Collagen sponge repair of small cerebrospinal fluid leaks obviates tissue grafts and cerebrospinal fluid diversion after pituitary surgery

Skull base repair following endonasal pituitary and skull base tumour resection: a systematic review

PURPOSE

Postoperative cerebrospinal fluid rhinorrhoea (CSFR) remains a frequent complication of endonasal approaches to pituitary and skull base tumours. Watertight skull base reconstruction is important in preventing CSFR. We sought to systematically review the current literature of available skull base repair techniques.

METHODS

Pubmed and Embase databases were searched for studies (2000-2020) that (a) reported on the endonasal resection of pituitary and skull base tumours, (b) focussed on skull base repair techniques and/or postoperative CSFR risk factors, and (c) included CSFR data. Roles, advantages and disadvantages of each repair method were detailed. Random-effects meta-analyses were performed where possible.

RESULTS

193 studies were included. Repair methods were categorised based on function and anatomical level. There was absolute heterogeneity in repair methods used, with no independent studies sharing the same repair protocol. Techniques most commonly used for low CSFR risk cases were fat grafts, fascia lata grafts and synthetic grafts. For cases with higher CSFR risk, multilayer regimes were utilized with vascularized flaps, gasket sealing and lumbar drains. Lumbar drain use for high CSFR risk cases was supported by a randomised study (Oxford CEBM: Grade B recommendation), but otherwise there was limited high-level evidence. Pooled CSFR incidence by approach was 3.7% (CI 3-4.5%) for transsphenoidal, 9% (CI 7.2-11.3%) for expanded endonasal, and 5.3% (CI 3.4-7%) for studies describing both. Further meaningful meta-analyses of repair methods were not performed due to significant repair protocol heterogeneity.

CONCLUSIONS

Modern reconstructive protocols are heterogeneous and there is limited evidence to suggest the optimal repair technique after pituitary and skull base tumour resection. Further studies are needed to guide practice.

Reconstruction of skull base bone defects using an in situ bone flap after endoscopic endonasal transplanum-transtuberculum approaches

PURPOSE

The creation of bone flaps which can be later repositioned and fixed in situ for repairing the bone defects during the endoscopic endonasal approaches (EEAs)-similar to transcranial craniotomies-is still a challenge. We present an in situ bone flap (ISBF) closure for the repair of bone defects after endoscopic endonasal transplanum-transtuberculum approaches (EETAs).

METHODS

A retrospective analysis of consecutive patients who underwent the EETAs between January 2016 and February 2019 was performed. According to whether or not to use ISBF for skull base reconstruction, these patients were divided into the ISBF group or the non-ISBF group.

RESULTS

Of 47 patients in the ISBF group, only one patient (2.1%) developed postoperative cerebrospinal fluid (CSF) leakage, yielding a significantly lower leakage rate in the ISBF group than in the non-ISBF group (6 of 38, 15.8%, P = 0.042). Besides, when only comparing cases of hydrocephalus in the two groups, the CSF leakage rate in the ISBF group was 8.3% (1/12), which was still significantly lower than that in the non-ISBF group (62.5%, 6/8) (P = 0.018). Postoperative CSF leakages in both groups were successfully treated with lumbar drainage alone, and no cases of injury to the internal carotid arteries or optic nerves occurred in either group.

CONCLUSIONS

An ISBF closure similar to transcranial craniotomies with repositioning bone flap in situ-is feasible, safe, and reliable. The ISBF closure combining with a pedicled nasoseptal flap (PNSF) provides the cranial base surgeon with an additional repair method that has demonstrated effectiveness at facilitating a more stable and durable reconstruction and reducing CSF leaks.

Bilaminar Chitosan Scaffold for Sellar Floor Repair in Transsphenoidal Surgery

Background

Endoscopic endonasal transsphenoidal surgery (EETS) is a standard technique used to approach sellar tumors. It is relatively safe, minimally invasive and carries a low risk of complications. However, one of the common complications reported with this technique is CSF leakage which causes morbidity, an increase in recovery time and hospital costs. This complication usually occurs from violation of the diaphragma sellae and a defect in the structures of the sellar floor or incomplete repair. In this article we report the first case with the use of a novel bilaminar chitosan scaffold which can be potentially used in the repair of the sellar floor, primarily aiming to the bony part of this structure.

