Prone versus knee-chest position for microdiscectomy: a prospective randomized study of intra-abdominal pressure and intraoperative bleeding

Navigating Anesthetic Challenges in Multiple Spinal Hydatid Cysts

Spinal hydatid disease is a rare form of hydatid disease caused by the larval stage of Echinococcus granulosus. It refers to a range of conditions that affect the spinal cord, the spine, or both. The prevalence of spinal hydatid disease is highest in the thoracic spine; however, it can also occur in other regions of the spine. In this case report, we present an unusual occurrence of numerous hydatid cysts in a 42-year-old male living in a remote region. The patient has been experiencing a progressive loss of power in his lower limbs, urine incontinence, and back pain for the past four months. The patient was found to have many distinct cystic lesions with spinal cord compression syndrome. Spinal hydatidosis is an uncommon illness that causes significant suffering and has a bleak outlook. When evaluating a patient with spinal compression syndrome, it is important to evaluate this as one of the potential causes.

Paediatric Spinal Deformity Surgery: Complications and Their Management

Surgical correction of paediatric spinal deformity is associated with risks, adverse events, and complications that must be preoperatively discussed with patients and their families to inform treatment decisions, expectations, and long-term outcomes. The incidence of complications varies in relation to the underlying aetiology of spinal deformity and surgical procedure. Intraoperative complications include bleeding, neurological injury, and those related to positioning. Postoperative complications include persistent pain, surgical site infection, venous thromboembolism, pulmonary complications, superior mesenteric artery syndrome, and also pseudarthrosis and implant failure, proximal junctional kyphosis, crankshaft phenomenon, and adding-on deformity, which may necessitate revision surgery. Interventions included in enhanced recovery after surgery protocols may reduce the incidence of complications. Complications must be diagnosed, investigated and managed expeditiously to prevent further deterioration and to ensure optimal outcomes. This review summarises the complications associated with paediatric spinal deformity surgery and their management.

Surgical management of lumbar spinal stenosis in patients over 80: is there an increased risk?

Management of lumbar spinal stenosis (LSS) represents the first cause of spinal surgery for the elderly and will increase with the aging population. Although the surgery improves quality of life, the procedure involves anaesthetic and operative risks. The aim of this study was to assess whether the postoperative complication rate was higher for elderly patients and to find confounding factors. We conducted a retrospective study including all LSS surgeries between 2012 and 2020 at the University Hospital of Caen. We compared two populations opposing patients aged over 80 with others. The primary endpoint was the occurrence of a severe complication (SC). Minor complications were the secondary endpoint. Comorbidities, history of lumbar spine surgery and surgical characteristics were recorded. Nine hundred ninety-six patients undergoing surgery for degenerative LSS were identified. Patients over 80 were significantly affected by additional comorbidities: hypertension, heart diseases, higher age-adjusted comorbidity Charlson score, ASA score and use of anticoagulants. Knee-chest position was preferred for younger patients. Older patients underwent a more extensive decompression and had more incidental durotomies. Of the patients, 5.2% presented SC. Age over 80 did not appear to be a significant risk factor for SC, but minor complications increased. Multivariate analysis showed that heart diseases, history of laminectomy, AA-CCI and accidental durotomies were independent risk factors for SC. Surgical management for lumbar spinal stenosis is not associated to a higher rate of severe complications for patients over 80 years of age. However, preoperative risk factors should be investigated to warn the elderly patients that the complication risk is increased although an optimal preparation is the way to avoid them.

A practical guide to patient position and complication management in neurosurgery: a systematic qualitative review

PURPOSE

Adequate patient positioning is of paramount importance in neurosurgery. Complications related to the position are common and make up for more than 16% of the claims towards anaesthesiologists and neurosurgeons. This paper aims to provide the anaesthesiologist with a practical guide to avoid common pitfalls related to the patient positioning process.

METHOD

We performed a systematic review of the medical literature for the identification, screening, and inclusion of articles. The bibliographic search was conducted on June 1st, 2021 by two of the authors. In this review, we included articles indexed by MEDLINE, Cochrane Library, or Google Scholar.

RESULTS

We retrieved a total of 5706 unique papers from our initial search. However, after the initial screening, 5363 papers were removed is not related to our research leaving a total of 343 papers. We examined the full text of all the 343 articles including 68 of them in the final qualitative analysis.

DISCUSSION

In this review we examine the most common neurosurgical positions: supine, sitting, lateral, park-bench, prone, jack-knife, and knee-chest. For each of them, the proper positioning and related complications are described. Particular attention is given to the prevention and management of these complications, providing a practical guide for clinicians.

