Risk factors for unintended durotomy during spine surgery: a multivariate analysis

BACKGROUND CONTEXT

Incidental durotomy during spine surgery is a common occurrence, with a reported incidence ranging from 3% to 16%. Risk factors identified by prior studies include age, type of procedure, revision surgery, ossification of the posterior longitudinal ligament, gender, osteoporosis, and arthritis. However, these studies are largely univariate analyses using retrospectively recorded data.

PURPOSE

To identify and quantify statistically significant risk factors for inadvertent durotomy during spine surgery.

STUDY DESIGN

Multivariate analysis of prospectively collected registry data. The University of Washington Spine End Results Registry 2003 and 2004 is a compilation of prospectively collected detailed data on 1,745 patients who underwent spine surgery during 2003 to 2004.

PATIENT SAMPLE

One thousand seven hundred forty-five patients underwent spine surgery from 2003 to 2004 at our two institutions.

OUTCOME MEASURES

Cardiac, pulmonary, gastrointestinal, neurologic, renal, and urologic complications defined a priori data collection.

METHODS

Using these data, univariate and multivariate statistical analyses were performed to identify and quantify risk factors for incidental durotomy during spine surgery. Relative risk (RR) values with valid confidence intervals and p values were determined using these data.

RESULTS

Our multivariate analysis demonstrated that age, lumbar surgery, revision surgery, and elevated surgical invasiveness are significant risk factors for unintended durotomy. Of these, revision surgery was the strongest risk factor for dural tear (RR, 2.21). Diabetes was a significant risk factor in the univariate analysis but not in the multivariate analysis.

CONCLUSIONS

Revision surgery, age, lumbar surgery, degenerative disease, and elevated surgical invasiveness are significant risk factors for unintended durotomy during spine surgery. These data can be useful to surgeons and patients when considering surgical treatment.

Pain, postdural puncture headache, nausea, and pruritus after cesarean delivery: a survey of prophylaxis and treatment

BACKGROUND

The need for a cesarean delivery may interfere negatively with the overall experience of childbirth. Several factors related to anesthesiological management such as postoperative pain and discomfort, nausea and pruritus, and postdural puncture headache (PDPH), may lead to dissatisfaction and have a negative impact on early mobilization and a new mother's ability to care for her newborn baby. Optimal prophylaxis and treatment decrease these complications, increase satisfaction, and prevent chronic pain. This survey determined how prophylaxis and treatment of pain, PDPH, nausea, and pruritus after cesarean section (CS) is managed.

METHODS

A questionnaire was sent to 709 departments of anesthesiology serving an obstetric unit in Germany. The questionnaire asked about different aspects of pain management, the management of accidental dural puncture (ADP), and treatment of PDPH. Further we asked about therapy and prophylaxis of nausea and pruritus in the peripartal setting.

RESULTS

In all, 360 questionnaires (50.8%) were returned; 346 were complete and analyzed (accounting for 330000 births per year). Paracetamol (77.5%) and piritramide (85.6%) are the most common analgesics used. If epidural catheters were used for anesthesia for CS, 47.7% were used for postoperative pain therapy. However, 92.7% of the departments removed catheters in less than 24 hours after delivery. In case of an ADP most departments (69.9%) repeated puncture, 2.6% placed catheters intrathecally. Median blood volume for an epidural blood patch was 10ml.

CONCLUSION

Apart from conservative treatment of PDPH, prophylaxis and treatment of pain after cesarean delivery, PDPH, nausea, and pruritus varied widely, indicating the need for the qualitative evaluation of overall management.

[Postraumatic epidural arachnoid spinal cyst: case report]

INTRODUCTION

Extradural arachnoid spinal cysts are unfrequent lesions that are associated with spinal trauma, surgery and less frequently with congenital anomalies. The clinical manifestations are similar to those seen with other compressive spinal cord lesions. Magnetic resonance techniques allow to diagnose correctly this pathology and to define its thopographic situation. The pathologic history of the patient is essencial to establish the ethiology. Surgery is the elective treatment in most cases.