Case Presentation

After a personalized design employing a tissue engineering strategy, we reconstructed the sellar floor in a 65-year-old woman who had undergone EETS for a pituitary adenoma with progressive bilateral visual loss. To repair the bony defect of the sellar floor, we used a novel bilaminar chitosan scaffold. The patient had an unremarkable postoperative course with no evidence of CSF leak. The polymer was well tolerated without toxicity, infection or complications. After 2 years of follow up the patient remains neurologically intact, and in good endocrinological status.

Conclusion

This is the first report of the use of this biomaterial and its biocompatibility in a clinical setting for the repair of the sellar floor during EETS. Our experience with chitosan bilaminar scaffold and in several preclinical studies in the literature have demonstrated good biocompatibility and effective bioengineered bone regeneration due to its excellent osteoconductive properties, this study pretends to be one landmark for further clinical research and larger case series with the use of this personalized tissue engineering materials in order to see they real efficacy to increase the surgeon armamentarium.

An Absorbable Collagen Biomembrane Help Improve Swallowing Function After Anterior Cervical Spine Surgery

The objective of this study is to investigate the changes in swallowing function after using an absorbable collagen biomembrane during anterior cervical spine surgery (ACSS). A prospective controlled study of patients who underwent two-level anterior cervical decompression and fusion (ACDF) with a zero-profile implant or single-level anterior cervical corpectomy and fusion (ACCF) with cage and plate fixation was performed in our hospital from January 2016. An absorbable collagen biomembrane was used after suturing the prevertebral fascia in the experimental groups. The thickness of prevertebral soft tissue (PST) was measured on lateral X-rays to determine the extent of swelling. In addition, the Bazaz grading system and the Swallowing-Quality of Life (SWAL-QOL) survey were used to assess the swallowing function. A total of 100 patients were included with a follow-up of 12 months. Significant differences in PST swelling were found between the experimental groups and control groups at 3 months, 6 months, and 12 months postoperatively (P < 0.05). Patients in the experimental groups had significantly increased SWAL-QOL scores compared with patients in the control groups at 3 months and 6 months after surgery (P < 0.05). A significant difference in the total incidence of dysphagia was observed at 3 months postoperatively between the experimental groups and control groups (P < 0.05). The application of absorbable collagen biomembrane in ACSS can reduce the total incidence of dysphagia and improve swallowing function early after surgery.

Soft tissue grafts for dural reconstruction after meningioma surgery

The meninges are involved in various pathologies and are often directly or indirectly severed during surgical procedures, especially the dura mater. This can pose a real challenge for the surgeon, as a proper reconstruction of the meninges is important to prevent complications such as cerebrospinal fluid leak (CSF). A variety of techniques for dural reconstruction have been described, employing natural and artificial materials. A novel technique for dural reconstruction involves soft tissue grafts in the form of fibrous or fibromuscular flaps, which are placed on the dural defects to seal the gaps. These soft tissue grafts represent an appropriate scaffold for cell ingrowth and fibrosis, thus preventing CSF. In this pilot study, we described the application of soft tissue grafts for dural reconstruction in 10 patients who underwent convexity meningioma surgery.

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.

An Algorithm for Sellar Reconstruction Following the Endoscopic Endonasal Approach: A Review of 300 Consecutive Cases

Objectives/Hypotheses  The endoscopic endonasal approach (EEA) is the workhorse endoscopic procedure for sellar and parasellar pathology. Various reconstruction techniques have been reported following EEA surgery, ranging from no reconstruction to vascularized flaps. We review our institution's experience with sellar reconstruction following EEA and propose an evidence-based algorithm. Design  Retrospective review. Setting  Tertiary academic medical center. Participants  Patients who underwent endoscopic EEA surgery for sellar or parasellar pathology between March 1, 2013 and August 31, 2016. Main Outcome Measures  Patient demographic and clinicopathologic data were collected. Outcome measures included intraoperative and postoperative cerebrospinal fluid (CSF) leak rates and extent of resection (gross or subtotal). Results  Three hundred consecutive patients were included. Depending on the presence and grade of intraoperative CSF leak, cases were reconstructed using either a free mucosal graft (FMG) or nasoseptal flap (NSF). Intraoperative and postoperative CSF leak rates were 30.7% and 2.3%, respectively. Multivariable logistic regression found that intraoperative CSF leak was associated with recurrent disease (odds ratio [OR] 2.47, p  = 0.004), with no apparent predictors of postoperative CSF leak. Conclusions  Based on this large series, we propose the following algorithm for sellar reconstruction: FMG for no CSF leak; fat graft + FMG ± rigid fixation for low-grade leaks; and fat graft + NSF ± rigid fixation for high-grade leaks.