A Comparative Evaluation of the Effect of Prone Positioning Methods on Blood Loss and Intra-Abdominal Pressure in Obese Patients Undergoing Spinal Surgery

Background Improper prone positioning of obese patients for spine surgery can increase the intra-abdominal pressure (IAP), resulting in increased bleeding from epidural venous plexus. The choice of prone positioning frame can be an important determinant of the IAP.

Materials and Methods This prospective, randomized study was performed on obese patients (body mass index ≥ 30) scheduled for lumbar laminectomy. After administration of general anesthesia, patients were positioned prone either on Wilson’s frame (group W), or on horizontal bolsters (group H). IAP was recorded at three intervals: (1) in supine position, (2) 10 minutes after prone positioning, and (3) in prone position at the end of surgery. Intraoperative blood loss was measured quantitatively and assessed subjectively by the surgeon.

Results A total of 60 patients were enrolled with 30 patients in each group. IAP in supine position was similar in both groups. However, IAP 10 minutes after prone positioning was significantly higher at 11.44 ± 1.61 mm Hg in group W as compared to 9.56 ± 1.92 mm Hg in group H (p = 0.001). Similarly, IAP of 12.24 ± 1.45 mm Hg in group W, measured on completion of surgery was significantly higher than 9.96 ± 2.35 mm Hg in group H (p = 0.001). Mean total blood loss of 440.40 ± 176.98 mL in group W was significantly higher than 317.20 ± 91.04 mL in group H (p = 0.003).

Conclusion Obese patients positioned prone on Wilson’s frame had significantly higher IAP and blood loss compared to patients positioned on horizontal bolsters.

Positioning issues of spinal surgery during pregnancy

BACKGROUND

Albeit rarely, different spinal pathologies may require surgical treatment during pregnancy. The management of such cases poses a series of challenges, starting with adequate body positioning.

OBJECTIVE

To illustrate limits and indications of the different surgical positioning strategies for pregnant women undergoing spine surgery.

METHODS

We performed a systematic review of literature about the described surgical positioning strategies used for spinal surgery during pregnancy, discussing advantages, indications, and limits. We also describe of a novel three-quarters prone positioning for dorsal pathology.

RESULTS

The surgical strategy may vary according to several factors, such as the location and the nature of the underlying pathology, the stage of the pregnancy, and the clinical condition of mother and fetus. During the second trimester, the habitus begins to raise issues about both the abdominal and the aortocaval compressions. The third trimester implies neonatal and ethical challenges: both fetal monitoring and the possibility of urgently proceeding to delivery should be guaranteed. The prone position is feasible during the second trimester provided an adequate frame is supplied. The lateral or three-quarters prone positioning may offer the safest option in the last stages of pregnancy, whereas both supine and sitting positionings are anecdotal.

CONCLUSIONS

Gestational age, surgical comfort and maternofetal safety should be balanced by a multidisciplinary team to tailor an adequate positioning plan for each individual case. The early third trimester is the more limiting period because of the womb hindrance favoring lateral or three-quarters positionings.

Effect of a low-dose dexmedetomidine infusion on intraoperative hemodynamics, anesthetic requirements and recovery profile in patients undergoing lumbar spine surgery

Background and Aims

Dexmedetomidine has been used as an anesthetic adjuvant; however, hypotension is a concern especially in prone patients. The aim of the study was to evaluate the effect of a low-dose dexmedetomidine infusion on intraoperative hemodynamics, blood loss, anesthetic requirements, and recovery profile in patients undergoing lumbar spine surgery in the prone position.

Material and Methods

The study was conducted in a randomized double-blinded manner in 60 patients scheduled for one- or two-level lumbar laminectomy. After administration of general anesthesia, patients were placed in prone position and allocated to either of two groups of 30 patients each. Patients in Group A received dexmedetomidine infusion at the rate of 0.3 μg kg^-1 hr^-1, whereas, group B patients received a saline infusion. The depth of anesthesia was guided by Bispectral index (BIS) monitoring, maintaining BIS between 40 and 60.

Results

The demographic profile and duration of surgery in both groups were similar. Mean heart rate was statistically similar in both the groups. Mean blood pressure was lower in group A, though the difference was significant only for the initial 30 min. The mean end-tidal sevoflurane requirement in group A was significantly less than that in group B (P = 0.003). Patients in group A had better recovery profile with mean emergence, extubation, and recovery times of 8.08 ± 3.48 min, 9.37 ± 3.64 min, and 11.65 ± 4.03 min, respectively, as compared with 11.27 ± 3.05 min, 12.24 ± 2.39 min, and 14.90 ± 2.63 min, respectively, in group B (P < 0.001). Mean intraoperative blood loss in group A of 263.47 ± 58.66 mL was significantly lower than 347.67 ± 72.90 ml in group B (P = 0.0001).