CLINICAL CASE

The patient is a 35 years old man who has a medical history of penetrating spinal trauma two years ago. In that instance he suffered an unilateral spinal cord section at D2-D3 level with the corresponding Brown Sequard syndrome. A small wound was detected at the skin dorsal level and it was closed without difficulties. At the beginning, he improved his motor right leg function with rehabilitation and vitamins. After two years of good recovery he came to our hospital suffering a neurological deterioration of six months of evolution. The physical examination revealed an spastic paraparesis. Magnetic resonance was performed demonstrating a cystic extradural collection compressing the spinal cord at D3-D4 level. Surgical decompressive treatment allowed to excise the cyst and it was possible to define a dural tear that was closed successfully. The outcome was good with restoration of the initial motor function that he had after the spinal trauma.

CONCLUSIONS

Surgical management of postraumatic epidural arachnoid spinal cyst allows to detect the meningeal tear and to close it, which is highly effective on these kinds of lesions.

Management of accidental dural puncture and post-dural puncture headache after labour: a Nordic survey

BACKGROUND

a major risk with epidural analgesia is accidental dural puncture (ADP), which may result in post-dural puncture headache (PDPH). This survey was conducted to explore the incidence of ADP, the policy for management of PDPH and the educational practices in epidural analgesia during labour in the Nordic countries.

METHODS

a postal questionnaire was sent to the anaesthesiologist responsible for Obstetric anaesthesia service in all maternity units (n=153) with questions relating to the year 2008.

RESULTS

the overall response rate was 93%. About 32% (22-47%) of parturients received epidural analgesia for labour. There were databases for registering obstetric epidural complications in 13% of Danish, 24% of Norwegian and Swedish, 43% of Finnish and 100% of hospitals in Iceland. The estimated incidence of ADP was 1% (n approximately 900). Epidural blood patch (EBP) was performed in 86% (n≈780) of the parturients. The most common time interval from diagnosis to performing EBP was 24-48 h. The success rate for EBP was >75% in 67% (62-79%) of hospitals. The use of diagnostic CT/MRI before the first or the second EBP was exceptional. No major complication was reported. Teaching of epidurals was commonest (86%) in the non-obstetric population and 53% hospitals desired a formal training programme in obstetric analgesia.

CONCLUSION

we found the incidence of ADP to be approximately 1%. EBP was the commonest method used for its management, and the success rate was high in most hospitals. Formal training in epidural analgesia was absent in most countries and trainees first performed it in the non-obstetric population.

Dural tear post mastoidectomy repaired with Dura Gen

Dural exposure may occur during the course of thinning the tegmen tympani and tegmen mastoideum in mastoid procedure. If large area of dura is exposed or lacerated, cerebrospinal fluid and brain herniation may enter the mastoid cavity. We report a case of a patient with injured dura mater and tegmen mastoideum during mastoidectomy for chronic suppurative otitis media with cholesteatoma managed by using DuraGen. The dura mater and tegmen defect healed totally showing the success of the procedure. A collagen matrix like DuraGen is an option for repairing dural tear in mastoid region.

Paresis of cranial nerve VI (N. abducens) after thoracic dural perforation

Epidural anesthesia is associated with the risk of unintended dural perforation and concomitant leakage of cerebrospinal fluid (CSF) from the subarachnoidal space. This may remain asymptomatic or trigger post-dural puncture headache (PDPH). Cerebral nerve lesions after attempted epidural anesthesia are very rare. Here we report a case of unilateral paresis of the cranial nerve VI (N. abducens) after attempted thoracic epidural anesthesia. Herein, diagnosis of N. abducens paresis was probably delayed because the optical symptoms, such as blurred and double vision, were attributed to optical hallucinations caused by a concomitant (S)-ketamine infusion. In all patients with optical symptoms such as blurred or double vision a paresis of the abducens nerve should be considered.

[Iatrogenic dural lesions in lumbar neural decompressive surgery]

INTRODUCTION

Iatrogenic dural tear with cerebrospinal fluid leakage is a known complication of lumbar surgery of the columna. In the literature, the incidence is 3-16%.

MATERIAL AND METHODS

The study was a retrospective, consecutive review of electronic patient records after spinal surgery at the Private Hospital Hamlet. The study covers cases from the 10-month period from September 1, 2007 to June 30, 2008. Data was collected after this period and consists of surgeon-documented dural tears. At the time of surgery, the surgeon was unaware that there would be a subsequent registration. A total of 634 patients had lumbar neural decompressive surgery - 479 patients were treated for spinal stenosis and 155 for prolapsed disc.

