially those with preexisting lower cranial neuropathies (p = 0.007). Dysphagia was also significantly more common in patients who underwent occipitocervical fixation (19/26, 73%) than in patients who underwent cervical fusion alone or no fusion (2/8, 25%; p = 0.02). All patients with perioperative dysphagia had improved at follow-up and all patients were tolerating oral diets. No patient suffered from velopalatal insufficiency. Two patients had intraoperative CSF leaks. One of these patients underwent a negative exploratory surgery for a questionable postoperative CSF leak. One patient developed infection in the resection bed requiring debridement and antibiotics. One patient died 8 days following surgery from an unknown cause. The 90-day perioperative mortality rate was 2.9%. CONCLUSIONS A completely EEA can be performed for compressive odontoid disease in all cases of neoplastic, degenerative, or invaginative atlantoaxial disease with satisfactory outcomes and low morbidity. Transient perioperative dysphagia and respiratory complications are common, usually as an exacerbation and reflection of underlying disease or occipitocervical fusion rather than the EEA, emphasizing the importance of avoiding transoral surgery.

A simple classification of cranial-nasal-orbital communicating tumors that facilitate choice of surgical approaches: analysis of a series of 32 cases

Cranial–nasal–orbital communicating tumors involving the anterior and middle skull base are among the most challenging to treat surgically, with high rates of incomplete resection and surgical complications. Currently, there is no recognized classification of tumors with regard to the choice of surgical approaches. From January 2004 to January 2014, we classified 32 cranial–nasal–orbital communicating tumors treated in our center into three types according to the tumor body location, scope of extension and direction of invasion: lateral (type I), central (type II) and extensive (type III). This classification considerably facilitated the choice of surgical routes and significantly influenced the surgical time and amount of hemorrhage during operation. In addition, we emphasized the use of transnasal endoscopy for large and extensive tumors, individualized treatment strategies drafted by a group of multidisciplinary collaborators, and careful reconstruction of the skull base defects. Our treatment strategies achieved good surgical outcomes, with a high ratio of total resection (87.5 %, 28/32, including 16 cases of benign tumors and 12 cases of malignant tumors) and a low percentage of surgical complications (18.8 %, 6/32). Original symptoms were alleviated in 29 patients. The average KPS score improved from 81.25 % preoperatively to 91.25 % at 3 months after surgery. No serious perioperative complications occurred. During the follow-up of 3 years on average, four patients with malignant tumors died, including three who had subtotal resections. The 3-year survival rate of patients with malignant tumors was 78.6 %, and the overall 3-year survival rate was 87.5 %. Our data indicate that the simple classification method has practical significance in guiding the choice of surgical approaches for cranial–nasal–orbital communicating tumors and may be extended to other types of skull base tumors.

A new multilayer reconstruction using nasal septal flap combined with fascia graft dural suturing for high-flow cerebrospinal fluid leak after endoscopic endonasal surgery

This study aimed to evaluate the usefulness and reliability of a new endoscopic multilayer reconstruction using nasal septal flap (NSF) to prevent high-flow cerebrospinal fluid leak after endoscopic endonasal surgery. This study was a retrospective review on 97 patients who underwent multilayer reconstructions using NSF combined with fascia graft dural suturing after endoscopic endonasal surgery between July 2012 and March 2014. Patients were divided into two groups, third ventricle opening group and nonopening group, based on the presence of a direct connection between the third ventricle and the paranasal sinus after tumor removal. Furthermore, we compared this procedure with our previous reconstruction after resection of craniopharyngioma. Finally, we checked the patients who had postoperative prolonged discomfort of the nasal cavity for over a year. Postoperative cerebrospinal fluid (CSF) leak occurred in three patients (3.1 %): one from the third ventricle opening group and the remaining two from the nonopening group. External lumbar drain was performed after surgery in only seven patients (7.2 %). The incidence of postoperative CSF leak was similar in both groups, whereas the rate of craniopharyngioma in the third ventricle opening group was significantly higher. The incidence of postoperative CSF leak after resection of craniopharyngioma was not statistically significant but obviously higher in the previous group (12.2 %) compared with that in the present group (2.3 %). Twelve patients (12.4 %) had postoperative nasal discomfort of the nasal cavity for over a year. Multilayer reconstruction using NSF combined with fascia graft dural suturing is a more reliable method for preventing postoperative high-flow CSF leakage after endoscopic endonasal surgery even if there is a direct connection between the third ventricle and the paranasal sinus. However, we should pay close attention especially to prolonged discomfort of the nasal cavity after harvesting NSF.

