*8.2.4 Sellar reconstruction*

At the end of the procedure, especially in case of an intraoperative CSF leak, sellar repair is mandatory. Different methods of repair techniques are used (intra and/ or extradural closure of the sella and packing of the sellar cavity with or without packing of the sphenoid sinus), based on the size of osteo-dural defect and of the space created following removal of the tumor inside the sella [88]. A number of dural substitute, tissue sealant and nasal packing are now available to secure the sellar reconstructions in place.

The aim of such a repair is to guarantee a watertight closure reducing the chance of CSF leak, reduce the dead space and prevent the descent of the chiasm into the sellar cavity. Nevertheless, overpacking has to be avoided to prevent compression of the optic system. Lumbar drainage is currently avoided, except in case of a minimal, unexpected post-operative CSF leak occurs. The endoscope is removed gradually, and the middle turbinate is gently put back in a medial direction. Packing of the nasal cavity is not used by most of the surgeons, though there are absorbable and non-absorbable packing are available.

#### **8.3 Advantages**

Transsphenoidal endoscopic resection of pituitary tumor brings a number of advantages to the patient like less nasal trauma, no nasal packing, less post-operative pain and usually quick recovery. The surgeon enjoys some advantages too, like wider and closer view of the surgical target area, recording of the operation for training and studying purposes for future improvement and more interdisciplinary cooperation etc. [89–91].

#### **8.4 Complications**

The study by Ciric et al. [92] which is regarded as the benchmark transsphenoidal surgery complication questionnaire pertaining to perioperative complications reported major morbidity in 1–2% of cases and postoperative CSF leaks in 3.9% of cases. The most experienced surgeons had better results with lower complication rates [93].

Lobatto et al. reported the postoperative incidence rates of CSF leaks between 1.4 and 16.9% in their systematic review where the higher body mass index (BMI) and younger age were risk factors for postoperative CSF leaks [94]. The reported incidence of DI ranges from 0.3–45% and is variable in part because of inconsistent definitions [95]. Two experienced pituitary groups who used accepted definitions for DI and whose surgical experience predominantly focused on endoscopic resection of pituitary adenomas have recently published their postoperative DI rates with fairly comparable results [96, 97]. In 178 and 271 patients respectively, both studies

reported a DI incidence rate of 26% and 16.6% with only 10% and 4% progressing to permanent DI [96, 97].

While hypernatremia can lead to severe morbidity in the perioperative phase, delayed hyponatremia is the most common cause of unplanned readmission following pituitary tumor surgery [98]. Most delayed hyponatremia is a secondary consequence of inappropriate release of antidiuretic hormone (SIADH) and usually occurs between post-operative day 4 and 7 with a reported incidence of 3.6% to 19.8% [99–101].

Dysfunction of the hypothalamic–pituitary axis (HPA) remains a recognized clinical problem. The most life threatening of these problems is adrenal insufficiency with contemporary cases series reporting rates between 3% and 21% [102].

Excessive removal of nasal septum can result in loss of nasal structural support, resulting in external nasal deformity. This risk can be increased when extended approaches requiring nasal septal flap reconstruction are employed [103, 104]. Removal of significant posterior-superior portions of the nasal septum, its mucosa, and the adjacent superior and middle turbinate mucosa (structures which make up the olfactory cleft) can result in hyposmia, or worse, anosmia. Therefore, an adequate surgical corridor needs to be carefully created towards the sellar region while trying to preserve the above structures specially when nasoseptal flap is harvested [105, 106].

Injury to the ICA during sellar exposure or removal of the tumor is rare with reported incidence between 0.2 to 0.4% and is associated with significant morbidity [107]. The iatrogenic injury can result in severe stroke, disability or death [108]. Significant epistaxis requiring additional intervention can occur in the range of 3% of cases [109, 110].

Ciric et al. reported from the self –reported questionnaire survey that the mean operative mortality for all three groups was 0.9% [92]. Agam et al. recently (2019)


#### **Table 3.** *Complications of pituitary surgery.*

reported only one case of mortality among 1153 cases, which is 0.1% perioperative death in their series [111].

Agam et al. reported patients with visual deficits and tumors which invades any surrounding structures are at higher risk of complication, is likely a caveat of more severe underlying disease [111]. Revision surgeries for prior transsphenoidal surgery, craniotomy and radiosurgery were also at higher risk for complications, likely because of fibrosis, adhesions and scarring that make the surgical environment more difficult (**Table 3**) [112].