RESULTS

The incidence of dural tear was 3.9% (25 dural tears in 634 operations). The risk of a dural tear after secondary surgery was 7.9% versus 3.3% for primary (p = 0.02) and the mean age was 65.9 years for patients with dural tear compared with 58.1 years for patients without (p = 0.00). The difference in the mean duration of surgery was significant being 72 minutes in the group suffering a dural tear compared with 56 minutes (p = 0.03) among the remaining patients, and in the former group length of stay was increased by 1.1 day (p = 0.00).

CONCLUSION

The incidence of iatrogenic dural tear was 3.9%. The incidence of dural tear was doubled in secondary surgery. The duration of surgery increased by 16 minutes and the patients with dural tear were also hospitalized one day longer.

[Monitoring skill acquisition in obstetric epidural puncture at a university hospital using the cumulative sum method]

BACKGROUND AND OBJECTIVE

Skill acquisition in anesthesiology is subject to a great deal of interindividual variability. Our aim was to develop and test an individualized tool for monitoring acquisition of technical skills based on the cumulative sum (CUSUM) approach. This system objectively assesses whether an individual has acquired a minimum skill level and identifies the moment when the skill has been learned.

MATERIAL AND METHODS

Nine third-year residents in anesthesiology and postoperative recovery care participated. The residents anonymously recorded their first 100 obstetric epidural analgesia procedures in a database. The data were then analyzed with the CUSUM method. We considered acceptable skill acquisition to be reflected by a first-attempt success rate of 80% and a rate of success with help of 20%.

RESULTS

A total of 765 epidural blocks were analyzed, giving a mean (SD) of 84.7 (2.8) procedures per resident (range, 47-100 procedures per resident). Seven residents became competent with the skill after 23 procedures and 2 residents were not successful in learning the skill. At the end of the study, 3 residents had required help with more than 20% of the procedures. Data collection from the trainees seemed to vary, leading to possible under- or overestimation of failures and/or need for help. Accidental dural puncture occurred 6 times (0.78%) and blood vessel puncture 40 times (5.2%).

CONCLUSIONS

Although some third-year residents reach the targeted rate of success quickly, we believe that close supervision is useful to control progress along the learning curve for individuals who need more help.

An unusual presentation of head injury: teeth in brain

Penetrating injuries other than gunshot wounds or low-velocity wounds to the head are extremely rare. We report the case of a 19 year old male who sustained a penetrating craniocerebral trauma following a road traffic accident. Noncontrast CT scan revealed three foreign bodies embedded in left frontal lobe, which on surgery turned out to be human teeth. Mechanism of injury seems to share characteristics of low velocity projectiles. The survey of management pattern of these injuries showed a general agreement about CT scan, antibiotics and anticonvulsants. The prompt management resulted in an excellent outcome. We discuss the management of this unusual case reviewing the current literature on craniocerebral injuries caused by similar objects.

Dural lesions in lumbar disc herniation surgery: incidence, risk factors, and outcome

In lumbar disc herniation surgery, dural lesions seem to be the most common complication today. Studies on incidence of and outcome after a dural lesion are mainly based on retrospective studies. In a prospective study within the framework of the Swedish Spine Register, 4,173 patients operated on for lumbar disc herniation were evaluated using pre- and 1-year postoperative protocols and complication registration. Mean patient age was 41 (18-81) years and 53% of the patients were male. 93% of the operations were performed on the two lowermost lumbar levels. The incidence of dural lesions in the material was 2.7%. In patients with previous disc surgery, the incidence was doubled, 5%, a significant increase (P = 0.02). Patients with dural lesions preoperatively had more back pain and inferior scores in general health and role emotional domains of the SF-36. These factors, however, were because they had been operated on previously, not related to the dural lesion as such. The relative improvement after surgery was similar whether a dural lesion had occurred or not. It is concluded that a dural lesion is a technical complication which must be solved at the time of surgery but which does not bear any negative implications on the long-term outcome for the patient.

Dural suturing for repair of cerebrospinal fluid leak in transnasal transsphenoidal surgery

OBJECTIVE

Repair of a cerebrospinal fluid (CSF) leak after transsphenoidal surgery (TSS) is usually accomplished using various graft materials. These methods are effective in most, but not all, cases.

METHODS

Since 2006, we have been directly suturing the sellar floor dura in patients with an intraoperative CSF leak. Fat and/or fascial grafts were utilized only when a major CSF leak developed. The incidence of postoperative CSF rhinorrhea was compared before and after the suture.

