MANAGEMENT OF CEREBROSPINAL FLUID LEAKAGE FOLLOWING CERVICAL SPINE SURGERY

Objective To investigate the management and outcome of cerebrospinal fluid leakage(CSFL)after cervical surgery.Methods Medical records of 642 patients who underwent cervical surgery between December 1999 and December 2005 at our hospital were retrospectively reviewed.Five patients complicated by CSFL after surgery were enrolled,of which 4 cases were complicated after ossified posterior longitudinal ligament or posterior vertebral osteophyte resection directly injuring the dura,and 1 case after posterior cervical double-door laminoplasty without observed dural injury during surgery.Of the 5 CSFL cases,4 cases occurred at 1-3 days after operation and 1 case at 9 days after operation.All 5 postoperative CSFL cases were treated through wound drainage removal,wound sutures,prophylactic antibiotics,and continuous subarachnoid drainage in the elevated head position.Results All 5 CSFL cases experienced leakage cessation within 1-3 days and wound healing within 4-8 days,and subarachnoid drainage lasted 11-16 days with an average volume of 320 mL(range,150-410 mL).Four cases experienced headache,nausea and vomiting,1 case suffered from somnolence and hyponatremia,and symptoms subsided after symptomatic treatment and intravenous fluid administration.All patients were followed up for an average of 32 months(range,22-50 months).No occurrence of cerebrospinal fluid cyst or wound infection was observed.CSFL produced no significant negative effects upon neuromuscular function recovery.Conclusion Continuous subarachnoid cavity drainage in combination with elevated head position is a simple and safe non-surgical method in treatment of CSFL following cervical surgery.

Individualized Sellar Floor Reconstruction Method and Nursing Strategy for the Intraoperative Cerebrospinal Fluid Leakage Caused by Neuroendoscopic Transsphenoidal Pituitary Adenoma Resection

Objective: To explore the clinical effect of and the method and nursing strategy for sellar reconstruction for intraoperative cerebrospinal fluid (CSF) leakage in pituitary adenoma resection under neuroendoscopy. Methods: The data from 20 cases of intraoperative CSF leak caused by transsphenoidal pituitary adenoma resection were retrospectively analyzed. Six patients were treated with mucosal flap and artificial dural reconstruction of sellar (simple sellar floor reconstruction). In 45 patients, autologous fat, fascia lata, and artificial dura were used to repair and reconstruct the sellar floor (multilayer sellar floor reconstruction). After the operation, all patients underwent follow-up for 6 - 24 months. Results: Fifty patients were followed up without CSF leakage. One patient was cured after leakage of CSF through the lumbar cistern 1 month after discharge. Conclusion: For patients with CSF leakage during neuroendoscopic transsphenoidal pituitary adenoma resection, individualized sellar floor reconstruction should be adopted according to the degree of CSF leakage and the size of the sellar floor defect. Strict nursing measures can effectively prevent CSF leakage and reduce postoperative complications.

Cerebrospinal Fluid Leakage after Thoracic Decompression

Objective： The objective of this study is regular and special features. to review cerebrospinal fluid leakage （CSFL） after thoracic decompression and describe its Data Sources： Literature cited in this review was retrieved from PubMed and Medline and was primarily published during the last 10 years. ＂Cerebrospinal fluid＂, ＂leakage＂, ＂dural tears＂, and ＂thoracic decompression＂ were the indexed terms. Relevant citations in the retrieved articles were also screened to include more data. Study Selection： All retrieved literature was scrutinized, and tbur categories were recorded： incidence and risk factors, complications, treatment modalities, and prognosis. Results： CSFL is much more frequent after thoracic decompression than after cervical and lumbar spinal surgeries. Its occurrence is related to many clinical factors, especially the presence of ossified ligaments and the adhesion of the dural sac. While its impact on the late neurological recovery is currently controversial, CSFL increases the risk of other perioperative complications, such as low intracranial pressure symptoms, infection, and vascular events. The combined use of primary repairs during the operation and conservative treatment postoperatively is generally effective for most CSFL cases, whereas lumbar drains and reoperations should be implemented as rescue options for refractory cases only. Conclusions： CSFL after thoracic decompression has not been specifically investigated, so the present study provides a systematic and comprehensive review of the issue. CSFL is a multi-factor-related complication, and pathological fators play a decisive role. The importance of CSFL is in its impact on the increased risk of other complications during the postoperative period. Methods to prevent these complications are in need. In addition, though the required treatment resources are not special for CSFL after thoracic decompression, most CSFL cases are conservatively curable, and surgeons should be aware of it.

