[Results of surgical treatment of skull-base primary malignant tumors with intracranial invasion]

OBJECTIVE

Analysis of factors affecting life expectancy at patients with primary malignant tumors of anterior and middle parts of the skull base with intracranial invasion.

MATERIAL AND METHODS

139 patients (47 women and 92 men) with primary malignant tumors of the anterior and middle parts of the skull base with intracranial invasion (stage T4 according to TNM classification or stage C according to Kadish classification for estesioneuroblast ) were treated at the NMRCN Burdenko for the period from 2004 till 2018. The study was conducted by the method of total sampling. The observations are divided into 2 groups: primarily operated (group I) and repeatedly operated (group II).

RESULTS

The average age in both groups was 50 years. In most (64.7%) cases, the tumor affected the medial sections of the base of anterior and middle cranial fossae, and in 35.3% of cases it was localized laterally. All tumors were classified to T4 stage according to TNM classification or (9 olfactory neuroblastomas) to stage C according to Kadish classification.

DISCUSSION

The impact on life expectancy was largely provided by postoperative radiation therapy, the repeated nature of operation, and the presence of brain infiltration. In the total cohort of patients 5-year OS, 5-year RVS, 5-year-old IDF and 5-year LC were 50.7, 35, 54.2 and 36.4%, respectively. In group I, the medians OS and IDF were equal and amounted to 138.3 months. The median RVS was 43.8 months. 5-year OS equal to 63.6%, 5-year RVS - 40.8%, 5-year-IDF - 64.8%, 5-year LC was up to 65.7%. The survival rate in the analyzed cohort for 1, 2, 3 years was 81.4, 71.8 and 67.8%, respectively. In group II, the treatment results for the group of repeatedly treated patients were significantly worse. There were no cases of 5-year survival. The 1-, 2-, and 3-year survival rates were 59.3, 50.8 and 31.8%, respectively. The median OS was 27.1 months, IDF was 27.1 months, RVS was 18.2 months, and LC was 9.1 months.

CONCLUSION

The results and analysis of literature justify the feasibility of surgical treatment of patients with malignant tumors of craniofacial localization at T4 stage. The purpose of surgical intervention should be: elimination of the immediate threat to the patient's life due to edema and dislocation of the brain; the maximum possible removal of tumor tissue (cytoreduction); if possible, the elimination of the most significant symptoms for the patient (pain, nasal breathing disorders, cosmetic defect). If there are special reserves, it is obligatory to include radiation and chemotherapy in the treatment process.

Rate of rhinosinusitis and sinus surgery following a minimally destructive approach to endoscopic transsphenoidal hypophysectomy

BACKGROUND

There remains considerable variation in the extent of sinonasal preservation during the approach for endoscopic transsphenoidal hypophysectomy (TSH). We advocate for a minimally destructive approach utilizing turbinate lateralization, small posterior septectomy, no ethmoidectomy, and preservation of nasoseptal flap (NSF) pedicles bilaterally. Due to these factors, this approach may affect the rates of postoperative rhinosinusitis. The objective of this study is to define the rates of postoperative rhinosinusitis in patients undergoing this approach.

METHODS

Single institution, retrospective chart review of patients undergoing TSH from 2005 to 2018.

RESULTS

A total of 415 patients were identified and 14% developed an episode of postoperative rhinosinusitis within 3 months. These patients were significantly more likely to have had a history of recurrent acute or chronic rhinosinusitis. Most cases were sphenoethmoidal sinusitis managed with 1 to 2 courses of antibiotics. Of patients with postoperative rhinosinusitis, most did not undergo NSF. Average follow-up was 38 months. Six patients (1.4%) underwent post-TSH functional endoscopic sinus surgery (FESS). Average time from TSH to FESS was 26.3 months. Two of these patients had a history of prior chronic rhinosinusitis without polyposis. Two patients underwent revision TSH for recurrent tumor as the primary indication for surgery at time of FESS. Twenty-two-item Sino-Nasal Outcome Test (SNOT-22) scores generally increased immediately postoperatively, but frequently decreased below preoperative level by the time of last follow-up, regardless of whether patients developed rhinosinusitis.