Banked Fascia Lata in Sellar Dura Reconstruction after Endoscopic Transsphenoidal Skull Base Surgery

Objectives Cerebrospinal fluid (CSF) leakage is an undesirable complication of transsphenoidal skull base surgery. The issue of the most appropriate sellar dura repair remains unresolved, although a multilayer technique using autologous fascia lata is widely used. We describe the novel application of a homologous banked fascia lata graft as an alternative to an autologous one in the reconstruction of sellar dura defects in endoscopic transsphenoidal surgery. Design The clinical records of patients who underwent endoscopic transsphenoidal surgery at our department from June 2012, when we started using homologous fascia lata, up to July 2014 were reviewed retrospectively. The data concerning diagnosis, reconstruction technique, and surgical outcome were analyzed. Results We treated 16 patients successfully with banked fascia lata. Twelve patients presented intraoperative CSF leakage, and four patients were treated for postoperative rhinoliquorrhea. Banked fascia lata was used in a single-to-multilayer technique, depending on the anatomical features of the defect and of the sellar floor. No complications or failures in sella reconstruction occurred. Conclusion A banked fascia lata graft proved reliable and safe in providing an effective sellar dura reconstruction. Used in a multilayer strategy, it should be considered a viable alternative to an autologous fascia lata graft.

Early and late complications of endoscopic hemostatic techniques following different carotid artery injury characteristics

BACKGROUND

The most dreaded hemorrhagic complication in endoscopic endonasal surgery is injury to the internal carotid artery (ICA). Although a number of treatment protocols are currently used, none have been formally investigated. This study aims to compare the efficacy of the muscle patch, bipolar diathermy, and aneurysm clip on hemostasis, pseudoaneurysm formation, and long-term vessel patency for different injury types in a sheep model of carotid bleeding.

METHODS

Twenty-seven sheep underwent ICA dissection/isolation followed by the artery placement within a modified "sinus model otorhino neuro trainer" (SIMONT) model. Standardized linear, punch, and stellate injuries were made. Randomization of sheep to receive 1 of 3 hemostatic techniques was performed (muscle, bipolar, clip). Specific outcome measures included attainment of primary hemostasis, time to hemostasis, blood loss, pseudoaneurysm formation, and carotid patency on follow-up magnetic resonance imaging (MRI).

RESULTS

Bipolar achieved primary hemostasis in 7 of 9 cases and 2 cases of secondary hemorrhage. It had no associated pseudoaneurysm formation. Carotid patency was variable on follow-up MRI. Muscle patch achieved 100% primary hemostasis with 2 cases of secondary hemorrhage. There were 2 cases of pseudoaneurysm and 100% patency rate on follow-up MRI. Aneurysm clip achieved 100% primary hemostasis with 1 case of secondary hemorrhage. No pseudoaneurysm formation and a 50% rate of carotid insufficiency on MRI.

CONCLUSION

This study shows that the crushed muscle patch and aneurysm clip can be viable options in the management of ICA injury with short-term and long-term benefits. Complications associated with these techniques were comparable if not reduced when compared to the published literature.

