Clinical and technical factors in endoscopic skull base surgery associated with reconstructive success.

BACKGROUND: In this study, we identified key discrete clinical and technical factors that may correlate with primary reconstructive success in endoscopic skull base surgery (ESBS). METHODS: ESBS cases with intraoperative cerebrospinal fluid (CSF) leaks at four tertiary academic rhinology programs were retrospectively reviewed. Logistic regression identified factors associated with surgical outcomes by defect subsite (anterior cranial fossa [ACF], suprasellar [SS], purely sellar, posterior cranial fossa [PCF]). RESULTS: Of 706 patients (50.4% female), 61.9% had pituitary adenomas, 73.4% had sellar or SS defects, and 20.5% had high-flow intraoperative CSF leaks. The postoperative CSF leak rate was 7.8%. Larger defect size predicted ACF postoperative leaks; use of rigid reconstruction and older age protected against sellar postoperative leaks; and use of dural sealants compared to fibrin glue protected against PCF postoperative leaks. SS postoperative leaks occurred less frequently with the use of dural onlay. Body-mass index, intraoperative CSF leak flow rate, and the use of lumbar drain were not significantly associated with postoperative CSF leak. Meningitis was associated with larger tumors in ACF defects, nondissolvable nasal packing in SS defects, and high-flow intraoperative leaks in PCF defects. Sinus infections were more common in sellar defects with synthetic grafts and nondissolvable nasal packing. CONCLUSIONS: Depending on defect subsite, reconstructive success following ESBS may be influenced by factors, such as age, defect size, and the use of rigid reconstruction, dural onlay, and tissue sealants.

Recurrence rates of de-novo versus inverted papilloma-transformed sinonasal squamous cell carcinoma: a meta-analysis.

BACKGROUND: There is a paucity of reporting on recurrence patterns of de-novo sinonasal squamous cell carcinoma (DN-SCC) and inverted-papilloma-transformed sinonasal squamous cell carcinoma (IP-SCC). METHOD: A systematic literature review queried studies comparing recurrence patterns in patients with both DN-SCC and IP-SCC. Primary outcomes included local and regional recurrence and rates of distant metastasis. Of the 595 studies screened, eight were included. RESULTS: Patients with DN-SCC had significantly higher rates of positive margins, advanced T classification (T3/T4), treatment with chemotherapy and radiotherapy. There were no significant differences in local recurrence or regional recurrence. Overall risk of distant metastasis was lower in IP-SCC. DN-SCC, compared to IP-SCC, is more likely to present with advanced TNM classification and have positive margins after surgical resection, which may affect rates of distant metastasis and recurrence. CONCLUSIONS: The findings in this study suggest IP-SCC may be a less aggressive malignancy compared to DN-SCC, with the possibility of a reduced role for adjuvant therapy in IP-SCC. Further studies are required to better understand differences in tumor biology and treatments strategies between IP-SCC and DN-SCC.

The fate of the bone graft in cerebrospinal fluid rhinorrhea endoscopic repair for idiopathic intracranial hypertension: a retrospective case series analysis.

INTRODUCTION: Idiopathic intracranial hypertension (IIH) is a common cause of spontaneous cerebrospinal fluid (CSF) leaks necessitating surgical intervention, and grafting of septal, mastoid, or turbinate bone over the defect is increasingly performed to strengthen the repair of the primary defect. However, the postoperative fate of these grafted bone fragments is largely unknown. METHODOLOGY: We performed a retrospective study of patients at the University of Pennsylvania undergoing repair of spontaneous CSF leaks secondary to IIH. Preoperative and postoperative CTs were analyzed to determine the integration status of the transplanted bone. RESULTS: Fourteen patients with IIH and spontaneous CSF leak were analyzed, with a mean postoperative imaging follow-up period of four years. Thirteen patients (93%) had bone present on CT imaging, with 11 of these patients displaying evidence of bone integration. Two patients (14%) had a recurrent CSF leak in the same area, including the patient with absence of bone on imaging follow-up. CONCLUSIONS: Bone grafts frequently incorporate when used for repair of spontaneous CSF leaks associated with IIH. The rate of incorporation is comparable to bone grafts used for other etiologies of CSF leak, despite the increased pressure on the repair site. Any rigid repair of the leak site should likely be accompanied by treatment of the underlying intracranial hypertension to avoid leak recurrence.

