Risk Factors for Postoperative Cerebrospinal Fluid Leak after Graded Multilayer Cranial Base Repair with Suturing via the Endoscopic Endonasal Approach

This study analyzed risk factors for postoperative cerebrospinal fluid (CSF) leak after graded multilayer cranial base repair method with dural suturing. We performed surgery via the endoscopic endonasal approach (EEA) from 2012.6 to 2018.4, and those consecutive clinical data were prospectively accumulated and retrospectively analyzed. We tailored the repair method according to the intraoperative CSF leak grade. Among 388 surgeries via the EEA, there were 10 (2.6%) cases of postoperative CSF leak after graded repair with suturing. Postoperative CSF leak occurred in two of the 150 cases without intraoperative CSF leak (grade 0), one of the 104 cases with small (grade 1) intraoperative CSF leak, two of the 60 cases with moderate (grade 2) leak, and five of the 74 cases with large (grade 3) leak. Univariate analysis indicated that chordoma (P = 0.023), estimated tumor volume ≥ 7400 mm³ (P = 0.003), and maximum tumor diameter ≥ 32.5 mm (P = 0.001) were significant risk factors for postoperative CSF leak. Additionally, among cases with intraoperative grade 3 CSF leak, chordoma (P = 0.021), estimated tumor volume ≥ 23000 mm³ (P = 0.003), and maximum tumor diameter ≥ 45.5 mm (P = 0.001) were significant risk factors for postoperative CSF leak. Maximum tumor diameter, estimated tumor volume, and chordoma tumor pathology are related to a higher risk of postoperative CSF leak.

Application of a Minimally Invasive Liposuction Technique for Harvesting Fat during Transsphenoidal Surgery: A Technical Note

Secure reconstruction in transsphenoidal surgery (TSS) is important for the prevention of the major and serious complication of postoperative cerebrospinal fluid (CSF) leak. Although abdominal fat can be safely and effectively used as a reconstruction tissue, harvesting it from the abdominal wall is traumatic and invasive, resulting in cosmetic problems. In this report, we present a method of harvesting abdominal fat using a minimally invasive liposuction technique to avoid cosmetic issues. Since 2016, we have been using fat harvested from the abdominal wall by suctioning with a dedicated syringe for reconstruction after TSS in selected cases. The liquefied fat obtained by the liposuction technique was wrapped with an oxycellulose sheet and changed its form to what we termed “fatty candy”. In this form, the fat maintained its configuration and could be handled almost as easily as a conventional fat graft. In our experienced series, there was no case with wound complication nor postoperative or late-onset CSF leak during a postoperative follow-up of at least 3 months. The fat harvested by this simple and minimally invasive liposuction technique can be expected to provide an autologous graft that is adequate not only for prevention of cosmetic problems but also for prevention of postoperative CSF leak.

Effect of thrombin concentration on the adhesion strength and clinical application of fibrin glue-soaked sponge

Fibrin glue-soaked gelatin sponge (FGGS) has been used for tissue sealing in neurosurgical practice, but too rapid clotting of fibrin glue occasionally prevents good fixation of FGGS. Dilution of thrombin may provide adequate manipulation time between mixing fibrinogen and thrombin on gelatin sponge and application into the tissue defects. The present study characterized the effect of thrombin dilution on the adhesion strength of FGGS and retrospectively assessed the clinical usage of the dilution for filling dead space or sealing arachnoid defect in 255 cases who underwent transsphenoidal surgery for the last 66 months. FGGS was prepared using three different concentrations of thrombin: 250 (standard), 50 (1:5 dilution), and 25 (1:10 dilution) units/ml, and incubated for three different periods (5, 20, and 60 seconds). FGGSs were applied over two adjacently positioned porcine skins placed on two metallic plates. The adhesion strength was evaluated by measuring maximum tensile strength during pulling out the sliding plate at a constant rate of displacement. The maximum adhesion strength was greater for FGGS with 1:10 diluted thrombin solution than for FGGS prepared with higher concentrations (p < 0.05). Adhesion strength did not decay for 20 seconds after the mixture. Only four of 255 cases (1.6%) required second reconstruction of sella floor due to the cerebrospinal fluid leakage. FGGS prepared with diluted thrombin solution can provide adequate adhesion strength for clinical use.