Surgical nuances for the endoscopic endonasal transpterygoid approach to lateral sphenoid sinus encephaloceles

Lateral sphenoid encephaloceles of the Sternberg canal are rare entities and usually present with spontaneous CSF rhinorrhea. Traditionally, these were treated via transcranial approaches, which can be challenging given the deep location of these lesions. However, with advancements in endoscopic skull base surgery, including improved surgical exposures, angled endoscopes and instruments, and novel repair techniques, these encephaloceles can be resected and successfully repaired with purely endoscopic endonasal approaches. In this report, the authors review the endoscopic endonasal transpterygoid approach to the lateral recess of the sphenoid sinus for repair of temporal lobe encephaloceles, including an overview of the surgical anatomy from an endoscopic perspective, and describe the technical operative nuances and surgical pearls for these cases. The authors also present 4 new cases of lateral sphenoid recess encephaloceles that were successfully treated using this approach.

Challenges and surgical nuances in reconstruction of large planum sphenoidale tuberculum sellae defects after endoscopic endonasal resection of parasellar skull base tumors

OBJECTIVES/HYPOTHESIS

Endoscopic endonasal transplanum transtuberculum (EETT) resection of parasellar skull base (SB) tumors often results in large SB defects with intraoperative high-flow cerebrospinal fluid (CSF) leaks. Reconstruction of these defects can be challenging because of the large defects size, communication with the suprasellar cistern, and close proximity to the optic nerves and chiasm. Recent studies have postulated that transplanum defects may be associated with increased postoperative CSF leakage. We review our experience with reconstruction of transplanum defects after EETT resection of parasellar SB tumors. Challenges encountered during these repairs and our operative nuances for successful reconstruction are discussed.

METHODS

A retrospective analysis was performed between March 2010 and February 2012 on patients undergoing reconstruction of transplanum defects after EETT resection of parasellar SB tumors. Repair materials, defect sizes, postoperative CSF leakage, postoperative CSF diversion, and demographic data were collected.

RESULTS

Nineteen patients who underwent 22 repairs with a pedicled nasoseptal flap (PNSF) were identified. The mean age was 47.6 years (range, 12-68 years). Average defect size was 5.6 cm(2) (range, 2.2-10.4 cm(2)). Three failed repairs necessitated a revision procedure. All three revisions were successfully reconstructed with the previously used PNSF. The mean follow-up period was 13.5 months (range, 1-26 months). The overall success rate was 86.4% for transplanum defects alone, as compared to 97.0% for our comprehensive PNSF experience in 99 repairs.

CONCLUSION

Repair of large transplanum defects after EETT resection of parasellar SB tumors presents a unique challenge. Using a PNSF along with meticulous multilayer closure may help decrease postoperative CSF leaks.

Barrier-limited multimodality closure for reconstruction of wide sellar openings

BACKGROUND

Obtaining a watertight reconstruction with a fat graft with wide sellar exposures can be challenging, including the risk of reinstating mass effect with the fat graft. The alternative, a vascularized pedicle nasoseptal flap, may require several days to heal and still has a > 5% cerebrospinal fluid (CSF) leak rate.

OBJECTIVE

To assess the efficacy of a barrier-limited multimodality (BLMM) closure, consisting of an autograft fat-based watertight seal and limited by a membrane barrier, together with the vascularized nasoseptal flap.

METHODS

This is a retrospective review of 27 consecutive patients undergoing endonasal cranial base surgery limited to the sellar-parasellar region at the UCLA Medical Center who experienced an intraoperative CSF leak that was repaired with the BLMM technique. The results of 43 prior case-controlled reconstructions using a nasoseptal flap, without the full BLMM technique, were analyzed as a comparison group.

RESULTS

There were no postoperative CSF leaks in the patients reconstructed with the BLMM closure technique. The CSF leak rate for the comparison group receiving nasoseptal flaps was 19%.