Subdural fluid collection rather than meningitis contributes to hydrocephalus after cervical laminoplasty:A case report

BACKGROUND Hydrocephalus following dural tear after spinal surgery is rare.Although a few cases of obstructive hydrocephalus caused by subdural fluid collection and communicating hydrocephalus associated with meningitis have been reported,the mechanism remains uncertain.Herein we describe a patient complicated with hydrocephalus after cervical laminoplasty in whom subdural fluid collection in the cervical spine and posterior cranial fossa rather than chronic meningitis was the main mechanism.CASE SUMMARY A 45-year-old man underwent cervical laminoplasty for cervical spondylotic myelopathy at a local hospital.Ten days postoperatively,a high fever occurred and magnetic resonance imaging(MRI)showed cerebrospinal fluid(CSF)leakage.Pseudomeningocele liquid test showed high levels of protein and white blood cell(WBC)count with negative bacterial culture.The patient was treated with shortterm intravenous antibiotic and discharged with normal body temperature.The patient was uneventful during the first 8 mo follow-up although repeated MRI showed persistent pseudomeningocele.At the 9th mo postoperatively,the patient gradually presented with dizziness and headache accompanied by recurrent weakness of his left arm.Imaging examinations demonstrated hydrocephalus and a cystic lesion around the cervical spinal cord.CSF test from lumbar puncture indicated chronic meningitis.MRI on 1 d after pseudomeningocele drainage showed a significant decrease in the cystic volume,suggesting that the cystic lesion would be subdural fluid collection rather than adhesive arachnoiditis.After dural defect repair,the patient’s symptoms completely resolved and hydrocephalus gradually disappeared.CSF analysis at the 21-mo follow-up revealed significantly decreased protein level and WBC count.CONCLUSION Subdural fluid collection rather than meningitis contributes to the hydrocephalus formation after cervical laminoplasty.

Late presentation of dural tears:Two case reports and review of literature

BACKGROUND The late presentation of dural tears(LPDT)has a low incidence rate and hidden symptoms and is easily ignored in clinical practice.If the disease is not treated in time,a series of complications may occur,including low intracranial pressure headache,infection,pseudodural cyst formation,and sinus formation.Here,we describe two cases of LPDT.CASE SUMMARY Two patients had sudden fever 1 wk after lumbar surgery.Physical examination showed obvious tenderness in the operation area.The patients were confirmed as having LPDT by lumbar magnetic resonance imaging and surgical exploration.One case was caused by continuous negative pressure suction and malnutrition,and the other was caused by decreased dural ductility and low postoperative nutritional status.The first symptom of both patients was fever,with occasional headache.Both patients underwent secondary surgery to treat the LPDT.Dural defects were observed and dural sealants were used to seal the dural defects,then drainage tubes were retained for drainage.After the operation,the patients were treated with antibiotics and the patients’surgical incisions healed well,without fever or incision tenderness.Both recovered and were discharged 1 wk after the operation.CONCLUSION LPDT is a rare complication of spinal surgery or neurosurgery that has hidden symptoms and can easily be overlooked.Since it may cause a series of complic-ations,LPDT needs to be actively addressed in clinical practice.

RECONSTRUCTION OF THE SELLAR FLOOR FOLLOWING TRANSSPHENOIDAL SURGERY USING GELATIN FOAM AND FIBRIN GLUE

Objective To introduce a new principle of sellar reconstruction and to evaluate the effectiveness of absorbable gelatin foam and fibrin glue for sellar reconstruction. Methods A total of 176 consecutive patients who underwent surgery for pituitary adenomas, cysts, chordomas, or subdiaphragmatic craniopharyngiomas in the sella turcica between January 2001 and April 2003 at Peking Union Medical College Hospital were enrolled. Different techniques of sellar closure and indications for each specific condition were retrospectively reviewed. Results Seventy-seven (43.7%) patients developed a visible cerebrospinal fluid (CSF) leakage during surgery. Intra- operative CSF leakage were repaired simply with gelatin foam and fibrin glue in 62 (35.2%) patients, and with autologous fat graft and sellar floor reconstruction in 15 (8.5%) patients. Postoperative CSF rhinorrhea occurred only in 1 case. There were no visual deterioration, allergic rhinitis, meningitis, pneumocranium, granulomas, or other complications asso- ciated with the reconstruction procedure. Conclusion The procedure of using gelatin foam and fibrin glue and principle of cranial base reconstruction is safe and effective in preventing postoperative complications following transsphenoidal surgery.

Successful management of depression skull fracture in a boy with dog bite injury:A case report

Rationale:There are many cases of daily reported dog bite injuries around the world.However,craniofacial fractures owing to dog bites are quite rare.They are frequently seen in the pediatric age group.Here,we report the successful management of a pediatric patient with depression skull fracture due to a dog bite injury.Patient’s concerns:A 3-year-old boy was admitted to the emergency department with a complicated skull fracture due to a dog bite injury.In physical examination,the patient was neurologically intact.He had hemorrhagic scalp wounds.Cerebrospinal fluid was leaking on the right temporal and frontal sides.Diagnosis:Cranial computed tomography revealed pneumocephalus,brain edema,and compound fracture associated with right frontal concussion.Intervention:After decompressive craniectomy,duraplasty was performed by placing a galea graft.Depressed fractures were removed and subdural bleeding control was provided.Outcomes:Perioperative and postoperative periods were uneventful.Lessons:Emergency medicine physicians should control possible underlying fracture lines in pediatric head trauma caused by dog bites.

