Endovideomonitoring in Transsphenoidal Surgery of Pituitary Neoplasms
V.Yu. Cherebillo, V.R. Gofman, A.V. Polezhaev, V.A. Manukovsky
Chair of Neurosurgery, Medicomilitary Academy, Saint Petersburg, Russia
Surgical Technique
Examination of tissues, prolapsing into the dura incision, allowed to diagnose a tumor in 96% of cases. Neoplastic tissue looked like nodes with distinct borders against a background of intact pituitary tissue, which as a rule was
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Fig.7. Lateral fluoroscopy at the stage of adenoma removal with hypophyseal curettes. |
reddish-brown. As for nodes, they were yellowish-pink and had a harder structure (Fig.7).
We failed to visualize neoplasm during examination of an anterior surface of the pituitary body in 3-4% of cases. As a rule, it was typical of microadenomas, localized in posterior segments of the saddle. In this case, adenohypophysis
was dissected with a microscalpel for examination of its deeper-lying
segments. It resulted in revealing soft neoplastic tissue.
Yellowish-brown cystic fluid was aspirated at a stage of the saddle
puncture in 15% of cases. A panoramic visual examination of the sinus
after dura dissection revealed a cyst cavity. Introduction of the
endoscope's butt end into this cavity demonstrated a small quantity of
residual fluid. It was aspirated with a suction unit under endoscopic
control.
Magnification of 8-10 times, obtained in application of the endoscope, allowed
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Fig.8. Lateral fluoroscopy at the stage of removal of suprasellar fragments of pituitary adenoma with an ultrasound disintigrator. |
to differentiate between intact and pathologic tissues of the pituitary body practically in all cases.
After approaching the saddle and tumor cryodestruction of neoplastic tissue was carried out. Navigation of an active tip of a cryoprobe into pathologic tissue was assisted by application of an endoscope and an image converter see (Fig.8),
(Fig.9). It permitted to reduce bleeding.
Freezing, exposure and defreezing lasted about 10, 30-60 and 25 seconds respectively. A zone of cryonecrosis was dependent on a period of freezing. It corresponded to tumor dimensions, varying from 7 up to 15mm in diameter.
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Fig.9. Endoscopic differentiation of tumor and hypophysis. |
Trice-repeated successive freezing and defreezing was applied for achieving
100% necrosis of a calculated volume of neoplastic tissue. It was found
out, that there was no visual change of tissue after destruction; it
had the same color; no bleeding from tumor or its considerable
reduction were watched.
Then destructed tissue was removed with the help of an ultrasonic disintegrator and microsurgical technique. If a tumor was more than 1.5cm in diameter, its cryodestruction was fragmentary with subsequent removal of destructed tissues.
Removal of neoplastic tissue was performed with microforceps, a
microscopic suction unit, hypophyseal curettes of a different size, an
ultrasonic disintegrator. Endoscopic control and staged lateral
fluoroscopy were applied (Fig.10), (Fig.11).
Endosellar structures and peculiarities of relationship between a tumor and
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Fig.10. Introduction of a cryoprobe into neoplastic tissue: |
adenohypophysis were visualized rather well in removal of a neoplastic node in 31 cases (77.5%). When infra- and endosellar fragments were removed, endovideomonitoring and fluoroscopy allowed to examine suprasellar neoplastic segments and to perform their stage-by-stage removal. Direct visual control of neoplastic tissue, grasped by microforceps or aspirated by a suction unit, made it possible to avoid damage of intact tissue of the pituitary body, traction of adjacent nerves and vessels in the majority of interventions. Due to double control a surgeon had exact visual information on
position of microinstruments in relation to the saddle median line and a depth of
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Fig.11. Intraoperative lateral fluoroscopy, applied during adenoma cryodestruction:
3 - chiasmal cisterns, filled with oxygen; |
their introduction into its cavity. It was very important for
preserving integrity of the diaphragm and other eloquent anatomic
structures.
Endoscopic visualization,
permitting differentiation between neoplastic and intact tissue and
estimation of a character of relationships between adenoma and adjacent
structures, is a valuable source of information for a neurosurgeon, who
uses it for determination of tactics of tumor removal and an operation
volume. Such advantages of endoscopy, as good illumination, a
phenomenon of endomicroscopy and presence of a lateral view, make it
possible to estimate adenoma
borders intraoperatively and to determine localization and dimensions
of neoplastic fragments, which still demand removal. Striving for
greater efficacy of an operation and prevention of relapses in the
future, a surgeon tries to remove residues of adenoma
to the maximum. However, attempts to increase a volume of operation
result in a higher risk of damage of anatomic structures, adjacent to adenoma or characterized by tumor invasion.
Efficacy of intervention and hemostasis was estimated after adenoma removal (Fig.12). A turunda, soaked with hydrogen peroxide and inserted into the
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Fig.12. Endoscopic examination of the saddle cavity after tumor removal. |
sphenoid sinus for 2-3 minutes, was a sufficient means of hemostasis after tumor
removal. Sometimes staged endovideomonitoring allowed to detect
continuous bleeding from the saddle depth. This situation demanded
repeated tamponade of the sinus with the above
turunda; caprofer was used less frequently. An operation was completed
only when endoscopic examination did not reveal tumor residues and efficacy of hemostasis was confirmed.
Powder of kanamycinum or cephalosporine of the 2nd-4th generation (1.0g) was administered into the sphenoid sinus for prevention of infectious complications. Anterior tamponade according to Voyachek and applying four-tailed bandage were the last steps of intervention.
REFERENCES
-
Apuzzo M.L.J., Heifetz M.D., Weiss M.H., Kurze T. Neurosurgical endoscopy using the side-viewing telescope // J. Neurosurg.- 1977.- Vol. 46, N 2.- P. 398-400.
-
Cawley C.M., Tindall G.T. New techniques in managing sellar pathologies through modifications of the traditional transsphenoidal approach // Crit. Rev. Neurosurg.- 1997.- Vol. 7, N 2 .- P. 115-122.
-
Gamea A., Fathi M., EL-Guindy A. The use of the rigid endoscope in transsphenoidal pituitary surgery // J. Laryngol. Otol.- 1994.- Vol. 108, N 1.- P. 19-22.
-
Guiot G. Transsphenoidal spproach in surgical treatment of pituitary adenomas: general principles and indications in nonfunctioning adenoma. In: Kohler P.O., Ross G.T. Diagnosis and treatment of pituitary tumors. Amsterdam: Exepta Medica, International Congress Series N 303.- 1973.- P. 159-178.
-
Hardy J. Transsphenoidal hypophysectomy: neurosurgical techniques // J. Neurosurg.- 1971.- Vol. 34.- P. 582-594.
-
Heilman C.B., Shucart W.A., Rebeiz E.E. Endoscopic sphenoidotomy approach to the sella // Neurosurgery.- 1997.- Vol. 41, N 3.- P. 602- 607.
-
Jankowski R., Auque J., Simon C. et al. Endoscopic pituitary tumor surgery // Laryngoscope.- 1992.- Vol.102, N 2.- P. 198-202.
-
Jho H.D., Carrau R.L., Ko Y., Daly M.A. Endoscopic pituitary surgery: an early experience // Surg. Neurol.- 1997.- Vol. 47, N 3.- P. 213-223.
-
Rodziewicz G.S., Kelley R.T., Kellman R.M., Smith M.V. Transnasal endoscopic surgery of the pituitary gland: technical note // Neurosurgery.- 1996.- Vol. 39, N 1.- P. 189 - 193.