Invagination of the Sphenoid Sinus Mucosa after Endoscopic Endonasal Transsphenoidal Approach and Its Significance

Objective

To describe the clinical features of invagination of the sphenoid sinus mucosa (ISM) and compare them with other similar cases using a visual analog scale (VAS) to assess the various nasal symptoms and to discuss its clinical significance and means of prevention.

Study Design

Retrospective chart review at a tertiary referral center.

Methods

Between 2010 and 2015, 8 patients who had undergone EETSA surgery displayed postoperative ISM. The comparison group consisted of 147 patients who underwent the same surgical procedures and were diagnosed with the same diseases. Pre- or postoperative paranasal sinus computed tomography (PNS CT) and VAS were performed and subsequently analyzed.

Results

The clinical features of ISM of the sphenoid sinus showed sellar floor invagination and regenerated inverted ingrowing sphenoid mucosa on endoscopic imaging. PNS CT also showed a bony defect and invaginated air densities at the sellar turcica. Pre- and postoperative VAS scores revealed that the ISM group had much less of an improvement in headaches after surgery than that of the comparison group (p = 0.049).

Conclusion

ISM may occur because of a change in pressure, sphenoid mucosal status, or arachnoid membrane status. Moreover, ISM is related to improvements in headaches. Therefore, EETSA patients should avoid activities that cause rapid pressure changes during the healing process. In addition, sellar reconstruction that is resistant to physical pressure changes should be mandated despite the absence of an intraoperative CSF leak.

Postoperative Low-Flow Cerebrospinal Fluid Leak of Endoscopic Endonasal Transsphenoidal Surgery for Pituitary Adenoma--Wait and See, or Lumbar Drain?

To assess the effectiveness of continuous lumbar drainage (LD) for management of postoperative cerebrospinal fluid leaks after endoscopic endonasal transsphenoidal approach for resection of pituitary adenoma. Three hundred eighty-four medical records of patients who were admitted to our institute during a 2.5-year period were retrospectively reviewed, 33 of them experienced low-flow cerebrospinal fluid leak postoperatively. If LD was used, all patients with low-flow cerebrospinal fluid leak were classified into 2 groups, lumbar drained group and conservatively treated group. The age, sex, management of cerebrospinal fluid leaks, and related complications were reviewed. Statistical comparisons between the 2 groups were made using SPSS 19.0 (IBM Corp, Armonk, NY). The differences were considered statistically significant if the P value was less than 0.05.Thirty-three of 384 (8.6%) experienced low-flow postoperative cerebrospinal fluid leaks. Cured rate of cerebrospinal fluid leak was 94.4% (17/18) in continuous lumbar drained group, and 93.3% (14/15) in control group. There were 2 (11.2%) patients who developed meningitis in the LD group and 1 (5.6%) patient in the control group. One patient required endoscopic repair of skull base because of persistent cerebrospinal fluid leak in both groups, with the rates of 5.6% and 6.7%, respectively. There was no significant difference noted in each rate in both groups.Placement of LD may not be necessary for the management of low-flow postoperative cerebrospinal fluid leak after using endoscopic endonasal transsphenoidal approach to pituitary adenoma.

Sellar repair with autologous muscle and composite septal cartilage grafts for treatment of cerebrospinal fluid leakage following trans-sphenoidal pituitary surgery

Context:

Many reconstructive techniques have been proposed to prevent postoperative cerebrospinal fluid (CSF) leakage after trans-sphenoidal pituitary surgery. However, no total agreement has been reached to the best technique.