Safety and biodegradability of a synthetic dural sealant patch(Liqoseal)in a porcine cranial model

Background:Liqoseal consists of a watertight layer of poly(ester)ether urethane and an adhesive layer containing polyethylene glycol-N-hydroxysuccinimide(PEG-NHS).It is designed to prevent cerebrospinal fluid(CSF)leakage after intradural surgery.This study assessed the safety and biodegradability of Liqoseal in a porcine craniotomy model.Methods:In 32 pigs a craniotomy plus durotomy was performed.In 15 pigs Liqoseal was implanted,in 11 control pigs no sealant was implanted and in 6 control pigs a control dural sealant(Duraseal or Tachosil)was implanted.The safety of Liqoseal was evaluated by clinical,MRI and histological assessment.The degradation of Liqoseal was histologically estimated.Results:Liqoseal,2 mm thick before application,did not swell and significantly was at maximum mean thickness of 2.14(±0.37)mm at one month.The foreign body reaction induced by Liqoseal,Duraseal and Tachosil were comparable.Liqoseal showed no adherence to the arachnoid layer and was completely resorbed between 6 and 12 months postoperatively.In one animal with Liqoseal,an epidural fluid collection containing CSF could not be excluded.Conclusion:Liqoseal seems to be safe for intracranial use and is biodegradable.The safety and performance in humans needs to be further assessed in clinical trials.

Experimental Investigation of the Sealing Performance of Honeycomb Seals

The test results of sealing performance and a comparison between three types of honeycomb seals and a type of labyrinth seal are presented, which have different seal clearances and work under various rotor speeds. It has been found that the honeycomb seal leakage during a rotor speed of 6000 r/min decreases by about 4.8 percent as compared with that during a rotor speed of 0 r/min. At a radial clearance of 0.12 mm the honeycomb seal with a cell size of 1.6 mm enjoys the best sealing performance. The leakage flow of the labyrinth seal with a radial clearance of 0.06 mm is smaller than that of the honeycomb seals.

Large scale gas leakage monitoring with tunable diode laser absorption spectroscopy

Tunable diode laser absorption spectroscopy （TDLAS） has been widely employed in atmospheric trace gases detecting and industrial control due to its high sensitivity, selectivity, and rapidity of response. An open path TDLAS system is developed for monitoring large scale methane leakage around the oil refinery. The tunable distributed feedback （DFB） diode laser emits at 1.65 pro. In order to enhance the sensitivity, a system combining long open path and second harmonic detection technique is developed. The test results show that the time resolution is less than 0.1 second and the detection limit is lower than 3.6 ppmv. This system is adapted for monitoring a large scale methane concentration changing trend instead of measuring its absolute concentration.

UNCONFINED SEEPAGE ANALYSIS OF DISCONTINUOUS ROCK SLOPE

Unconfined seepage field of arch dam abutment slope was studied. This paper is composed of two parts. The first part concerns with the numerical methods used in the analysis, which includes the identification of rock blocky system and the algorithm of the unconfined seepage flow in the discontinuity network with the consideration of the grouting curtain and drainage curtain. In the second part a complicated arch dam abutment slope was studied, for which the seepage flow field characteristics was analyzed and the seepage control system was evaluated.

ADAPTIVE FEM ANALYSIS FOR TWO-DIMENSIONAL UNCONFINED SEEPAGE PROBLEMS

A methodology for the adaptive FEM analysis of two-dimensional seepage problems with free surface has been proposed. The methodology is based on three main aspects: (1) the advancing-front quadrilateral mesh generation technique, (2) the FEM analysis of the seepage problems with free surface, (3) a posteriori error estimator and refined mesh size estimator. An example of embankment dam with toe drain was studied.

MODEL EXPERIMENT RESEARCH ON CROSS FRACTURE FLOW

Research of local head loss of cross fracture flow was studied by model experiments. A theoretical model of local head loss of cross fracture flow was founded by the use of the momentum law of water flow. Through the correlation analysis between experimental results and theoretical results, the correction coefficient of the theoretical model is definite. The proposed calculation formula of local head loss of cross fracture flow can be used to analyze the problem of network fracture seepage.

NONSTRUCTED GRID MESH FINITE VOLUME METHOD AND APPLICATION

The finite volume method (FVM) has been used and applied. Gauss theorem was used to transfer volume integration to area integration and the relation formula of nodes around each element was found based on the constancy of flux into and out of element. This method with free cubic element was applied in 3-D seepage and tidal flow problems. It can be found that the seepage flux with FVM method is more accurate than FEM method. The FVM has the advantages of good stability, convenience of solving, easy programming, less computing time and storage.