CONCLUSION

A BLMM closure may further decrease the incidence of postoperative CSF leaks compared with predominant reliance on a nasoseptal flap. The novel membrane barrier allows a watertight inner closure by preventing herniation of the fat autograft into the resection cavity. An outer-layer nasoseptal flap provides a living barrier for optimal long-term defense.

Primary closure of a cerebrospinal fluid fistula by nonpenetrating titanium clips in endoscopic endonasal transsphenoidal surgery: technical note

Postoperative cerebrospinal fluid (CSF) leakage is one of the most common and aggravating complications in transsphenoidal surgery. Although primary closure of the fistula would be the most desirable solution for an intraoperatively encountered CSF leak, it is difficult to achieve in such a deep and narrow operative field. In this article, the authors report endonasal endoscopic applications of no-penetrating titanium clips to repair a CSF fistula following tumor removal. The AnastoClip Vessel Closure System (VCS; LeMaitre Vascular, Boston, MA) was used for closure of a CSF fistula in endonasal transsphenoidal surgery. In all four patients, CSF leakage was successfully obliterated primarily with two to five clips. There was no postoperative CSF rhinorrhea or complications related to the use of the VCS. Metal artifact by the clips on postoperative images was tolerable. Primary closure of the fistula using the VCS was an effective strategy to prevent postoperative CSF leakage in transsphenoidal surgery. Future application can be expanded to reconstruction of the skull base dura via endonasal skull base approaches.

Feasibility of a robotic surgical approach to reconstruct the skull base

The role of robotic surgery in the skull base is evolving and represents the natural progression toward maximizing surgical resections in confined spaces without compromising oncological principles. In this study, we describe the novel application of robotic surgery to the repair of dural defects in the skull base. A transmaxillary-transantral approach to the nasal cavity was performed bilaterally in a cadaveric model. Repair of the skull base defect was undertaken robotically. In this technical report, we demonstrate the feasibility of a suture-based technique for surgical reconstruction of the skull base with robotic assistance in a cadaveric model. In all cases, suture repair of dural defects was successfully performed with robotic-assisted technique. Although preliminary in nature, this study suggests that traditional suture techniques can be implemented in a confined surgical site with the use of robotic technology.

Efficacy of the pedicled nasoseptal flap without cerebrospinal fluid (CSF) diversion for repair of skull base defects: incidence of postoperative CSF leaks

BACKGROUND

The advances in endoscopic skull base surgery have led to the resection of increasingly larger cranial base lesions and the creation of larger skull base defects with the potential for increased postoperative high-flow cerebrospinal fluid (CSF) leaks. These concerns led to the development of the vascularized pedicled nasoseptal flap (PNSF), which is now used as the mainstay for repair of large skull base defects in many academic centers. In this report, we review the incidence of postoperative CSF leaks in our institution in patients undergoing endoscopic skull base repair of high-flow CSF leaks with a vascularized PNSF without concurrent CSF diversion.

METHODS

We performed a retrospective analysis at our tertiary care medical center on patients who underwent endoscopic repair of high-flow CSF leaks using a PNSF without CSF diversion between July 2008 and August 2011. Repair materials, incidence of postoperative CSF leaks, and demographic data were collected.

RESULTS

Fifty-nine high-flow CSF leaks were repaired with a PNSF and other repair materials, without the use of lumbar catheter drainage. No postoperative CSF leak occurred in this cohort of patients. The overall postoperative CSF leak rate was 0%.

CONCLUSION

Meticulous multilayer-closure of skull base defects is critical to prevent postoperative CSF leaks. Although lumbar drainage may be useful in select scenarios, it carries inherent risks of intracranial hypotension and pneumocephalus, and may not be necessary for routine management of high-flow CSF leaks in conjunction with a robust PNSF. Further prospective randomized controlled studies may be warranted to evaluate the efficacy of postoperative lumbar drainage.

Nasoseptal flap repair after endoscopic transsellar versus expanded endonasal approaches: is there an increased risk of postoperative cerebrospinal fluid leak?