Aim:

Assessment of the efficacy of sellar repair with autologous muscle and composite septal cartilage grafts for treatment of intraoperative and delayed postoperative CSF leakage following trans-sphenoidal pituitary surgery without the use of postoperative external lumbar CSF drain.

Study Design:

This is a retrospective case series study, level IV evidence.

Materials and Methods

: Twenty three patients were involved in this study. Seventeen patients had intraoperative CSF leakage and were treated immediately by our technique. Six patients had postoperative CSF rhinorrhea and had delayed treatment with our technique after failure of conservative measures and external lumbar CSF drainage for more than three days. The technique involved intradural placement of autologous muscle graft supplemented with extradural composite septal cartilage graft, composed of a piece of the posterior cartilaginous septum with its covering mucoperichondrium on one side only to fit into the sellar defect as a double layer button.

Results:

CSF leak was of grade 1 in 6 patients (26.1%), grade 2 in 10 patients (43.5%) and grade 3 in 7 patients (30.4%). None of the patients in our study had postoperative CSF leak after the use of our technique during the follow up period (mean 24 ± 10.47 standard deviation months). None of the patients developed treatment-related complications. All the patients had well developed mucosal covering of the sellar defect after two months.

Conclusion:

Our technique of sellar repair by using autologous muscle and composite septal cartilage grafts is effective in treatment of intraoperative and delayed postoperative CSF leakage following trans-sphenoidal pituitary surgery without the use of postoperative external lumbar CSF drain even in the high-output CSF leaks.

Repair and prevention of cerebrospinal fluid leakage in transsphenoidal surgery: a sphenoid sinus mucosa technique

Cerebrospinal fluid (CSF) leakage is a common but sometimes serious complication after transsphenoidal surgery (TSS). To avoid this postsurgical complication, we usually repair the CSF leaking area using an autologous material, such as fat, fascia, or muscle graft and sometimes nasonasal septal flap. In this report, we propose a technique using a novel autologous material, sphenoid sinus mucosa (SSM), to repair intraoperative CSF leakage or prevent it postoperatively. On 26 February 2007, we introduced the technique of using SSM to repair or prevent CSF leakage in TSS. Until 30th of June 2014, we performed 500 TSSs for patients with pituitary or parasellar lesions. They were 195 men and 305 women with a mean age of 48.5 years (range, 5-85 years). We used SSM for patching or suturing the arachnoid laceration or dural defect, in lieu of fat or fascia harvested from abdomen or thigh, or made pedicle flap of SSM instead of nasonasal septal flap to cover the sellar floor. Comparing the previous 539 cases not using these techniques before 26 February 2007, intraoperative CSF leakage increased from 49 to 69.4% (p < 0.0001) due to more aggressive surgical technique, mainly related to more extensive approaches and lesion removals, but the rate of using fat was reduced significantly from 35.5 to 19.4% (p = 0.00021) in small or moderate CSF leaks during TSS without increasing the reoperation rate for postoperative CSF leaks (1.86 vs 1.2%, p = 0.45). The technique of using SSM to repair intraoperative CSF leaks or prevent them postoperatively in TSS was considered useful, effective, less invasive, easier for graft harvesting (same surgical field), and providing natural anatomical reconstruction, without potential donor site morbidity. We can recommend it as a standard method for CSF leaks repair and prevention in TSS.

Modified Graded Repair of Cerebrospinal Fluid Leaks in Endoscopic Endonasal Transsphenoidal Surgery

OBJECTIVE

Complete sellar floor reconstruction is critical to avoid postoperative cerebrospinal fluid (CSF) leakage during transsphenoidal surgery. Recently, the pedicled nasoseptal flap has undergone many modifications and eventually proved to be valuable and efficient. However, using these nasoseptal flaps in all patients who undergo transsphenoidal surgery, including those who had none or only minor CSF leakage, appears to be overly invasive and time-consuming.

METHODS

Patients undergoing endoscopic endonasal transsphenoidal tumor surgery within a 5 year-period were reviewed. Since 2009, we classified the intraoperative CSF leakage into grades from 0 to 3. Sellar floor reconstruction was tailored to each leak grade. We did not use any tissue grafts such as abdominal fat and did not include any procedures of CSF diversions such as lumbar drainage.

