Endoscopic Endonasal Surgery for Adult Craniopharyngiomas

Case samples

 46 years old female with headache and diminution of vision. visual acuity was 6/12 both eyes, bitemporal hemianopia while fundus examination was normal. No hormonal abnormalities. MRI brain with contrast showed sellar & suprasellar mass of mixed consistency. Near Total Resection was achieved by transplanum transtuberculum transsellar approach. Post-operative transient DI which completely resolved 3 months after surgery and the visual disturbance improved postoperatively. (Fig. 2a, 2b).

Fig 2: (A) Preoperative Axial, Sagittal and coronal contrast-enhanced T1-weighted MR images of a case of craniopharyngioma with postfixed chiasma. (B) Postoperative Axial, Sagittal and coronal T1- weighted MR images of a case of craniopharyngioma with postfixed chiasma.

DISCUSSION

Owing it to an extremely variable growth pattern, craniopharyngiomas are deemed very difficult lesions to treat. Disputes about surgical management still exist. In recent years, "pure" endoscopic endonasal procedures aimed for the removal of craniopharyngiomas have begun to be carried out by numerous surgical centers around the world, already assured of endoscopic endonasal management of pituitary tumors.

Our study included 12 patients, (mean age 40 years).  Patients below 18 years were excluded which were consistent with other big series as (Park et al., 2017) ⁶ study which included 111 adult patients (95.6%) with a mean age of 43.8 years (range 14–74 years) and 5 children (4.4%) with a mean age of 15.6 year (range 14–17)  or (Cavallo et al., 2014) ⁷  study which included 83(81.6%) adult patients with a mean age of 50.36 years (range 18-83 years) and 20 children (19.4%) with a mean age of 10.1 years.  This was attributed to the fact it was our initial experience with this technique. The chief complaint in our study was visual disturbance in 10 cases (83.3%), endocrinopathy in 4 cases (33.3%), and headache in 9 cases (75%).  This is compatible with (Park et al., 2017)results where vision loss was the most common presenting symptom (83%) followed by headache (48%) and endocrinopathy (33%), while as (Cavallo et al., 2014) found that visual disturbances were present in 76.7% of patients followed by endocrinopathy in 56.6% of adult patients and hypothalamic symptoms in 24.3% of adult patients.

Prior to and after surgery, our patients received a comprehensive neuro-ophthalmological examination. Of the 10 patients with preoperative visual deficits 80% had full resolution of their visual impairment and 20% had partial resolution enhancement. However, no patient had deteriorating vision after surgery due to damage to the optic apparatus. These findings are consistent with those of(Parket al., 2017), where 76 %of the 89 patients with preoperative visual deficits reported improvement and 49 % reported postoperative normalization of visual deficits. Overall, postoperatively, a slight 7.3 % suffered visual degradation.On the other hand, (Cavallo et al., 2014) found that of the 103 patients, visual deficit improvement happened in 74.7 % ,deficiency normalization was accomplished in 5.1 %, while 17.7 % stayed the same, 2.5% had worsening of preoperative visual deficit, whereas in the Pittsburgh group study of the 16 patients, preoperatively, 14 patients had gradual visual defects, 6 (43 %) of which had full resolution of their visual defect and 7 (50 %) had enhancement but no full resolution and the deficit of one patient stayed stable.

The similarity of the results between different series shows the effectiveness of Endoscopic Endonasal Approach in chiasmal decompression. After the resection of craniopharyngiomas, panhypopituitarism and DI are especially common in terms of endocrinopathy.

However, in our study, none of the patients experienced postoperative panhypopituitarism, 4 of the patients had preoperative panhypopituitarism (33.3%) which improved postoperatively. 6 patients developed postoperative DI, 4 of them had it totally resolved, while only 2 patients (33.3%) suffered from permanent DI. Our results were relatively similar to those of (Gardner et al., 2008) ⁸ where, after surgery, only 2 patients experienced new-onset Panhypopituitarism (16.7%). Of 12 patients who experienced long-term follow-up, only 1 (8.3 %) endured permanent DI. In the postoperative era, four others developed temporary DI, which showed resolution during the last follow-up without further treatment. In other setting results was different for (Park et al., 2017) study as none of the 29 patients with preoperative panhypopituitarism reported recovery of endocrine function. Moreover, of the 36 patients with normal preoperative anterior pituitary function, 5 (14 %) experienced partial hypopituitarism and 16 (44%) experienced panhypopituitarism. Among the 98 patients without preoperative DI, 73 (74%) had no or transient DI and, 25 (25.5%) have postoperatively developed permanent DI. To add up, the results of Cavallo et al., 2014 and his colleagues found that there was deterioration in 43.8 % of cases that had normal anterior pituitary function, and among cases with preoperative panhypopituitarism, only 8% improved.