RESULTS

Postoperative CSF rhinorrhea developed in 3.7% (7 out of 188) of cases before 2005, but never since the dural suture was introduced (0 out of 136, 0%; P = 0.0229). Although watertight closure was not achieved in some cases, narrowing the dural defect and supporting the intrasellar graft was attained in every case. Surgical time was approximately 30 min longer in patients who underwent dural suture (148 +/- 42 min) than those who did not (119 +/- 37 min; P = 0.0001).

CONCLUSION

Direct suturing of the sellar dura is a simple, safe, and reliable surgical technique for repairing CSF leaks after TSS. Using this procedure, more than 70% of patients with an intraoperative CSF leak can avoid autologous tissue grafts.

[Quantitative test to distinguish spinal fluid from saline solution in combined spinal-epidural anesthesia]

OBJECTIVES

To validate the use of a digital blood glucose meter for detecting the presence of spinal fluid during combined spinal-epidural anesthesia in terms of specificity, positive and negative predictive values, and likelihood ratios.

PATIENTS AND METHODS

Validation was studied in 30 patients scheduled for surgery under combined spinal-epidural anesthesia. A positive finding, defined as detection of spinal fluid return or aspiration by the epidural or spinal needle, was compared with results of standard reference tests (the pattern of sensory or motor block after administration of the local anesthetic). After locating the epidural space with saline solution, the test was performed and 3 mL of local anesthetic was administered. If no sensory or motor blockade was evident, the test was considered a true negative. Spinal puncture was then performed, the test was repeated, and 2 to 3 mL of local anesthetic was injected. The test was considered a true positive if sensory or motor blockade was evident. These findings entered into the validation analyses.

RESULTS

Sensitivity was 100%, specificity 94%, positive predictive value 93%, negative predictive value 100%, the positive likelihood ratio 15.5, and negative likelihood 0.

CONCLUSION

Blood glucose meter readings provide a valid quantitative measure for distinguishing spinal fluid from saline solution during combined spinal-epidural anesthesia. The method, which uses a readily available device, is easy to use to rule out the presence of spinal fluid.

[Headache following laparotomy; chronic subdural haematoma following epidural anaesthesia]

A 63-year-old man underwent an exploratory laparotomy because of rectal carcinoma. The operation was performed under general anaesthesia in combination with epidural anaesthesia. Since the operation the patient complained of a headache. Eight weeks after the operation he was hospitalized because of worsening of the headache and also drowsiness. A physical examination showed a slight tendency to incline to the left. A CT scan showed a subdural haematoma, which was relieved with surgery. We suspected that accidental puncture of the dura caused the haematoma. The incidence, causes, symptoms, diagnosis and treatment of this rare complication are discussed.

[Massive pneumocephalus and cerebrospinal fluid fistula after thoracotomy]

We report the case of a 70-year-old man (ASA physical status 2) who developed massive pneumocephalus caused by a fistula between the subarachnoid and pleural spaces following a left pneumonectomy. After an uneventful immediate postoperative period, the patient was readmitted to the recovery care unit with dyspnea, intense headache, confusion, and diminished level of consciousness. Computed tomography confirmed a cerebrospinal fluid fistula secondary to the opening of the intradural space during tumor resection. Treatment was conservative, consisting of rest in a slightly Trendelenburg position, antibiotic prophylaxis to prevent meningitis, and a water seal on the thoracic drainage tube.

Use of self-closing U-clips for dural repair in mini-invasive surgery for herniated disc

OBJECT

The feasibility of a new technique of dural repair (self-closing U-clips) in mini-invasive surgery for herniated disk is demonstrated in this case report.

MATERIALS AND METHODS

A 44-year-old male patient underwent lumbar microdiscectomy at out Institute, with subsequent dural leak as surgical complication; the dural leak re-appeared even after a second intervention in which we used muscle and dural graft and fibrin glue to repair the leak. We then decided to employ self-closing nitinol- U-clip to achieve primary dural closure.

RESULTS

After the intervention the patient no more presented signs or symptoms due to the unintended durotomy, and the postoperative course was uneventful.

CONCLUSION

Self-closing nitinol U-clips (Medtronic, Inc., Minneapolis) can be used for closing a dural tear through a mini-invasive approach that could make a conventional microsuturing technique very difficult.