RESULTS

Among 200 cases in 188 patients (147 pituitary adenoma and 41 other pathologies), intraoperative CSF leakage was observed in 27.4% of 197 cases : 14.7% Grade 1, 4.6% Grade 2a, 3.0% Grade 2b, and 5.1% Grade 3. Postoperative CSF leakage was observed in none of the cases. Septal bone buttress was used for Grade 1 to 3 leakages instead of any other foreign materials. Pedicled nasoseptal flap was used for Grades 2b and 3 leakages. Unused septal bones and nasoseptal flaps were repositioned.

CONCLUSION

Modified classification of intraoperative CSF leaks and tailored repair technique in a multilayered fashion using an en-bloc harvested septal bone and vascularized nasoseptal flaps is an effective and reliable method for the prevention of postoperative CSF leaks.

The endoscopic hemi-transseptal approach to the sella turcica: operative technique and case-control study

Background The hemi-transeptal (Hemi-T) approach was developed to facilitate a binasal two-surgeon endoscopic approach for sellar tumors, with preservation of the nasoseptal flap and selective mobilization for reconstruction. Methods A retrospective case-control study was performed comparing the Hemi-T approach with previously used methods of sellar exposure and reconstruction. Outcome measures included operative time and postoperative nasal morbidity. Results A total of 23 patients underwent the Hemi-T approach versus 42 in whom traditional exposure was performed. Operative time was significantly shorter using the Hemi-T technique (152.6 ± 56.8 versus 205.2 ± 61.3 minutes; p = 0.001), as was the length of hospital stay (3.3 ± 1.9 versus 5.4 ± 3.6 days; p = 0.004). There was no difference in the rates of intraoperative or postoperative cerebrospinal fluid leak, cartilage necrosis, septal perforation, or mucosal adhesions. Conclusion The Hemi-T approach facilitates binasal two-surgeon access to the sella without compromise of the pedicle during the extended sphenoidotomies and tumor removal. Operative time and nasal morbidity is not increased, and iatrogenic injury to the nasal cavity is minimized when a flap is not required.

Pontine encephalocele and abnormalities of the posterior fossa following transclival endoscopic endonasal surgery

OBJECT

Transclival endoscopic endonasal surgery (EES) has recently been used for the treatment of posterior fossa tumors. The optimal method of reconstruction of large clival defects following EES has not been established.

METHODS

A morphometric analysis of the posterior fossa was performed in patients who underwent transclival EES to compare those with observed postoperative anatomical changes (study group) to 50 normal individuals (anatomical control group) and 41 matched transclival cases with preserved posterior fossa anatomy (case-control group) using the same parameters. Given the absence of clival bone following transclival EES, the authors used the line between the anterior commissure and the basion as an equivalent to the clival plane to evaluate the location of the pons. Four parameters were studied and compared in the two populations: the pontine location/displacement, the maximum anteroposterior (AP) diameter of the pons, the maximum AP diameter of the fourth ventricle, and the cervicomedullary angle (CMA). All measurements were performed on midsagittal 3-month postoperative MR images in the study group.

RESULTS

Among 103 posterior fossa tumors treated with transclival EES, 14 cases (13.6%) with postoperative posterior fossa anatomy changes were identified. The most significant change was anterior displacement of the pons (transclival pontine encephalocele) compared with the normal location in the anatomical control group (p < 0.0001). Other significant deformities were expansion of the AP diameter of the pons (p = 0.005), enlargement of the fourth ventricle (p = 0.001), and decrease in the CMA (p < 0.0001). All patients who developed these changes had undergone extensive resection of the clival bone (> 50% of the clivus) and dura. Nine (64.3%) of the 14 patients were overweight (body mass index [BMI] > 25 kg/m(2)). An association between BMI and the degree of pontine encephalocele was observed, but did not reach statistical significance. The use of a fat graft as part of the reconstruction technique following transclival EES with dural opening was the single significant factor that prevented pontine displacement (p = 0.02), associated with 91% lower odds of pontine encephalocele (OR = 0.09, 95% CI 0.01-0.77). The effect of fat graft reconstruction was more pronounced in overweight/obese individuals (p = 0.04) than in normal-weight patients (p = 0.52). Besides reconstruction technique, other noticeable findings were the tendency of younger adults to develop pontine encephalocele (p = 0.05) and the association of postoperative meningitis with the development of posterior fossa deformities (p = 0.05). One patient developed a transient, recurrent subjective diplopia; all others remained asymptomatic.

