A CLINICAL EXPERIENCE IN ENDOSCOPIC ENDONASAL TRANSSPHENOIDAL HYPOPHYSECTOMY IN SKULL BASE CENTER OF BASRAH

Introduction ndoscopic Endo-nasal TransSphenoidal (EETS) technique has gained increased satisfactoriness for elimination of sellar and para-sellar tumors1 . Griffith2 first described the endonasal approach for removal of pituitary lesions in 1987 as a modification of Hirsch’s original approach. Jho et al3 have subsequently popularized the technique. Feasibility of technique with good surgical and functional outcome has made it popular among ENT and neurosurgeons over the last two decades4 . Preference of EETS over the conventional trans-septal and sub-labial approachs resulted from improved visualization and illumination of operative fields and low incidence of related morbidity5 . Availability of wide angled scopes and high definition cameras allow much better control during surgery and hence significantly better results6 . This technique has been developed under minimally invasive surgical strategies for patients with pituitary tumors, which eliminates the use of transsphenoid retraction7,8 . The endoscope represents one of the latest EEndoscopic endonasal transsphenoidal hypophysectomy Mustafa Haseeb Atiyah & Ahmed M Al-Abbasi Bas J Surg,June, 27, 2021 13 innovations because of its ability to have a wider panoramic view9 through a narrow surgical corridor and its ability to provide angled ‘close up view’ to detect eventual tumor remnants10 . Patients and methods A prospective study was carried out from August 2017 to June 2019 at Basrah skull base center in Al-Sader Teaching Hospital which included 50 patients as shown in table I. A detailed history, clinical examination and investigations were performed according to a predesigned questionnaire to inquire about information related to age, gender, residence, occupation, and symptomatology. All patients scheduled for pituitary surgery underwent radiological evaluation (CT scan of nose and PNS and MRI of brain), endocrine assessment by endocrinologist, visual field tests pre- and postoperatively by ophthalmologist. Preoperative and postoperative nasal endoscopic examination was also a part of routine assessment done by ENT surgeon. All patient were evaluated by neurosurgeon for full neurological examination pre and postoperatively. Endoscopic endonasal transsphenoidal surgery took place under general orotracheal anesthesia, the oropharyngeal region being well packed with a gauze roll to prevent postoperative blood and fluid aspiration. Intraoperative antibiotic treatment was with an intravenous third generation cephalosporin. The patient was positioned to be supine with slight elevation of the head. The surgery has four stages (nasal stage, sphenoid stage and reconstruction done by otolaryngologist, while sellar stage by neurosurgeon). Surgery commenced with endoscopic identification of the middle and superior turbinates. The middle turbinate and the sphenoid ostium lead the surgeon to the sphenoid sinus. Enlargement of the sphenoid ostium was the next step followed by identification of the sphenoid sinus. The same procedure was performed through the other nostril, that is, a ‘‘binostril approach’’. After enlargement of both sphenoid ostia and removal of sphenoid septum or septa, identification of the structures in the sella region was done. The neurosurgeon now takes the work and completes the sellar stage with tumor removal. After complete removal of tumor, reconstruction stage done by otolaryngologist by various types depends on the state of surgical defect. Sphenoid pack and bilateral anterior nasal pack was put, patient monitored in ICU for the first 24hrs. Nasal pack removed after 48 hrs , and sphenoid pack after 5 days. Analgesia and antibiotics were routinely prescribed for the patients postoperatively. Table I. Demographic characteristics Gender Total Male Female Frequency % Frequency % Frequency % 1-10 years 0 0 1 2 % 1 2 % 11-20 years 6 12 % 1 2% 7 14 % 21-30 years 1 2% 10 20% 11 22 % 31-40 years 6 12 % 7 14% 13 26 % 41-50 years 5 10% 9 18% 14 28 % above 50 years 3 6% 1 2% 4 8 % Total 21 42 % 29 58% 50 100 %Endoscopic endonasal transsphenoidal hypophysectomy Mustafa Haseeb Atiyah & Ahmed M Al-Abbasi Bas J Surg,June, 27, 2021 14 Results The most common presenting symptoms for the patients enrolled in this study was; headache which was present in 80% (40 patients), while infertility and hemiparesis were the least symptoms 2% for each (one patient) as shown in figure 1. Figure 1: Clinical presentation of patients Tables II & III shows the diagnostic characteristics and the location of pituitary tumor detected by MRI preoperatively. Forty six patients (92%) diagnosed as pituitary adenomas. One patient have Rathke’s cyst and another one have meningioma. We operate on 80% (40 patients) virgin cases and achieved 82% complete surgical resection of tumor in all the cases. Table II: The MRI characteristics of the tumors Table III: The location of the tumors Different methods with various materials for skull base repair was used as showed in table IV. The most common method used is underlay multilayers which used in 62% (31 patients), while