OBJECTIVES/HYPOTHESIS

The development of expanded endoscopic endonasal approaches (EEAs) has allowed resection of cranial-base lesions beyond the sella. One major criticism is an increased risk of postoperative cerebrospinal fluid (CSF) leakage because of the larger skull base defect. We evaluated our experience with vascularized pedicled nasoseptal flap (PNSF) reconstruction and compared the postoperative CSF leak rates between patients undergoing endoscopic transsphenoidal (transsellar) approaches versus expanded EEA (transplanum-transtuberculum, transcribriform, transclival).

STUDY DESIGN

Retrospective analysis at a tertiary care medical center.

METHODS

A retrospective review of a prospective database was performed on patients who underwent PNSF reconstruction for intraoperative high-flow CSF leaks after EEA between December 2008 and August 2011. Demographic data, repair materials, surgical approach, and incidence of postoperative CSF leaks were collected.

RESULTS

Thirty-seven transsellar defects (group I) were repaired with a PNSF, and 32 expanded EEA defects (19 transplanum-transtuberculum, 10 transcribriform, three transclival) (group II) were repaired with a PNSF. No postoperative CSF leaks occurred in group I. One delayed postoperative CSF leak was encountered in group II leading to a 3.1% leak rate in that group. The incidence of postoperative CSF leakage was not significantly different between the two groups (P > .05). Our overall success rate in this series using a PNSF was 98.6%.

CONCLUSIONS

Based on our data, there is no significant increased risk of postoperative CSF leak between transsellar and expanded EEA defects when a PNSF is used. The potential risk of postoperative CSF leaks associated with larger defects created through expanded EEA can be minimized by multilayered closure with a PNSF and meticulous surgical technique.

Primary closure of inadvertent durotomies utilizing the U-Clip in minimally invasive spinal surgery

STUDY DESIGN

Retrospective clinical cohort study.

OBJECTIVE

To examine performance of the U-Clip for the closure of inadvertent durotomy occurring during minimally invasive spinal surgery.

SUMMARY OF BACKGROUND DATA

Primary closure of inadvertent durotomies that occur during minimally invasive spinal surgery can be technically difficult to accomplish when using standard knot-tying and suture management techniques, owing to the narrow and deep surgical corridor afforded by tubular retraction systems. The U-Clip is a novel device that can achieve tight tissue approximation without the need for knot-tying and excessive suture manipulation, making it ideally suited for use in minimally invasive spinal surgeries.

METHODS

We performed a retrospective review of patients who underwent minimally invasive decompressive procedures complicated by durotomy and repaired using U-Clips for the period January 2008 to January 2010. A total of seven patients were identified.

RESULTS

Four of the seven patients were male. Six patients underwent lumbar laminectomy or discectomy. One patient underwent resection of a cervical synovial cyst. In each patient, the durotomy was repaired primarily using U-Clips. All six lumbar patients were discharged home on the same day, and the remaining patient was discharged the following morning. Mean follow-up was 6.3 months. No patient experienced symptoms related to persistent cerebrospinal fluid leakage.

CONCLUSION

Primary closure of an inadvertent durotomy occurring during minimally invasive spinal surgery can be effectively achieved using the self-closing U-Clip device.

High anterior cervical approach to the clivus and foramen magnum: a microsurgical anatomy study

BACKGROUND

Surgical exposure of lesions located along the ventral foramen magnum (FM) and clivus poses a unique set of challenges to neurosurgeons. Several approaches have been developed to access these regions with varying degrees of exposure and approach-related morbidity.

OBJECTIVE

To describe the microsurgical anatomy of the high anterior cervical approach to the clivus and foramen magnum, and describe novel skull base extensions of the approach.

METHODS

Eight adult cadaveric specimens were included in this study. The high anterior cervical approach includes a minimal anterior clivectomy and its lateral skull base extensions: the extended anterior far-lateral clivectomy and the inferior petrosectomy. The microsurgical anatomy and exposure of the various extensions of the approach were analyzed. In addition, the capability of complementary endoscopy was evaluated.

