Pituitary surgery

The degree of pneumatization and the position of septae in the sphenoid sinus are highly variable.
In the majority of cases the pituitary fossa will form a bulge in the posterior or posterosuperior region of the sphenoid and is easily identifiable with the operating endoscope.

1. Dr surbhi Patna medical college Pituitary tumors and surgery

2. SURGICAL ANATOMY

3. The degree of pneumatization and the position of septae in the sphenoid sinus are highly variable. In the majority of cases the pituitary fossa will form a bulge in the posterior or posterosuperior region of the sphenoid and is easily identifiable with the operating endoscope.

4. Historical aspect driven by the improvement in the optics. Sir Victor Horsley in 1906 – transfontal craniotomy Herman Schloffer first described a nasal approach 1907, Harvey Cushing - transseptal , transsphenoidal approach. 1960s the operating microscope the surgeon gets excellent illumination, 3D perception and two hands free for operating. This has been the mainstay of pituitary surgery until recently.

5. surgery in the late 1980s, and the first use in pituitary surgery rigid endoscopy

6. 12 per cent of all primary brain tumours. The majority are adenomas and are benign.

7. 50 per cent of adenomas are nonfunctioning and will present by virtue of their size as a space-occupying lesion.

8. PRESENTATION OF PITUITARY TUMOURS PROLACTINOMAS secondary amenorrhoea and galactorrhoea . dopamine controls prolactin secretion by inhibiting its release. bromocriptine cabergoline .

9. GROWTH HORMONE-SECRETING ADENOMAS acromegaly soft tissues and membranous derived bones coarsening of the facial features prognathism , hands and the feet increase lethargic and sweaty with macroglossia leading to sleep apnoea. The internal changes lead to hepato-splenomegaly , hypertension and increased risk of cardiomegaly .

10. insulin-like growth factor 1 (IGF1), Somatostatin Octreotide Surgery remains the treatment of choice Transsphenoidal surgery de-bulking of the tumour radiotherapy or somatostatin analogues

11. ADRENOCORTICOTROPHIC HORMONE-SECRETING ADENOMAS Cushing’s disease Ketoconazole Adenomas that produce ACTH are usually very active Small tumours can be difficult to locate Surgical adenomectomy inferior petrosal sinus sampling

12. ACTH levels to be assessed Pituitary adenomectomy

13. OTHER SECRETING PITUITARY TUMOURS Thyroid stimulating hormone (TSH) tumours that produce TSH, l uteinizing hormone (LH) and follicle stimulating hormone (FSH less than 1 per cent of pituitary tumours.

14. OTHER LESIONS IN THE PITUITARY FOSSA Rathke’s cleft cysts, craniopharyngiomas , meningiomas , chordomas and, rarely, aneurysms of the vessels of the circle of Willis. Secondary metastases from primary malignancies

15. MASS EFFECT PRESENTATION 50 per cent of adenomas will present with the hyper-secretion syndromes The classical presentation of a nonsecreting tumour is that of bitemporal hemianopia , headaches or hypopituitarism .

16. The nonsecreting tumours cannot be treated medically, and surgical regimens are the mainstay of treatment.

17. PREOPERATIVE MANAGEMENT establish whether the lesion is a nonfunctioning or a functioning hormone type baseline hormone levels suitability for medical treatment residual pituitary function needs to be established

18. Preoperative MR scanning computed tomography (CT) surgical navigation system image intensifier

19. Endoscopic technique PREPARATION decongestion of the nasal mucosa 10 mins before patient is anaesthetized in the reverse Trendelenburg position decongestion

20. STEP 1: SPHENOIDOTOMY

21. STEP 2: RESECTION OF POSTERIOR SEPTUM AND ROSTRUM good access to the sphenoid sinuses Killian’s type incision 1 cm anterior to the front wall of the sphenoid

22. The muco-perichondrial flap raised The bone of the posterior septum , sections preserved The rostrum of the sphenoid the muco-perichondrial flap on the side opposite to the incision is removed with the micro- debrider .

23. STEP 3: IDENTIFICATION OF LANDMARKS intrasphenoid sinus septae are highly variable The septae are reduced possible to identify the positions of the carotid arteries, the bulge of the pituitary fossa and possibly the optic nerves in the sphenoid.

24. Careful correlation of the preoperative radiology and the observed anatomy image intensifier or a surgical navigation system will be necessary in a small minority of cases

25. STEP 4: OPENING OF THE PITUITARY FOSSA

26. STEP 5: ADENOMECTOMY standard pituitary ring curettes. Gentle manipulation of the ring curettes A normal pituitary gland appears yellower than tumour tissue and is more adherent to the walls of the fossa .

27. positioning the tip of the endoscope inside the fossa . not to breach the diaphragm above the pituitary fossa Large tumours are resected by gently removing the inferior margin of the tumour

28. STEP 6: CLOSURE Small balls The dura of the anterior pituitary bony defect is repaired by placing a patch of bone Gelfoam over bony opening ribbon gauze

29. POST-OPERATIVE MANAGEMENT Neurological observation is recommended for the first 12–24 hours fluid balance charts and daily urea and electrolytes are monitored A regimen of steroid cover Antibiotic cover is necessary for 7 days.

30. COMPLICATIONS Bleeding Cerebrospinal fluid leak Infection Visual problems Endocrine problems

31. RADIOTHERAPY IN THE MANAGEMENT OF PITUITARY ADENOMA Radiotherapy can be an effective treatment for smaller adenomas and hyper-secretion syndromes, 2 to 5 years hyper-secretion syndrome Normal pituitary function will also decline with time long-term endocrine monitoring and hormone replacement

32. residual raised hormone secretion Unfit Nelson syndrome s/e:cva,hypopitutarism,on,bn,sec tumor Stereotactic radio-surgery in the form of the gamma knife or cyber knife improved control of hyper-section and a decreased reduction in residual pituitary function over conventional radiotherapy.

33. Thankyou