in 10% posterior based middle turbinate flap were used in reconstruction. The mean duration period of follow up was 3 to 12 months. We found Type Frequency % Pituitary adenoma 42 84 % Pituitary adenoma with apoplexy 4 8 % Craniopharyngiomas 2 4 % Rathke’s cyst 1 2 % Meningioma 1 2 % Total 50 100 % Location of the tumor Frequency % Sella 11 22 % Sellar with suprasellar extension 35 70 % Sellar with parasellar extension 3 6 % Sellar with supra- and parasellar extension 1 2 % Total 50 100 % 80 % 56% 38% 10% 6% 6% 2% 2% 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% Presenting symptoms Endoscopic endonasal transsphenoidal hypophysectomy Mustafa Haseeb Atiyah & Ahmed M Al-Abbasi Bas J Surg,June, 27, 2021 15 that 3 patients (6%) developed significant epistaxis, 3 patients (6%) CSF rhinorrhea, and unfortunately 2 patients (4%) died postoperatively. Table IV: Types of repair Discussion Pituitary tumors are the most commonly encountered intracranial neoplasms, while most recent series estimate the prevalence of clinically apparent pituitary lesions to comprise approximately 10-15 % of all intracranial lesions11 . Many surgical approaches to sella are used, but the endoscopic trans-sphenoidal approach become a standard procedure to access sella and pituitary region4,12 . Traditionally, pituitary surgery comes under the realm of neurosurgeon but introduction of EETS approach to sella has made Otorhinolaryngologist an active partner in surgical management10 . The most common presenting symptoms for patient with pituitary tumors in our study was headache in 80% (40 patients), followed by visual disturbance 56% (28 patients), and the least on was infertility 2% (one patient). This results is comparable with Hanuman et al13 , Yildirim et al14 and not match with Singh et al15 in which visual disturbance is the most common presenting symptoms followed by headache in his review. The acceptable explanation for occurrence of headache and visual disturbance in pituitary tumors is, they are mostly due to mass effect of tumor to surrounding structures. In our study, 82% (41 patients) underwent complete tumor resection while 18% (9 patients) were incomplete. This may be due to learning curve as in early cases, with improve surgical skills and with increasing experience the tumor resection become complete and inability to access tumor in those patients has wide intracranial extensions. These results are encouraging and much higher than those with Jho et al16 (70%), Singh et al15 (64%), Hanuman et al13 (64%), and nearly same as S Kumar et al17 (86%), but less than Varshney et al 10 (90%), and Dehdashti et al 18 (90%) as they used image guided endoscopy (neuronavigation) during the procedure which improve visualization and decrease complications. Different types of reconstruction for skull base surgical defect were used. The most common type is multilayers repair in 62% (31 patients), multilayer with septal flap and fat used in 28% (14 patients) when large defect of sella seen after tumor removed and CSF leak occur. In 5 patients (10%) we use posterior based middle turbinate flap for repair. The complication rate in this study is comparable to previous studies indicating low complication rate for EETS which make it as safe procedure in comparable to other approaches. The most common encountered one was CSF leak found in 6% (3 patients). These results are lower than other study of Kumar et al17 (11%), Hanuman et al13 (12%), Singh et al15 (8%), and higher than Varshney et al10 (3.5%), Jho et al16 (4%), and Cappabianca et al19 (2%). These results are unrelated to type of closure of skull base defect. Among these three patients, one patient needed another surgical intervention to seal the leak, the remaining resolved on conservative Repair types Frequency Percentage Underlay multilayers 31 62 % Underlay multilayers with septal flap and fat 14 28 % Middle turbinate flap 5 10% Total 50 100%Endoscopic endonasal transsphenoidal hypophysectomy Mustafa Haseeb Atiyah & Ahmed M Al-Abbasi Bas J Surg,June, 27, 2021 16 measures. Epistaxis is also encountered in 6% (3 patients), this results match with Cappabianca et al19, Cavallo et al20, but more than Kumar et al17(0.7%). Diabetes incipidus found in 2% (one patient). this result is comparable to Dehdashti et al18 , Charalampaki et al21 and much lower than Varshney et al10(7%) and Singh et al15(8%). The mortality rate was 4% (2 patients) in our study, they died during the first week postoperatively. First one died in the 3rd postoperative day in ICU due to sever pneumocephalus, second one died in 5th postoperative day due to meningitis. These results are higher than other studies, Dehdashti et al18 , Charalampaki et al21 and Varshney et al10 , which showed no mortality in their studies. Conclusion: The frequency of pituitary tumors varies greatly according to age and gender. The various tumor types have their peak occurrence in distinctly different age groups and differ greatly in their femaleto-male ratios. The EETH is safe, effective and has a low complication rate. Postoperative assessment showed encouraging symptomatic improvement and significant hormonal normalization.