RESULTS

With proper positioning, the minimal anterior clivectomy exposed the vertebrobasilar junction, proximal basilar artery, anteroinferior cerebellar arteries, and 6th cranial nerve. The lateral skull base extensions provided access to the anterior FM, mid-lower clivus, and petroclival region, up to the Meckel cave, contralateral to the side of the surgical approach.

CONCLUSION

The high anterior cervical approach with skull base extensions is an alternative to the classic approaches to the ventral FM and mid-lower clivus. A minimal anterior clivectomy provides access to the midline mid-lower clivus. The addition of an extended anterior far-lateral clivectomy and an inferior petrosectomy extends the exposure to the anterior FM and cerebellopontine angle lying anterior to the cranial nerves. The approach is also ideally suited for endoscopic-assisted techniques.

Circumferential watertight dural repair using nitinol U-clips in expanded endonasal and sublabial approaches to the cranial base

BACKGROUND

In recent years, significant advances have been made in the field of expanded endonasal approaches that permit treatment of different cranial base intradural lesions.

OBJECTIVE

To report our technique of cranial base dural repair by the application of nitinol U-Clips in endoscope-assisted extended endonasal or sublabial approaches. Closure techniques and postoperative cerebrospinal (CSF) leaks are reported.

METHODS

We reviewed 11 patients with different kinds of cranial base tumors or vascular diseases (2 tuberculum sellae meningiomas, 1 planum sphenoidale meningioma, 4 craniopharyngiomas, 1 recurrent clival chordoma, 1 esthesioneuroblastoma, 1 ethmoidal melanoma metastasis, 1 basilar trunk aneurysm) who underwent an endoscope-assisted extended endonasal or sublabial approach. Dural repair was performed using nitinol U-Clips to circumferentially suture AlloDerm or fascia lata directly to the existing dural borders. Lumbar drainage was not used in 9 patients and was used in 2 patients for 5 days. Patients were evaluated for the appearance of CSF leaks.

RESULTS

Postoperative CSF leak was observed in 1 patient (9%). This required a second transnasal repair.

CONCLUSION

Circumferential dural closure with U-Clips is a useful adjunct to prevent CSF leaks after expanded endonasal or sublabial approaches to the cranial base for treatment of intracranial pathology.

U-clip for airway reconstruction: an experimental study of the feasibility of a robot-assisted endoscopic procedure

BACKGROUND

The U-clip anastomotic device was developed to facilitate interrupted anastomoses without the need to tie sutures. Recently, this technology has been expanded into various fields of surgery. However, in the field of airway reconstruction, there have been no previous reports of this technology being used. The present study examined the technical feasibility of performing safe and efficient robot-assisted endoscopic airway reconstruction using nitinol U-clips in rabbits.

METHODS

A total of six tracheal anastomoses with S60 U-clips were performed using the da Vinci Surgical System. Anastomosis time and complications were recorded. The effectiveness of anastomoses was evaluated by postoperative observation of rabbits for 8 weeks and measurement of anastomotic strictures and pathological findings.

RESULTS

All procedures were completed safely. Mean procedure time was 14 ± 1.8 min (mean ± SD). There were no perioperative complications; however, all animals died between postoperative days 14-27, and anastomotic stricture was the likely cause of death. All anastomoses had severe strictures; the mean stricture rate was measured as being 51.1 ± 33.3 (%).

CONCLUSIONS

Although the technical feasibility of robot-assisted endoscopic airway reconstruction using U-clips has been demonstrated in rabbits, the safety of this technique has not been evaluated. Our data suggest that U-clips are not a feasible approach for airway reconstruction surgery because of the occurrence of severe postoperative anastomotic stricture.

