Cerebrospinal fluid leak after endoscopic skull base surgery

Cerebrospinal fluid leak after endoscopic skull base surgery

Although rates of postoperative morbidity and mortality have become relatively low in patients undergoing transnasal transsphenoidal surgery (TSS) for pituitary adenomacerebrospinal fluid fistulas remain a major driver of postoperative morbidity. Persistent CSF fistulas harbor the potential for headache and meningitis.

Staartjes et al., trained and internally validated a robust deep neural network-based prediction model that identifies patients at high risk for intraoperative CSF. Machine learning algorithms may predict outcomes and adverse events that were previously nearly unpredictable, thus enabling safer and improved patient care and better patient counseling 1).


The objective of a study of Umamaheswaran et al., was to assess the incidence of CSF leak following pituitary surgery and the methods of effective skull base repair. This retrospective observational study conducted in a tertiary care hospital after obtaining due clearance from the Institutional ethics committee. The charts of patients who underwent endonasal pituitary surgery between 2013 and 2018 were studied and details noted. Patients undergoing revision surgery or with history of preoperative radiotherapy were excluded from the study. 52 patients were included in the study. Based on the type of CSF leak, the patients were grouped into four. 19 patients (36.5%) had an intraoperative CSF leak. 3 patients developed a postoperative CSF leak. Based on the histopathology, 4 patients had ACTH secreting tumor. 8 patients had growth hormone secreting tumor, 22 had gonadotropin secreting tumor, 9 patients had a non-functioning tumour and 9 patients had prolactinoma. The type of skull base repair performed in these patients were grouped into 4.18 patients underwent type I repair, 21 patients underwent type II repair, 8 patients underwent type III repair and 5 patients underwent type IV repair. They observed that the pedicled nasoseptal flap is particularly advantageous over other repair techniques, especially in low pressure leaks. The strategy for skull base repair should be tailored to suit each patient to minimise the occurrence of morbidity and the duration of hospital stay 2).


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.

Xie et al. 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.

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.

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 3).

In-Hospital Costs

All endoscopic transsphenoidal approach for pituitary surgeries performed from January 1, 2015, to October 24, 2017, with complete data were evaluated in a retrospective single-institution study. The electronic medical record was reviewed for patient factors, tumor characteristics, and cost variables during each hospital stay. Multivariate linear regression was performed using Stata software.

The analysis included 190 patients and average length of stay was 4.71 days. Average total in-hospital cost was $28,624 (95% confidence interval $25,094-$32,155) with average total direct cost of $19,444 ($17,136-$21,752) and total indirect cost of $9181 ($7592-$10,409). On multivariate regression, post-operative cerebrospinal fluid (CSF) leak was associated with a significant increase in all cost variables, including a total cost increase of $40,981 ($15,474-$66,489, P = .002). Current smoking status was associated with an increased total cost of $20,189 ($6,638-$33,740, P = .004). Self-reported Caucasian ethnicity was associated with a significant decrease in total cost of $6646 (-$12,760 to -$532, P = .033). Post-operative DI was associated with increased costs across all variables that were not statistically significant.

Post-operative CSF leak, current smoking status, and non-Caucasian ethnicity were associated with significantly increased costs. Understanding of cost drivers of endoscopic transphenoidal pituitary surgery is critical for future cost control and value creation initiatives 4).

Case series

see Cerebrospinal fluid leak after endoscopic skull base surgery case series.

References

1)

Staartjes VE, Zattra CM, Akeret K, Maldaner N, Muscas G, Bas van Niftrik CH, Fierstra J, Regli L, Serra C. Neural network-based identification of patients at high risk for intraoperative cerebrospinal fluid leaks in endoscopic pituitary surgery. J Neurosurg. 2019 Jun 21:1-7. doi: 10.3171/2019.4.JNS19477. [Epub ahead of print] PubMed PMID: 31226693.
2)

Umamaheswaran P, Krishnaswamy V, Krishnamurthy G, Mohanty S. Outcomes of Surgical Repair of Skull Base Defects Following Endonasal Pituitary Surgery: A Retrospective Observational Study. Indian J Otolaryngol Head Neck Surg. 2019 Mar;71(1):66-70. doi: 10.1007/s12070-018-1511-4. Epub 2018 Oct 15. PubMed PMID: 30906716; PubMed Central PMCID: PMC6401034.
3)

