Diabetes Insipidus Following Transsphenoidal Pituitary Adenomectomy

Background: Transsphenoidal pituitary adenomectomy initiated from 1907 (Schloffer).At that time,because of poor lighting, deep operative site, poor unfolding, difficult hemostasis, incidental leakage of cerebrospinal fluid and hard controlling intracranial infection,for a long time,the approach had not been used widely.Till 1960's,Hardy used operating microscope for transsphenoidal pituitary adenomectomy.By dint of its magnification and lighting advantages,operating unfolding took on a new look.From 1970's,along with the development of image diagnostics and radioimmunity-endocrine diagnostics,early diagnosis even supraearly diagnosis of pituitary adenoma especially microadenoma became possible.Then pituitary adenomectomy was no longer satisfied with optic nerve decompression and so on,but trying radical cure of functional endocrine disorder.Accompanying the improvement of operating microscope , microinstrument and X-ray registration device,transsphenoidal pituitary adenomectomy developed unprecedentedly.The approach possesses the advantages of tiny damage, good operative effect, safety, time saving, low complication and low fatality .Now it is accepted by more and more neurosurgeons.Besides strict mastering operating indication, well knowing relative opography, mastering operating technique,operator should deeply know possible complication and master preventive and curative measures,to lower the possibility of the operative complication and boost the operating effect as well as safety.Diabetes insipidus is one of the most frequent complications of transsphenoidal pituitary adenomectomy.Objective: 776 postoperative patients who underwent transsphenoidal microsurgery for pituitary adenoma were selected from Shandong Province Hospital ,from 1999 to 2006.Upon retrospective analysis on the clinical data,we want to analyze the correlative factors influencing the incidence of postoperative diabetes insipidus(DI). Including the sex of the patient,the size of the adenoma,the type of the adenoma and the excision form of the operation. Material and methods:1.Material The clinical data of 776 postoperative patients from Shandong Province Hospital ,from 1999 to 2006,who underwent transsphenoidal microsurgery for pituitary adenoma were retrospectively analyzed.Including 352 male ones and 424 female ones. 14～72 years old.Mean age was 36 ± 12 years old.88 ones of microadenomas(diameter of the adenoma≤1cm),492 ones of macroadenomas(1cm3cm).326 PRL secreting adenomas,154 GH secreting adenomas,20 ACTH secreting adenomas, 203 nonfunctional adenomas, 71 mixed secreting adenomas and 2 TSH secreting adenomas. 582 ones of total resection and 194 ones of subtotal ectomy.All the patients were given head CT or MRI exam before operation.2.Methods All the patients were given transsphenoidal microsurgery for pituitary adenoma.Gave urethral catheters before operation.Gave fluid replacement by 2500～3000ml on the day after operation.After operation,recorded every hour's urine volume,and gave dynamic exam on electrolyte, urine specific gravity and blood , urine osmotic pressure.Commonly believed,if postoperative urine specific gravity <1.005,urine volume >4000ml/d or urine volume >200ml/h, urine osmotic pressure(Uosm)<200mmol/L,DI is diagnosed.The measurement data is expressed by x±SD.The comparison of the numeration data is analyzed by x~2. All the clinical data is analyzed by SPSS11.5 software.When P<0.05, there is statistical significance.Results: Postoperative DI occurred in 247 cases,which incidence was 31.8%.As following:①141 male ones(40.1%),106 female ones (25.0%),the incidence:male >female. Analyzed by SPSS software, x~2 = 30.688,P<0.05,there is statistical significance (Attached table 1).②41 giant adenomas(20.9%),166 macroadenomas (33.7%),40 microadenomas (45.5%),the incidence:microadenomas>macroadenomas>giant adenomas, x~2 = 20.211, P<0.05,there is statistical significance( Attached table 2).(3)114 PRL secreting adenomas(35.0%),51 GH secreting adenomas (33.1%),3 ACTH secreting adenomas(15.0%),62 nonfunctional adenomas (30.5%),15 mixed secreting adenomas(21.1%),2 TSH secreting adenomas(100.0%),the incidence:TSH adenomas>PRL adenomas>GH adenomas>nonfunctional adenomas>mixed secreting adenomas>ACTH secreting adenomas, x~2 = 15.599,P<0.05,there is statistical significance ( Attached table 3).(4)215 ones of total resection(36.9%),32 ones of subtotal ectomy(16.5%),the incidence:total resection>subtotal ectomy, x~2 = 37.885,P<0.05,there is statistical significance ( Attached table 4).DI mostly occurred in 24h after operation.A few tardus ones occurred 48h later.All were given drug treatment.The transient DI lasted 4h～8d,most of which were 2d～5d.16 cases were persistent DI. Urine volume ranged from 200ml/h to 800ml/h when DI occurred. Accompany the urine volume increasing,the colour of the urine turned light,even to colorless water like .The urine specific gravity and Uosm turned lower. Urine volumes were 4000ml～10800ml per day.Conclusion:① In patients who underwent transsphenoidal microsurgery,the incidence of postoperative DI was closely correlated with the patients' sexes:male>female;②In patients who underwent transsphenoidal microsurgery,the incidence of postoperative DI was closely correlated with the adenoma size: microadenomas> macroadenomas>giant adenomas;③In patients who underwent transsphenoidal microsurgery,the incidence of postoperative DI was closely correlated with the adenoma type:TSH secreting adenomas>PRL secreting adenomas>GH secreting adenomas> nonfunctional adenomas>mixed secreting adenomas>ACTH secreting adenomas;④ In patients who underwent transsphenoidal microsurgery,the incidence of postoperative DI was closely correlated with the excision form of the operation: total resection> subtotal ectomy.