Cerebrospinal fluid leakage (CSFL) is a complication of intravertebral surgery, mostly seen after injury to the dura and arachnoid membranes or incision and suturing during operations such as decompression, adhesion release, intradural and extradural tumor resection, and cyst scraping during exploratory spinal canal surgery. Although the incidence is not high, improper treatment can produce many complications, which can cause ventricular system infection in serious cases and even endanger patients’ lives [1-2]. We retrospectively analyzed the management of 29 patients with complications of CSFL in nearly 1,000 cases of intravertebral surgery performed in our hospital from October 2000 to October 2006, and summarized as follows. Li Bo, Department of Orthopedics, People’s Hospital of Guizhou Province
1 Data and methods
1.1 General data
A total of 967 cases of endospinal surgery were performed from October 2000 to October 2006, of which a total of 29 cases (3%) had CSFL after surgery. There were 18 female cases and 11 male cases, aged 44-82 years old, with an average of 57 years old. CSFL occurred in 14 cases after reoperation for postoperative intradural adhesions, 5 cases after enlargement of the spinal canal for lumbar spinal stenosis, 3 cases after anterior surgery for spinal cervical spondylosis, 2 cases after posterior decompression for cervical OPLL, 3 cases after resection of cervicothoracic intradural tumors, and 2 cases after surgery for sacral cysts. In 28 cases, clear fluid oozed from the drainage tube or the wound from 1 to 3 d after surgery, and the diagnosis was CSFL. In one patient with an intra-sacral canal cyst, a bulge in the lumbosacral region appeared 9 d after surgery, with a fluctuating sensation when touched, and clear fluid was extracted by puncture, and the diagnosis was endocerebrospinal fluid leakage.
1.2 Treatment method
After CSFL was found, all patients were treated conventionally by removing wound drains, suturing to close skin fissures, routine application of antibiotics, hormones, local pressure dressing and compression, and head-high-foot-low position or head-low-foot-high position according to the site of CSFL. 4 of the patients with CSFL above T8, who had poor results with conventional treatment, were treated with continuous drainage of the lumbar subarachnoid space. The specific method of drainage was as follows: the patient was placed in the lateral position, the L3/4 spinous space was taken, and the catheter was placed into the subarachnoid space 5-10 cm through a guide needle punctured between the L3/4 spinous space, and then the guide needle was removed, and when cerebrospinal fluid did flow through the catheter, the sleeve needle was carefully removed and the catheter was left in place. The catheter was connected to a disposable infusion tube and a closed sterile drainage bag. The head of the bed is elevated 10o~30o, and the cerebrospinal fluid drainage starts with no more than 20 drops per minute. The height of the drainage tube is adjusted to control the drainage rate, and 200~400ml of cerebrospinal fluid is collected daily. When headache, nausea or vomiting occurs during drainage, the drainage speed can be adjusted. Simultaneous infusion of fluids, prophylactic use of antibiotics, observation of wound exudation, and attention to water and electrolyte balance.
2 Results
In 23 of the 29 cases, after conventional treatment, the leakage stopped within 1~3 d. The wound healed in 12~14 d. In 4 cases with CSFL above T8, the subarachnoid space of the lumbar spine was continuously drained for 8~12 d. The leakage stopped within 4~6 d and healed after 1 week. In one case of intra-sacral cyst, an internal leakage of cerebrospinal fluid in the lumbosacral region occurred 9 d after surgery, which was not significantly relieved by conventional treatment. 3 months later, the lumbosacral bulge was relatively fixed and limited, without enlargement or reduction, forming a cerebrospinal fluid cyst, and reoperation was recommended. one case of lumbar spinal stenosis was treated with enlargement of the spinal canal after kyphoplasty. The patient was obese, elderly (76 years old), with hypertension, diabetes mellitus, asthma and other medical diseases, and CSFL was treated ineffectively by various methods, resulting in intracranial infection, septic meningitis and death of the spinal canal. 27 of the 29 cases were followed up for 6 to 18 months (mean 12 months) after surgery, and no incisional infection or other complications occurred.