Xie T, Zhang X, Gu Y, Sun C, Liu T. A low cost and stepwise training model for skull base repair using a suturing and knotting technique during endoscopic endonasal surgery. Eur Arch Otorhinolaryngol. 2018 Jun 1. doi: 10.1007/s00405-018-5024-2. [Epub ahead of print] PubMed PMID: 29858924.
4)

Parasher AK, Lerner DK, Glicksman JT, et al. Drivers of In-Hospital Costs Following Endoscopic Transphenoidal Pituitary Surgery [published online ahead of print, 2020 Aug 24]. Laryngoscope. 2020;10.1002/lary.29041. doi:10.1002/lary.29041

Skull base chondrosarcoma outcome

Skull base chondrosarcoma outcome

Chondrosarcomas are relatively slow growing but locally aggressive. Local resection is often the treatment of choice. Radiotherapy may sometimes be employed although sensitivity is thought to be minimal. Metastatic spread is uncommon.


High-dose, double-scattered 3D conformal proton therapy alone or following surgical resection for skull-base chondrosarcoma is an effective treatment with a high rate of local control with no acute grade 3 radiation-related toxicity 1).


In 2010 Bloch et al. published an extensive systematic review of the English literature. The patients were stratified according to treatment modality, treatment history, histological subtype, and histological grade, and the recurrence rates were analyzed. A total of 560 patients treated for cranial chondrosarcoma were included. Five-year recurrence rate among all patients was 22% with median follow-up of 60 months and median disease-free interval of 16 months. Tumor recurrence was more common in patients who only received surgery or had mesenchymal subtype tumors 2).

Pencil-beam scanning proton therapy is an effective treatment for skull base tumors with acceptable late toxicity. Optic apparatus and/or brainstem compression, histology and gross tumor volume (GTV) allow independent prediction of the risk of local failure and death in skull base tumor patients 3).


Dibas et al. aimed to evaluate the incidence and survival rates and trends of skull base chondrosarcomas (SBC).

Data from SBC patients between 1975 and 2017 were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. The age-adjusted rates (AAR) were calculated for the overall cases and based on gender, age, race, and histology. Furthermore, the relative survival rates for one, three, and five years, and the rates stratified to the aforementioned selected variables were computed. Besides, they conducted a joint point regression analysis to calculate the annual percent change (APC) and its associated standard error (SE) for AAR and mortality.

The AAR rate of SBC was 0.019 per 100,000. Higher AAR rates were observed in patients who were in the 65-74-year-age-group, females, Caucasians, and had none mesenchymal subtype. The relative one-year, three-year and five-year-survival rates were 99.58 %, 93.67 %, and 89.10 %, respectively. Lower survival rates were noted in patients who were males, African Americans, and had a mesenchymal subtype. The trend analysis has shown a significant yearly increase (P < 0.001) in AAR of SBC (APC ± SE = 0.0005 %±0.0001), along with a significant yearly decline in mortality rates (APC ± SE= -0.0202 %±0.0029).

Despite the increase in AAR over time, there has been a significant decline in mortality rates over time, which might have been due to the advancement of treatment modalities, improvement in diagnostic imaging, and modification in disease grading 4).

References

1)

Holtzman AL, Rotondo RL, Rutenberg MS, et al. Proton therapy for skull-base chondrosarcoma, a single-institution outcomes study. J Neurooncol. 2019;142(3):557-563. doi:10.1007/s11060-019-03129-8
2)

Bloch OG, Jian BJ, Yang I, et al. Cranial chondrosarcoma and recurrence. Skull Base. 2010;20(3):149-156. doi:10.1055/s-0029-1246218
3)

Weber DC, Malyapa R, Albertini F, et al. Long term outcomes of patients with skull-base low-grade chondrosarcoma and chordoma patients treated with pencil beam scanning proton therapy. Radiother Oncol. 2016;120(1):169-174. doi:10.1016/j.radonc.2016.05.011
4)

Dibas M, Doheim MF, Ghozy S, Ros MH, El-Helw GO, Reda A. Incidence and survival rates and trends of skull Base chondrosarcoma: A Population-Based study [published online ahead of print, 2020 Aug 11]. Clin Neurol Neurosurg. 2020;198:106153. doi:10.1016/j.clineuro.2020.106153

Webinar Topic: Anatomy of Skull Base – Prof. Saleem Abdulrauf

WEBINAR # 22

Topic: Anatomy of Skull Base – Prof. Saleem Abdulrauf
Time: May 11, 2020 17:00 Islamabad, Karachi, Tashkent

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https://zoom.us/j/95840858062

Meeting ID: 958 4085 8062

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