Reconstructive challenges in the extended endoscopic transclival approach.

OBJECTIVE: We wanted to present our experience with the extended endoscopic approach to clival pathology, focusing on cerebrospinal fluid leak and reconstruction challenges. METHODS: We examined a consecutive series of 37 patients undergoing the extended endoscopic approach for skull base tumours, 9 patients with clival pathology. Patients were examined for the incidence of post-operative cerebrospinal fluid leak in relation to tumour pathology, location, size, reconstruction and lumbar drain. RESULTS: The overall incidence of post-operative cerebrospinal fluid leak was 10.8 per cent. Seventy-five per cent of patients who had a post-operative cerebrospinal fluid leak underwent a transclival approach (p < 0.05). All patients with clival pathology who underwent an intradural dissection had a post-operative cerebrospinal fluid leak (p < 0.05). CONCLUSION: Post-operative cerebrospinal fluid leak rates after the extended endoscopic approach have improved significantly after advancements including the vascularised nasoseptal flap. Despite this, transclival approaches continue to pose much difficulty. Further investigation is necessary to develop technical improvements that can meet the unique challenges associated with this region.

MR imaging evolution of endoscopic cranial defect reconstructions using nasoseptal flaps and their distinction from neoplasm.

BACKGROUND AND PURPOSE: Endoscopic endonasal approach is the procedure of choice for the resection of ventral skull base neoplasms, with defect closure requiring multilayer reconstruction. This study evaluates the temporal MR imaging evolution of nasoseptal flaps and free grafts used in endoscopic skull base reconstruction. MATERIALS AND METHODS: Sixty-nine follow-up brain MRIs of 22 patients who had endoscopic skull base reconstruction using 26 nasoseptal flaps combined with 8 collagen-matrix dural grafts, 10 fascia lata grafts, and 10 intracranial fat grafts were retrospectively reviewed. Temporal changes in signal intensity, enhancement, thickness, and the configuration of reconstructive layers were evaluated. Tissue with signal intensity or enhancement different from that of normal evolving reconstructive layers at the surgical bed was evaluated, and its association with clinically confirmed tumor was assessed with the Fisher exact test. RESULTS: All normal reconstructive layers were retracted to cranial defects and showed maturation of imaging features within 2-6 months. The immediate postoperative T2-isointensity to brain and enhancement of nasoseptal flaps persisted, but the flap thickness was reduced by 20%-30% (average thickness, 4.5 ± 1.3 mm); additionally, the C shape and vascular pedicle of the nasoseptal flaps became indistinct, but the flap location remained unchanged. The initial appearance of the nonenhancing fascia lata with variable T2 signal intensity became enhancing with increasing T2-hypointensity and a graft-thickness reduction of ≥50% (average thickness, 3.5 ± 1.6 mm). All fat grafts showed progressive resorption. In 6 patients, abnormal tissue represented residual or recurrent tumor (P = .0001). CONCLUSIONS: Maturation and stability of multilayer endoscopic skull base reconstructions on MR imaging occurs within 2-6 months postoperatively. Understanding of the normal imaging evolution of endoscopic skull base reconstructions is essential to distinguish them from neoplasms.

Endoscopic sinus surgery: evolution and technical innovations.

Prior to the introduction of functional endoscopic sinus surgery, several surgeons had begun to use telescopes to perform surgical procedures in the nose and sinuses. However, the central concepts of functional endoscopic sinus surgery evolved primarily from Messerklinger's endoscopic study of mucociliary clearance and endoscopic detailing of intranasal pathology. The popularity of a combination of endoscopic ethmoidectomy plus opening of secondarily involved sinuses grew rapidly during the latter part of the twentieth century, and endoscopic intranasal techniques began to expand to deal with pathology other than inflammation. We present a review of the evolution of knowledge regarding the pathogenesis of inflammatory sinus disease since that point in time, and of the impact that this has had on the management of inflammatory sinus disease. We also detail the technological advances that have allowed endoscopic intranasal techniques to expand and successfully treat other pathology, including skull base and orbital disease. In addition, we describe evolving technologies which may further influence development within this field.