Preliminary Study Of Hydrostatic Pressure Of Sacral Cyst And Evaluation Of Efficacy Of Microsurgery

Part Ⅰ Study on the relationship between hydrostatic pressure and postural changes in sacral cyst cystsObjective:At present,the pathological mechanism of sacral cyst is not clear,and most people believe that its symptoms are related to changes in intracapsular pressure,but there is a lack of objective evidence;Delayed development of myelographic cysts may partly reflect the presence of a one-way valve mechanism,and elevated intracapsular pressure may be responsible for a range of symptoms.This study aims to explore the relationship between intracapsular pressure and body position by clinically monitoring changes in intracystic pressure in sacral cysts.Further verification of the pathological mechanism from the perspective of cyst pressure.Methods:From January 2018 to March 2022,10 clinical cases of sacral cyst in the Second Hospital of Shanxi Medical University were collected,the sacral canal was incised,the cyst was exposed,and the intracranial pressure probe was inserted into the sac to seal the sac wall to prevent the loss of fluid in the sac.Adjust the angle of the operating table separately,the head of the bed is 15 degrees,30 degrees high,and the head of the bed is 15 degrees lower,and the pressure change in the capsule is monitored.After the operation,suture the muscle to close the sacral canal,place the intracranial pressure probe into the sacral canal,and repeat the above operation again.Observe whether the pressure value changes with position,and the magnitude of the change.Results:Direct observation during surgery showed that all 10 patients had leakage and cerebrospinal fluid outflow;After changing the position,the hydrostatic pressure value in the capsule changes.The intracapsular pressure at 30 degrees of bedhead height was 10.6-12.4 mm Hg,the intracapsular pressure of 15 degrees of bedhead height was 9.7-11.2 mm Hg,the intracapsular pressure of horizontal position was 8.9-9.5 mm Hg,and the intracapsular pressure of 15 degrees lower at the head of the bed was 3.1-5.6 mm Hg.After the operation,the cyst disappeared,and the pressure in the sacral canal was measured,and the pressure in the sacral canal at 30 degrees at the head of the bed was 0.1-0.8 mm Hg,the pressure in the sacral canal at 15 degrees at the head of the bed was 0.1-0.6 mm Hg,the pressure in the horizontal sacral canal was 0.1-0.5 mm Hg,and the pressure in the sacral canal at 15 degrees lower at the head of the bed was 0.1-0.5 mm Hg.The intracapsular pressure value fluctuated from 3.1 to 12.4 mm Hg in different positions.Postoperative intrasacral pressure fluctuates from 0.1 to 0.8 mm Hg in different positions.Conclusion:In 10 patients,cerebrospinal fluid flowed out of the leakage during surgery,indicating that the sacral cyst communicated with the subarachnoid space;After changing the position,the intracapsular pressure value changed and stabilized.The side confirms the existence of a one-way flap mechanism;The insignificant change in intrasacral pressure value indicates that the change in position has limited effect on intrasacral pressure.Preoperative intracapsular pressure tends to increase with the increase of the head of the bed,similar to the pressure in the subarachnoid space of the spinal cord,arterial beat,changing position,severe cough,and Valsalva movements.The author believes that the change of position can make the CSF hydrostatic pressure increase suddenly,the increase in hydrostatic pressure leads to the opening of the one-way valve,in this process,the pressure difference between the inside and outside the capsule also helps the one-way valve opening,CSF leaks into the space around the normal nerve root through the communication hole,resulting in increased intracapsular pressure,cyst enlargement,gradually compressing or traction the nerve root,resulting in organic lesions of the affected nerve root;The pathological mechanism of sacral cysts may be the result of a combination of factors,of which stressors are indispensable.。Part Ⅱ Microsurgical treatment and efficacy evaluation of sacral cystObjective:To explore the clinical efficacy of microsurgery in the treatment of sacral cysts,and further clarify the surgical treatment strategy of this disease.Methods:In this study,patients with symptomatic sacral cyst who presented to the Department of Neurosurgery of the Second Hospital of Shanxi Medical University between January 2018 and March 2022 were selected,and a total of 39 cases ranged in age from 17 to 66 years(mean 42.3 years),including 12(30.7%)in men and 27(69.3%)in women.All patients in the included studies underwent the author’s physical examination,detailed medical history,and statistics on clinical manifestations such as lumbar pain,buttock pain,abnormal bowel and bowel movements,lower limb pain,sexual dysfunction treatment history,etc.,and preoperative examination and laboratory tests to determine whether the patients had symptomatic-related diseases.Imaging evaluation includes plain radiographs(X-rays),computed tomography(CT)and magnetic resonance imaging(MRI)of the lumbosacral spine,and statistics on the distribution of cyst communication foramen and nerve roots.Laminectomy,decompression,cyst wall incision and drainage,cyst wall resection with capsular neck ligation,or partial cyst wall resection with nerve root sleeve forming pedicle fat and adequate muscle flap tamponade were given to all patients in the included studies.Postoperative statistics on the patient’s symptom relief,the treated patients need 3 months,6 months,12 months of follow-up,and the improvement of the patient’s symptoms during the follow-up period needs to be recorded in detail.Results:After treatment,preoperative symptoms improved significantly in all patients,especially those who complained of low back pain before surgery,while patients who complained of numbness and weakness in the lower extremities,sensory disturbances in the perineal area,or bladder and rectal dysfunction had relatively poor symptom relief.Compared with preoperatively,the digital scale score(NRS)was significantly lower and the IJOA score was significantly higher at the last follow-up;Among them,87.2%(34/39)of patients had complete remission of postoperative symptoms,7.6%(3/39)had partial improvement in symptoms,and 5.1%(2/39)had no change in their condition.Conclusion:For patients with sacral cysts with obvious symptoms,surgical treatment can relieve or prevent further aggravation of symptoms,and can be used as the recommended treatment method,among which for patients with non-radiculotype sacral cysts,sacral laminectomy decompression,cyst resection and cystic neck ligation,pedunculated muscle flap and fat tamponade can be recommended;For patients with radiculosacral cysts,sacral laminectomy decompression,cyst wall incision and drainage,nerve root sleeve molding,pedunculated muscle flap,and fat tamponade may be recommended.