Treatment of traumatic cerebrospinal fluid rhinorrhea via extended extradural anterior skull base approach

To describe and assess the repair technique and perioperative management for cerebrospinal fluid(CSF)leak resulting from extensive anterior skull base fracture via extradural anterior skull base approach.;This was a retrospective review conducted at the Department of Neurosurgery of the Shanghai Tenth People's Hospital from January 2015 to April 2020.Patients with traumatic CSF rhinorrhea resulting from extensive anterior skull base fracture treated surgically via extended extradural anterior skull base approach were included in this study.The data of medical and radiological records,surgical approaches,repair techniques,peritoperative management,surgical outcome and postoperative follow-up were analyzed.Surgical repair techniques were tailored to the condition of associated injuries of the scalp,bony and dura injuries and associated intracranial lesions.Patients were followed up for the outcome of CSF leak and surgical complications.Data were presented as frequency and percent.;Thirty-five patients were included in this series.The patients'mean age was 33 years(range 11-71 years).Eight patients were treated surgically within 2 weeks;while the other 27 patients,with prolonged or recurrent CSF rhinorrhea,received the repair surgery at 17 days to 10 years after the initial trauma.The mean overall length of follow-up was 23 months(range 3-65 months).All the patients suffered from frontobasal multiple fractures.The basic repair tenet was to achieve watertight seal of the dura.The frontal pericranial flap alone was used in 20 patients,combined with temporalis muscle and/or its facia in 10 patients.Free fascia lata graft was used instead in the rest 5 patients.No CSF leak was found in all the patients at discharge.There was no surgical mortality in this series.Bilateral anosmia was the most common complication.At follow-up,no recurrent CSF leak or meningitis occurred.No patients developed mucoceles,epidural abscess or osteomyelitis.One patient ultimately required ventriculoperitoneal shunt because of progressive hydrocephalus.;Traumatic CSF rhinorrhea associated with extensive anterior skull base fractures often requires aggressive treatment via extended intracranial extradural approach.Vascularized tissue flaps are ideal grafts for cranial base reconstruction,either alone or in combination with temporalis muscle and its fascia---fascia lata sometimes can be opted as free autologous graft.The approach is usually reserved for patients with traumatic CSF rhinorrhea in complex frontobasal injuries.

Frontal lobe position after single-layer cadaveric dermal matrix repair of large anterior skull base defects

Objective:Endoscopic repair of large anterior skull base(ASB)defects has excellent results when using multilayered repairs with a nasoseptal flap.However,in extensive intranasal tumors,a nasoseptal flap may not always be available.One alternative option is a flexible single-layer ASB repair.Initial studies indicate low cerebrospinal fluid leak rates with a single-layer repair.However,the level of frontal lobe support,particularly the propensity for a significant inferior displacement of the frontal lobe,is not known.The goal of this study is to determine the frontal lobe position after single-layer acellular dermal allograft repair in large ASB defects.Study Design:Retrospective cohort study.Setting:Tertiary care medical center.Subjects and Methods:This cohort study compares the frontal lobe position in adults who underwent endoscopic endonasal ASB tumor resection and single-layer cadaveric dermal matrix repair(ASB cohort)with control subjects without intracranial abnormalities(control cohort).The ASB cohort includes subjects with an ASB defect of≥5 cm anterior/posterior and≥1.5 cm wide and who had imaging at least 2 months after surgery.The frontal lobe position is measured on sagittal CT/MRI using a reference line from the base of the sella to the nasion.A value of zero indicates that the inferior-most aspect of the frontal lobe is at the level of the nasion-sellar line.A positive value indicates that the frontal lobe is inferior to the nasion-sellar line.The ASB cohort frontal lobe position is compared with the control cohort using the Mann-WhitneyU test.A priori we set an absolute difference of 5 mm as a clinically significant difference.Results:The ASB cohort includes 47 subjects who are 57%male with an average age of 60 years(range:31-89 years).The most common ASB pathology is esthesioneuroblastoma(n=21)and 81%of the ASB cohort had postoperative radiation.The control cohort includes 20 subjects who are 60%male,with a mean age of 45 years(range:19-74 years).The majority of controls underwent imaging for head trauma(n=13).The ASB mean frontal lobe position is-0.2 mm superior to the nasion-sellar line(range:-9.2 to 10.4 mm),while the control’’s mean frontal lobe position is 1.1 mm inferior to the nasion-sellar line.This difference is not statistically significant(P=0.13)and does not reach our a priori definition of clinical significance.The frontal lobe position of ASB subjects who had radiation is closer to the nasion-sellar line as compared with those who did not undergo radiation.Conclusions:Single-layer acellular dermal graft repair maintains frontal lobe support and position in large ASB defects.

Skull repair materials applied in cranioplasty: History and progress

The skull provides protection and mechanical support, and acts as a container for the brain and its accessory organs. Some defects in the skull can fatally threaten human life.Many efforts have been taken to repair defects in the skull, among which cranioplasty is the most prominent technique. To repair the injury, numerous natural and artificial materials have been adopted by neurosurgeons. Many cranioprostheses have been tried in the past decades, from autoplast to bioceramics. Neurosurgeons have been evaluating their advantages and shortages through clinical practice. Among those prostheses, surgeons gradually prefer bionic ones due to their marvelous osteoconductivity,osteoinductivity, biocompatibility, and biodegradability. Autogeneic bone has been widely recognized as the "gold standard" for renovating large-sized bone defects. However, the access to this technique is restricted by limited availability and complications associated with its use. Many metal and polymeric materials with mechanical characteristics analogous to natural bones were consequently applied to cranioplasty. But most of them were unsatisfactory concerning osteoconductiion and biodegradability owe to their intrinsic properties. With the microstructures almost identical to natural bones, mineralized collagen has biological performance nearly identical to autogeneic bone, such as osteoconduction. Implants made of mineralized collagen can integrate themselves into the newly formed bones through a process called "creeping substitution". In this review, the authors retrospect the evolution of skull repair material applied in cranioplasty. The ultimate skull repair material should have microstructure and bioactive qualities that enable osteogenesis induction and intramembranous ossification.