CONCLUSION

Sinonasal preservation during TSH is associated with a low rate of postoperative rhinosinusitis requiring FESS and excellent long-term patient reported outcomes. We continue to advocate for sinonasal preservation during pituitary surgery.

A Novel Technique for Transpalatal Hypophysectomy

Objective  A novel technique is described for transpalatal hypophysectomy as an option for sellar region surgery using a microscope and/or endoscope. Technique  A straight submucosal tunnel (approximately 20 mm in diameter; 40-50 mm long-half the length required by conventional transsphenoidal hypophysectomy) is dissected in favorable alignment with the main tumor axis, providing a direct view that allows the surgeon to operate on large suprasellar tumors, even in cases of extra-axial expansion. Results  In a 25-year period, over 50 patients benefited from this surgery. Macroadenomas devoid of extra-axial expansions were totally excised (76.5%), otherwise, partially (23.5%). Forty-nine patients (98%) were extubated soon after surgery. Mean surgery duration was 3 hour 32 minute, with 2 days 6 hour before free feeding was restored. Postoperative hospitalization under neurosurgical care averaged 6 days 6 hour. Currently, patients undergoing the procedure do not require nasal tampons and can eat soft foods soon after recovery from anesthesia. Although two patients (3.9%) presented with oronasal fistulae postoperatively, no episodes of severe hemorrhage occurred during surgery and there were no cases of liquoric fistulae, visual impairment, panhypopituitarism, or severe syndrome of inappropriate antidiuretic hormone secretion. Conclusion  The new surgical approach is safe, effective, and well accepted by patients, who reported low levels of discomfort. Postsurgical complications or sequela are currently rare, but further operations should be performed using more appropriate materials, instruments, and equipment to allow comparisons with other techniques.

Audit of Complications in an Otolaryngology Led Skull-Base Surgical Practice

Objective  This study was aimed to classify and study complications of surgery of the cranial base, primarily from an otorhinolaryngology perspective. Design  This study was designed with consecutive cohort of skull base surgical cases. Setting  Tertiary referral academic center. Participants  Patients having skull-base surgery at a otorhinolaryngology based skull-base unit, from 2002 to 2015. Main Outcome Measures  Enumeration of complications is the main outcome of this study. Surgical procedures, categorized for complexity as per a unified system, are applicable to endoscopic and open procedures. Complications were categorized as per the British Association of Otolaryngologists coding of surgical complications. Complication classified as major if life-threatening, causing permanent disability, or compromising the result of surgery. Results  A total of 342 patients ( n  = 342) were operated; 13 patients' records were excluded due to < 6 months posttreatment follow-up. The study group constituted 204 anterior skull-base (endoscopic, 120; open/external, 84) and 125 lateral skull-base procedures. Complication rates noted to increase in both groups with increasing complexity of surgical intervention. Anterior skull-base surgery (total complications, 11%; major, 3%; death, 0.5%) noted to have significantly less surgical complications than lateral skull-base surgery (total complications, 33%; major, 15%; death, 1.6%; p  < 0.001). Among the anterior procedures no significant difference noted among endoscopic and external approaches when compared across similar surgical complexity. Conclusion  Despite improvement in surgical and perioperative care, the overall major complication rate in a contemporary otolaryngology led, primarily extradural, skull-base practice is noted at 8%. Perioperative mortality, though rare, was encountered in 1%. A standard method for categorization of surgical complexity and the grade of complications as reported here is recommended.