Comparison of endoscopic transnasal and transoral approaches to the craniovertebral junction

OBJECTIVE

The study compared the endoscopic anatomy of the transnasal and transoral approaches to the craniovertebral junction (CVJ).

METHODS

Structures examined and compared with both the straight and angled telescopes in 10 cadaveric specimens included the pharyngeal walls and adjacent musculature, resected anterior arch of the axis and odontoid, cruciform, axial, and apical ligaments, clival and dural openings, and the intradural exposure.

RESULTS

There is considerable overlap at the pharyngeal level in the structures that can be viewed by the transoral and transnasal routes. The transoral approach provides a wider corridor with less restricted manipulation of instruments than the transnasal approach, but the transnasal approach provides a better view of the clivus, upper part of the CVJ, and the structures posterior to the removed odontoid and anterior arch of C1. Combining the two approaches provides significantly better access to the midline anterior CVJ than either approach alone, allows the scopes to be advanced in one cavity and the surgical instruments in the other cavity, and reduces the need to split the palate, tongue, or mandible in order to reach the target area. The transnasal approach also allows access to the superior part of the occipital condyles, paraclival areas, and hypoglossal canals without removal of the condyles, but these structures can be exposed by the transoral route only after at least partial removal of the condyles.

CONCLUSION

The endoscopic transoral and transnasal approaches to the CVJ should be viewed as complementary routes as opposed to strict alternatives.

Challenging reconstructive techniques for skull base defect following endoscopic endonasal approaches

OBJECTIVE

We assessed the outcomes of various reconstructive methods for skull base defect after endoscopic endonasal approaches (EEA) depending on the degree of intraoperative cerebrospinal fluid (CSF) leaks.

METHODS

Between Jan. 2008 and Sep. 2009, 122 consecutive patients underwent 124 EEA for sellar and extra-sellar lesions. Intraoperative CSF leaks were classified as grade 0, no intraoperative CSF leak; grade 1, low output; and grade 2, high-output based on the degree of CSF leakage and size of opening in the arachnoid membrane (<5 or ≥5 mm).

RESULTS

Postoperative CSF leaks or meningitis occurred in 13 of 124 cases (10.5%). In 77 patients with grade 0, there was no postoperative CSF leak. Among 20 patients with grade 1 CSF leaks, four patients developed meningitis or postoperative CSF leak. Postoperative CSF leaks occurred in nine of 26 patients (34.6%) with grade 2 leaks. Comparison of reconstructive methods revealed that gasket-seal method provided better control of CSF leaks than free-fat graft in patients with grade 2 leaks (11.8% vs. 66.7%, p = 0.028). However, in grades 0 and 1, we found no difference among the various reconstructive methods.

CONCLUSION

The selection of reconstructive methods for skull base defects should be determined by the degree of CSF leaks. Although grade 0 or 1 leak requires relatively conservative management such as simple closure or free-tissue grafting, a more aggressive reconstructive technique is required to prevent postoperative complication in grade 2 CSF leak.

A simple and versatile tissue adhesive applicator for endonasal endoscopic skull base surgery

Repair of dural defects following endonasal endoscopic cranial base surgery remains a challenge. A variety of reconstructive techniques have been described, many of which utilize tissue adhesives or glues. One of the main difficulties with the endonasal use of these sealants is the available applicators, which often result in the imprecise and excessive application of the material. In this report, we describe the modified use of straight and curved suction tips as simple and versatile rigid tissue adhesive/glue applicators for use during endonasal skull base surgery.

Technologic innovations in neuroendoscopic surgery

Neuroendoscopic surgery encompasses minimally invasive approaches to the skull base using endoscopic techniques. There are unique technologic challenges with endoscopic endonasal skull base surgery, such as a limited working space, difficulty in visualization and identification of neurovascular structures and removal of tissue, hemostasis, and dural reconstruction. Technologic advances that have enabled this surgery include specialized operating suites, neurophysiologic monitoring, imaging and visualization technologies, dissection instrumentation, hemostatic materials, and reconstructive materials. Advances in each of these areas and the needs and challenges of the future of neuroendoscopic surgery are discussed.