CONCLUSIONS

Significant changes in posterior fossa anatomy that have potential clinical implications have been observed following transclival transdural EES. These changes are more common in younger patients or those with meningitis and may be associated with BMI. The use of a fat graft combined with the vascularized nasoseptal flap appears to minimize the risk of pontine herniation following transclival EES with dural opening.

Acellular dermal allograft for sellar repair after transsphenoidal approach to pituitary adenomas

Objectives Our practice has transitioned from using fat autograft to acellular dermal matrix (AlloDerm, LifeCell Corp, Woodlands, Texas, USA). We present the largest series to our knowledge of AlloDerm for sellar floor repair after transsphenoidal approach to pituitary adenoma and compare rates of postoperative cerebrospinal fluid (CSF) leak with an earlier cohort of patients whose CSF leaks were repaired with fat autograft. Design This is a retrospective cohort study comparing sellar repair with fat autograft versus inlay Alloderm between the years 2003 and 2012. The primary end point was postoperative CSF leak. Results A total of 429 patients (368 primary; 83 revision operations) without intraoperative lumbar drainage were included. A total of 18 postoperative CSF leaks were observed (3.9%). Intraoperative CSF leak occurred in 160 cases (35.5%). Among this subset of patients with intraoperative CSF leak, 95 underwent repair with AlloDerm and 46 underwent repair with fat autograft, with postoperative CSF leak rates of 8.4% and 15.2%, respectively (p = 0.34, chi-square test); 19 patients underwent repair with other techniques or no repair at all, with postoperative leak rate of 0%. Conclusions AlloDerm is an effective alternative to fat autograft in cases of low-flow CSF leak following transsphenoidal resection of pituitary adenoma.

Useful 'sliding-lock-knot' technique for suturing dural patch to prevent cerebrospinal fluid leakage after extended transsphenoidal surgery

BACKGROUND

Postoperative cerebrospinal fluid (CSF) leakage is a major problematic complication after extended transsphenoidal surgery (TSS). Watertight closure of the sellar dura with a fascial patch graft is a method of choice for preventing CSF leakage; however, suturing and knotting in a deep and narrow operative field is technically challenging and time consuming. To present a simple and effective knotting technique named the 'sliding-lock-knot' technique, in which the knot can easily be slid to the suturing point and tied automatically using only a single string, without loosening.

METHODS

We use a 6-0 nylon suture and Mosquito forceps. At first, after putting a stitch, a single knot is made by hand out of the nasal cavity. Then the 'sliding-lock-knot' is made using a forceps as shown in the illustration. The knot slides deep into the operative field through the nostril and it is automatically tied only by pulling a string.

RESULTS

A 73-year-old woman presented with progressive visual deterioration. She had an intra-and suprasellar craniopharyngioma that was compressing the optic chiasm. She underwent an extended TSS, and the tumor was totally resected. The dural defect was closed with a fascial patch graft sutured on the dura using this technique, then covered with a vascularized mucoseptal flap. Neither CSF leakage nor meningitis was encountered during the postoperative period.

CONCLUSION

The 'sliding-lock-knot' technique is simple and useful for dural suturing in microscopic/endoscopic extended TSS. This technique is a helpful tool for preventing CSF leakage after this challenging surgical procedure.

Clinical efficacy of radiation-sterilized allografts for sellar reconstruction after transsphenoidal surgery

OBJECTIVE

The aim of this study was to assess the safety and efficacy of radiation-sterilized allografts of iliac bone and fascia lata from cadaver specimens to repair skull base defects after transsphenoidal surgery.

METHODS

Between May 2009 and January 2010, 31 consecutive patients underwent endonasal transsphenoidal surgery and all patients received sellar reconstruction using allografts following tumor removal. The allografts were obtained from the local tissue bank and harvested from cadaver donors. The specimens used in our approach were tensor fascia lata and the flat area of iliac bone. For preparation, allografts were treated with gamma irradiation after routine screening by culture, and then stored at -70℃.