Also, preoperative DI remained unchanged in 100% of patients and the new start of DI was 48.1%.  The statistical difference between our study and the other number of studies might be due to our small sample size and the low incidence of preoperative panhypopituitarism.

However, the incidence of postoperative diabetes insipidus was almost the same and showed to be higher in patients with lesions involving the pituitary stalk (trans-infundibular type 2 lesions) according to (Kassam et al., 2008) ⁹ classification for craniopharyngioma. Craniopharyngiomas are very challenging tumors and the optimal modality of treatment remains controversial.  The best result in terms of recurrence-free survival has been correlated with intensive surgical therapy. However, complete surgical resection relies on the location of the tumor, size, and anatomical relation with neighboring vital neurovascular structures. In 9 patients (75%) we obtained Gross Total Resection (GTR) and in 3 patients (25%) we obtained Subtotal Resection (STR). Also, GTR achieved (75%) success rate of completely improved patients, while STR achieved only (25%) success rate of completely improved patients. The extent of total resection was acceptable when compared to other series in literature such as that of (Cavallo et al., 2014) where a higher GTR rate was achieved in supra-diaphragmatic retro-chiasmatic lesions (80%) and pre-chiasmatic lesions group (72.4%) in comparison with the pre & retrochiasmatic lesions (39.1%).  Moreover, safe and radical resection of supradiaphragmatic lesions depends heavily on the relation of the tumor to the infundibulum, a fact emphasized by (Gardner et al., 2008) study.  Preservation of endocrine function while attaining respectable extent of resection can be achieved in types I (preinfundibular) and III (retroinfundibular) tumor where the stalk can be isolated and potentially retained, while preserving function must be balanced towards recurrence risk in type II (transinfundibular) tumors. As regards the extent of resection, we found a significant statistical difference when our results were compared to a transcranial approach study on 20 patients by (Sun et al., 2017) ¹⁰ where GTR was achieved in 18 patients (90%) and only 2 patients (10%) had STR.  Yet, no significant statistical relation was found between GTR via transcranial approach and better postoperative endocrinological outcome. On the contrary in the transcranial literature, the incidence of new endocrinopathy varied from 24% to 66% for panhypopituitarism and 43% to 79% for DI, while in the endonasal sequence it is 18% to 67% for panhypopituitarism and 8% to 48% for permanent DI.  These distinctions can be clarified by better visualization of the infundibulum, pituitary stalk, and superior hypophyseal branches (Sua et al., 2011) ¹¹.

In our series, the characteristics of the lesions revealed that tumor consistency was mixed (solid-cystic) in 41.7% (5 patients), cystic in 58.3% (7 patients).  Calcifications of variable degree were found in 100% (12 patients) of cases.  However, we didn’t find any significant statistical correlation between tumor consistency and extent of resection.  Even though in some studies as (Park et al., 2017) or (Cavallo et al., 2014)the extent of resection was slightly higher in purely cystic lesions than in mixed lesions. In our series, CSF leakage in 4 patients (33.3 %) was the most frequent surgical complication. The most common medical complication showed to be diabetes insipidus in 6 patients (50%), disturbed conscious level (DCL) and seizures in 2 patients (16.7%). We found our results closely compatible with the literature as postoperative CSF leakage was the most frequent complications encountered by many authors e.g. (Yadav et al., 2015) ¹².  Primary endoscopic repair (in the same operation) was performed on all patients with CSF leakage. In our trial, none of the patients had a preoperative lumbar drain as elected by our surgeons. Finally, regarding efficacy outcomes, (66.7%) of patients had complete vision improvement, while (33.3%) had partial improvement, achieving 66.7% efficacy of resection operation. Regarding safety outcomes, (16.7%) had DCL and seizures, (50%) had DI, while (33.3%) had CSF rhinorrhea. GTR achieved (75%) success rate of completely improved patients, while STR achieved only (25%) success rate of completely improved patients.

CONCLUSION

To conclude, in terms of surgical result and tumor management, the Endoscopic Endonasal Approach (EEA) is an efficient surgical procedure for the removal of craniopharyngiomas. This small case series tends to promote the use of the endoscopic endonasl approach to have a greater degree of preservation of endocrine function and visual recovery, while obtaining a respectable extent of resections. However, for the precise assessment of the Endoscopic Endonasal approach, the expansion of the series, both in terms of number of patients and follow-up time, is critical.