A New Technique for Dural Suturing With Fascia Graft for Cerebrospinal Fluid Leakage in Transsphenoidal Surgery

Objective:

One of the most common postoperative complications of surgery using a transsphenoidal approach is cerebrospinal fluid (CSF) leakage, which typically results from inadequate repair of a CSF fistula created at the time of the initial operation. Most techniques use autologous tissue grafts of fat, muscle, or fascia lata, with or without the use of postoperative lumbar CSF drainage; however, patients demonstrate a relatively high incidence of CSF rhinorrhea, especially after extended procedures. We have developed a new technique of dural suturing with fascia graft using special suture-tying microinstruments.

Methods:

Twenty-one consecutive patients with suprasellar tumors underwent dural suturing with fascia graft via new suture-tying microinstruments between January 2004 and December 2007. The 21 patients were retrospectively divided into 2 groups according to the transsphenoidal technique used. Group 1 consisted of 16 patients whose large dural defects were closed with a fascia graft suture for CSF leakage during or after an extended transsphenoidal approach. Group 2 consisted of 5 patients whose dural defects were closed with a fascia graft suture for postoperative CSF rhinorrhea after a conventional transsphenoidal approach.

Results:

None of the 21 patients developed any clinical symptoms of CSF leakage. There were no complications or infections. For 8 patients in group 1 and the 5 patients in Group 2, no postoperative lumbar drainage was performed after dural suturing with fascia graft, and none of the 13 patients developed postoperative CSF rhinorrhea.

Conclusion:

Our dural suturing technique with fascia graft may be more reliable than the conventional packing technique in achieving watertight dural closure and for the prevention of postoperative CSF rhinorrhea. Watertight dural suturing with fascia graft and the leaking point suture could allow surgeons to avoid unnecessary postoperative lumbar drainage.

Management of unexpected cerebrospinal fluid leak during endoscopic sinus surgery

PURPOSE OF REVIEW

Cerebrospinal fluid leak during endoscopic sinus surgery is a potentially devastating complication; however, identification and appropriate management can prevent unfavorable outcomes. The purpose of this review is to outline the recent advances in the management of cerebrospinal fluid leaks that occur during endoscopic sinus surgery.

RECENT FINDINGS

The low incidence of this complication makes prospective and randomized study difficult. The expanding role for endoscopic skull base surgery has brought new techniques and advances in the treatment of skull base reconstruction and cerebrospinal fluid fistula repair that can be applied to intraoperative leaks that occur during sinus surgery. Recent reports have focused on the prevention, identification, repair materials, repair technique, and infectious sequelae related to this complication.

SUMMARY

Several successful techniques that utilize a variety of materials are available for the repair of cerebrospinal fluid leaks encountered during sinus surgery. The clinical scenario will determine the appropriate use of repair material, technique, and postoperative care.

Use of self-closing U-clips for dural repair in mini-invasive surgery for herniated disc

OBJECT

The feasibility of a new technique of dural repair (self-closing U-clips) in mini-invasive surgery for herniated disk is demonstrated in this case report.

MATERIALS AND METHODS

A 44-year-old male patient underwent lumbar microdiscectomy at out Institute, with subsequent dural leak as surgical complication; the dural leak re-appeared even after a second intervention in which we used muscle and dural graft and fibrin glue to repair the leak. We then decided to employ self-closing nitinol- U-clip to achieve primary dural closure.

RESULTS

After the intervention the patient no more presented signs or symptoms due to the unintended durotomy, and the postoperative course was uneventful.

CONCLUSION

Self-closing nitinol U-clips (Medtronic, Inc., Minneapolis) can be used for closing a dural tear through a mini-invasive approach that could make a conventional microsuturing technique very difficult.