RESULTS

The mean follow-up period after surgery was 12.6 months (range, 7.4-16 months). Overall, postoperative cerebrospinal fluid (CSF) leaks occurred in three patients (9.7%) and postoperative meningitis in one patient (3.2%). There was no definitive evidence of wound infection at the routine postoperative follow-up examination or during re-do surgery in three patients. Postoperative meningitis in one patient was improved with the use of antibiotics and prolonged CSF diversion.

CONCLUSION

We suggest that allograft materials can be a feasible alternative to autologous tissue grafts for sellar reconstruction following transsphenoidal surgery under selected circumstances such as no or little intraoperative CSF leaks.

Transnasal trans-sphenoidal endoscopic repair of CSF leak secondary to invasive pituitary tumours using a nasoseptal flap

Cerebrospinal fluid (CSF) leak following initiation of Dopamine agonist therapy for macroprolactinomas, although uncommon, has been described previously in the literature. Traditional management includes primary repair of the defect using either fat or fascia lata in conjunction with lumbar drain insertion. In this case series we outline two cases of CSF leak secondary to invasive pituitary tumour that were repaired successfully using a nasoseptal flap. We believe that this form of repair is effective and associated with minimal morbidity.

Low-grade CSF leaks in endoscopic trans-sphenoidal pituitary surgery: efficacy of a simple and fully synthetic repair with a hydrogel sealant

BACKGROUND

Intra-operative CSF leak during endoscopic trans-sphenoidal surgery is not uncommon. Surgical repair with a variety of autologous grafts, rigid buttresses and CSF diversion techniques that add time and complexity have been reported.

OBJECTIVE

To describe a simple and purely synthetic closure for low-grade CSF leaks following endoscopic trans-sphenoidal pituitary surgery.

METHODS

A retrospective review of all endoscopic trans-sphenoidal surgery undertaken for pituitary pathology between 2005 and 2010 was carried out. The grade of CSF leak and success of graded repair was noted. Patients with no CSF leak (grade 0) had gelatin sponge placed in the tumour cavity. In those with low-grade CSF leak through small arachnoid defects (grade 1), repair was carried out using gelatin sponge and hydrogel sealant overlay. CSF diversion was not employed for low-grade CSF leaks.

RESULTS

Of the 255 endoscopic trans-sphenoidal surgeries, 158 (62%) had no leak (grade 0) and 74 (29%) had a low-grade leak (grade 1). Repairs in all cases were of grade 0, and all but two cases of grade 1 CSF leak were successful at a mean follow-up of 29 months. The 2 (2.7%) post-operative CSF leaks were seen within 6 weeks of surgery. Both cases were related to bouts of sneezing and were repaired using further trans-sphenoidal surgery and/or lumbar CSF diversion.

CONCLUSIONS

A simple purely synthetic repair of low-grade CSF leaks is described. This repair is safe and comparable in efficacy whilst avoiding the morbidity related to more complex sellar reconstructions previously described.

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.

High-viscosity polymethylmethacrylate cement for endoscopic anterior cranial base reconstruction

Endoscopic endonasal transsphenoidal surgery (ETSS) is an effective, minimally invasive approach for the resection of anterior skull base tumors. Cerebrospinal leakage is a common complication, and repair of the anterior skull base defect with alloplastic materials has been used to minimize the risk of postoperative CSF rhinorrhea and meningitis. Injectable cements, such as low-viscosity polymethylmethacrylate (PMMA), are useful for cranial base reconstruction because they are easy to shape to the contour of the defect. These low-viscosity materials, however, are more susceptible to leakage into the nasal cavity prohibiting their use and are prone to cracking upon hardening. Cement extravasation not only obstructs the operator's view during placement, but it is also associated with significant local and systemic complications. High-viscosity (HV) PMMA-based cement and its specialized delivery system have recently been shown to be safe and effective in human applications. Moreover, its constant high viscosity significantly reduces cement leakage and its associated complications. The authors hypothesized that this type of cement would therefore be ideal for ETSS to repair anterior skull base defects. The authors report their experience using HV-PMMA to reconstruct the anterior skull base in 12 patients following ETSS. The unique puttylike consistency of this material is easy to work, malleable, does not leak into the nasal cavity, does not aspirate into suction tubing, and hardens without cracks in less than 10 minutes. None of the 12 patients suffered postoperative CSF leaks or infections more than 8 months, on average, after surgery. Although not necessary in all cases of ETSS, the authors conclude that HV-PMMA, if needed, may be an excellent choice for reconstructing the anterior skull base after ETSS. Further studies are needed to better assess the long-term outcomes of HV-PMMA cement and its use in repairing skull base defects after extended ETSS.