3 Discussion
3.1 Causes of postoperative CSFL after endovascular surgery
The main causes of CSFL leakage after intradural surgery are (1) reoperation due to postoperative adhesions in the spinal canal, the formation of a large amount of scar tissue at the original incision during surgery, the formation of extensive adhesions between the dura and scar tissue, and the easy occurrence of dural and arachnoid tears during the process of adhesion peeling and release; (2) lumbar spinal canal stenosis during spinal canal enlargement, the adhesions between the ligamentum flavum and dura caused by spinal canal stenosis are heavy, and the dura becomes thinner The dura and arachnoid tears may occur due to careless decompression; (3) serious adhesions between the ossified posterior longitudinal ligament and dura, or ossification of the posterior longitudinal ligament with dural ossification, which can easily tear the dura and arachnoid when removing the ossified mass of the posterior longitudinal ligament [3]; (4) subdural tumor or bone cyst after tumor removal or cyst scraping, the dura repair is not tight, and CSFL still occurs within a short period of time; (5) medical origin factors, operator inexperience, careless operation or underestimation of intraoperative difficulties can cause dural and arachnoid injuries; (6) spontaneous CSFL, which may be related to dural dysplasia and degeneration [2, 4]. In our group, 14 cases (nearly 50%) of CSFL occurred after reoperation for postoperative adhesions in the spinal canal, and 10 cases (nearly 30%) of CSFL occurred after surgery for degenerative changes in the spinal canal such as stenosis, hyperplasia, and ossification. Therefore, a full understanding of the condition before surgery and careful intraoperative operation are the keys to reduce and avoid CSFL.
3.2 Prevention and management of CSFL in intraoperative surgery
Preventive measures to avoid CSFL in intraoperative surgery: (1) Adequate knowledge and assessment of the condition should be made before surgery, careful intraoperative operation, and preparation of surgical instruments should be in place; (2) Good lighting, thorough hemostasis, and keeping the operative field clear; (3) Before removing the compressor or scar tissue, the adhesions between the compressor and the dura should be carefully separated, starting from the lighter adhesions and gradually and carefully; (4) When the local dura is found to be (4) when local dural dysplasia or dural defect is found, pay attention to protect the exposed arachnoid membrane to avoid tearing it during suction or separation and causing CSFL; (5) for surgery requiring dural incision, the dura should be carefully sutured after lesion removal, and the suture should be covered with gelatin sponge.
Intraoperative management of CSFL: When dural and arachnoid injuries are found intraoperatively, in principle, they should be repaired immediately to prevent the occurrence of postoperative CSFL. It is quite difficult to repair dural injury or defect at the site of inadequate exposure, especially for small dural defects or irregular tears with sutures, and in this case, gelatin sponge, bioprotein gel or adipose tissue can be filled at the dural breach. If the dural defect is large, it needs to be repaired. Epstein et al [5] reported good results in the repair of dural defects using small titanium clips.
3.3 Management of CSFL after intradural surgery
The general treatment of CSFL after intradural surgery includes bed rest, local compression in prone position, head-high-foot-low or head-low-foot-high position change according to the site of CSFL, wound closure with sutures, application of antibiotics to prevent infection and supportive treatment (e.g. protein and plasma supplementation, prevention or correction of electrolyte disorders). With the above treatments, most of the patients with CSFL can obtain good results. For example, 23 of the 29 patients reported by our group were cured by general treatment. For patients with CSFL in a high location, the treatment of continuous drainage of the subarachnoid space of the lumbar spine can be considered after general treatment is ineffective, and this method has been clinically proven to be a better non-surgical treatment measure [6-7]. The dural fissure is usually healed by 10-14 d of drainage. The exact mechanism is not known, but it may be due to the outflow of cerebrospinal fluid through the catheter rather than through the fissure, which facilitates the healing of the fissure. It is also believed that when the dura is dilated, the dural notch is larger, and after drainage, the cerebrospinal fluid decreases, the pressure drops, and the dural notch narrows, which facilitates the healing of the leak [7]. Four cases in our group were treated with continuous drainage of the subarachnoid space via the lumbar spine for 8-12 d. The leakage stopped within 4-6 d, and the leakage healed after 1 week. During the drainage process, all of them had different degrees of headache, nausea, vomiting and other hypocranial pressure symptoms, which were relieved by symptomatic treatment, and the postoperative follow-up was nearly 1 year with good results. Since more cerebrospinal fluid is lost daily during drainage, attention should be paid to regular biochemical examination and maintenance of water and electrolyte balance.
In conclusion, patients with CSFL should be given great attention. Active prevention, close observation and timely management are crucial. Properly treated, the treatment is effective and the cure rate is very high. Improper management can lead to serious consequences and complications.