Pedicle Flaps Contribute to Endoscopic Skull-Base Surgery and Facial Soft-Tissue Repair: The Diuturnity of Johannes Fredericus Samuel Esser (1877-1946)

Pedicle flaps based on the external maxillary (facial) artery were introduced during the World War I, precisely a century ago. Today they remain effective tools in facial soft-tissue repair. Recently, pedicle flaps based on the internal maxillary (sphenopalatine) artery have been chosen to reliably close dural defects after endoscopic skull-base surgery. Pedicle flaps, "biologic" to the extent they are based on a defined arterial blood supply, are the lasting contributions-the diuturnity-of Johannes ("Jan") Fredericus Samuel Esser (1877-1946) of Leiden, Holland, and Chicago (IL).

A Clinical Pilot Study of a Modular Video-CT Augmentation System for Image-Guided Skull Base Surgery

Augmentation of endoscopic video with preoperative or intraoperative image data [e.g., planning data and/or anatomical segmentations defined in computed tomography (CT) and magnetic resonance (MR)], can improve navigation, spatial orientation, confidence, and tissue resection in skull base surgery, especially with respect to critical neurovascular structures that may be difficult to visualize in the video scene. This paper presents the engineering and evaluation of a video augmentation system for endoscopic skull base surgery translated to use in a clinical study. Extension of previous research yielded a practical system with a modular design that can be applied to other endoscopic surgeries, including orthopedic, abdominal, and thoracic procedures. A clinical pilot study is underway to assess feasibility and benefit to surgical performance by overlaying CT or MR planning data in real-time, high-definition endoscopic video. Preoperative planning included segmentation of the carotid arteries, optic nerves, and surgical target volume (e.g., tumor). An automated camera calibration process was developed that demonstrates mean re-projection accuracy (0.7±0.3) pixels and mean target registration error of (2.3±1.5)mm. An IRB-approved clinical study involving fifteen patients undergoing skull base tumor surgery is underway in which each surgery includes the experimental video-CT system deployed in parallel to the standard-of-care (un-augmented) video display. Questionnaires distributed to one neurosurgeon and two otolaryngologists are used to assess primary outcome measures regarding the benefit to surgical confidence in localizing critical structures and targets by means of video overlay during surgical approach, resection, and reconstruction.

High-Accuracy 3D Image-Based Registration of Endoscopic Video to C-Arm Cone-Beam CT for Image-Guided Skull Base Surgery

Registration of endoscopic video to preoperative CT facilitates high-precision surgery of the head, neck, and skull-base. Conventional video-CT registration is limited by the accuracy of the tracker and does not use the underlying video or CT image data. A new image-based video registration method has been developed to overcome the limitations of conventional tracker-based registration. This method adds to a navigation system based on intraoperative C-arm cone-beam CT (CBCT) that reflects anatomical change, in turn providing high-accuracy registration of video to the surgical scene. The resulting registration enables visualization of the CBCT and planning data within the endoscopic video. The system incorporates a mobile C-arm for high-performance CBCT, integrated with an optical tracking system, video endoscopy, deformable registration of preoperative CT with intraoperative CBCT, and 3D visualization. As in the tracker-based approach, in the image-based video-CBCT registration the endoscope is localized using an optical tracking system that provides a quick initialization followed by a direct 3D image-based registration of the video to the CBCT. In this way, the system achieves video-CBCT registration that is both fast and accurate. Application in skull-base surgery demonstrates overlay of critical structures (e.g., carotid arteries and optic nerves) and surgical target volumes with sub-mm accuracy. Phantom and cadaver experiments show consistent improvement in target registration error (TRE) in video overlay over conventional tracker-based registration - e.g., 0.92 mm versus 1.82 mm for image-based and tracker-based registration, respectively. The proposed method represents a two-fold advance-first, through registration of video to up-to-date intraoperative CBCT (overcoming limitations associated with navigation with respect to preoperative CT), and second, through direct 3D image-based video-CBCT registration, which together provide more confident visualization of target and normal tissues within up-to-date images and improved targeting precision.