Pituitary tumors: our experience in the prevention of postoperative cerebrospinal fluid leaks after transsphenoidal surgery

The objective was to analyze the management of intraoperative CSF leaks in transsphenoidal surgeries to prevent postoperative cerebrospinal fluid (CSF) leaks. Sixty-three pituitary tumors were operated by transnasal approach. In presence of arachnoidal opening, a fat graft was placed into the sellar cavity, followed by collagen sponge layer and fibrin glue. The sphenoid sinus was also packed with fat graft and collagen sponge. An external CSF lumbar drainage was kept for 2-4 days. The variables analyzed were: intraoperative and postoperative CSF leaks, procedures, and related complications. The overall incidence of postoperative CSF leak was 1.5%. Twenty patients (31.7%) had intraoperative arachnoidal opening, 5% of whom had postoperative CSF leak. There were no reoperations because of CSF leak, and no secondary intrasellar arachnoidoceles. Mean follow-up was 3.6 years. The preventive treatment had good results and there were no complications related to the intervention strategy, encouraging us to continue performing this simple, effective, and inexpensive procedure.

Development of watertight and bioabsorbable synthetic dural substitutes

We have developed novel watertight and bioabsorbable synthetic dural substitutes. The substitutes were designed such that they had a three-layered structure, and each layer comprised a bioabsorbable copolymer prepared from L-lactide, glycolide, and epsilon-caprolactone. Various copolymers were synthesized, and appropriate compositions were selected for preparing the substitutes based on the results of leakage tests. Experimental substitutes that prevented the leakage of saline through the suture lines between the substitutes and dura mater were prepared. An in vitro study was performed in which the substitutes were sutured to porcine dura mater, and the amount of saline leakage was measured. It was demonstrated that leakage through the suture line could be completely suppressed by using the substitutes we developed along with favorable suturing techniques.

Expanded endonasal approach, a fully endoscopic transnasal approach for the resection of midline suprasellar craniopharyngiomas: a new classification based on the infundibulum

Object

Craniopharyngiomas are notoriously difficult to treat. Surgeons must weigh the risks of aggressive resection against the long-term challenges of recurrence. Because of their parasellar location, often extending well beyond the sella, these tumors challenge vision and pituitary and hypothalamic function. New techniques are needed to improve outcomes in patients with these tumors while decreasing treatment morbidity. An endoscopic expanded endonasal approach (EEA) is one such technique that warrants understanding and evaluation. The authors explain the techniques and approach used for the endoscopic endonasal resection of suprasellar craniopharyngiomas and introduce a tumor classification scheme.

Methods

The techniques and approach used for the endoscopic, endonasal resection of suprasellar craniopharyngiomas is explained, including the introduction of a tumor classification scheme. This scheme is helpful for understanding both the appropriate expanded approach as well as relevant involved anatomy.

Results

The classification scheme divides tumors according to their suprasellar extension: Type I is preinfundibular; Type II is transinfundibular (extending into the stalk); Type III is retroinfundibular, extending behind the gland and stalk, and has 2 subdivisions (IIIa, extending into the third ventricle; and IIIb, extending into the interpeduncular cistern); and Type IV is isolated to the third ventricle and/or optic recess and is not accessible via an endonasal approach.

Conclusions

The endoscopic EEA requires a thorough understanding of both sinus and skull base anatomy. Moreover, in its application for craniopharyngiomas, an understanding of tumor growth and extension with respect to the optic chiasm and infundibulum is critical to safely approach the lesion via an endonasal route.