Conclusion

Group A patients had stable hemodynamic parameters, reduced intraoperative blood loss, less anesthetic requirement, and could be extubated earlier as compared with group B patients.

COMPARISON OF ENDOSCOPIC AND MICROSURGICAL METHODS IN THE TREATMENT OF LUMBAR DISC HERNIATIONS

ABSTRACT Objective: The development of minimally invasive spine surgery leads us to reflect on the efficiency of new methods compared with older ones. In the case of endoscopic spine surgery, we always seek to compare our results using new techniques with the results of older and trusted microsurgical techniques. Unfortunately, there are few reliable studies measuring endoscopic and microsurgical approaches. We therefore decided to compare our treatment results with those of what are, in our opinion, the best and most thorough studies found. Furthermore, we found no illustrated experience in the usability of endoscopic methods. We therefore analyzed each step of the technique used, according to the practical experience with microsurgical discectomy. Methods: We compared our two-year experience of treatment of 183 patients with lumbar disc herniations using the endoscopic technique, with data reported in the literature on microsurgical minimally invasive methods. Results: Our group achieved good to excellent results in 92.9% of cases (170 patients) compared to 90% reported in the literature. We compared the capabilities of endoscopic discectomy with microsurgical methods, and concluded that the endoscopic method is sufficient to perform any movement inside the surgical field that is microscopically possible. It is also possible to perform any type of spinal cord decompression, with better visualization provided by the endoscope. Conclusions: We conclude that endoscopic microdiscectomy is a good and reliable alternative, with better outcomes and more efficient usage of the approach space.

Intraregional differences of perioperative management strategy for lumbar disc herniation: is the Devil really in the details?

BACKGROUND

This study intends to evaluate whether regional common habits or differences in case-volume between surgeons are significative variables in the perioperative management of patients undergoing surgery for lumbar disc herniation.

METHODS

An e-mail survey was sent to all neurosurgeons working in Lombardy, Italy's most populated region. The survey consisted of 17 questions about the perioperative management of lumbar disc herniation.

RESULTS

Forty-seven percent (47%) out of 206 Lombard neurosurgeons answered the survey. Although in some respects there is clear evidence in current literature on which is the best practice to adopt for an optimal management strategy, we noticed substantial differences between respondents, not only between hospitals but also between surgeons from the same hospital. Still, no differences were evident in a high vs low case-volume comparison.

CONCLUSION

We identified no regional clusterization as for practical principles in the perioperative management of lumbar disc herniation and neither was case-volume a significative variable. Other causes may be relevant in the variability between the perioperative management and the outcomes achieved by different specialists.

The prone position during surgery and its complications: a systematic review and evidence-based guidelines

Surgery in the prone position is often a necessity when access to posterior anatomic structures is required. However, many complications are known to be associated with this type of surgery, as physiologic changes occur with increased pressure to anterior structures. While several studies have discussed postoperative vision loss, much fewer studies with lower levels of evidence have addressed other complications. A systematic literature review was conducted using 2 different databases, and 53 papers were regarded as appropriate for inclusion. Qualitative and quantitative analysis was performed. Thirteen complications were identified. Postoperative vision loss and cardiovascular complications, including hypovolemia and cardiac arrest, had the most number of studies and highest level of evidence. Careful planning for optimal positioning, padding, timing, as well as increased vigilance are evidence-based recommendations where operative prone positioning is required.

Spine Surgery and Blood Loss: Systematic Review of Clinical Evidence

Spine surgery has been growing rapidly as a neurosurgical operation, with an increase of 220% over a 15-year period. Intraoperative blood transfusion is a major outcome determinant of spine procedures. Various approaches, including pharmacologic and nonpharmacologic therapies, have been tested to decrease both intraoperative and postoperative blood loss. The aim of this systematic review is to report clinical evidence on the relationship between intraoperative blood loss (primary outcome) and on transfusion requirements and postoperative complications (secondary outcomes) in patients undergoing spine surgery. A literature search of PubMed database was performed using 5 key words: spine surgery and transfusion; spine surgery and blood loss; spine surgery and blood complications; spine surgery and deep vein thrombosis; and spine surgery and pulmonary embolism. Clinical reports (randomized controlled trials, prospective and retrospective studies, and case reports) were selected. A total of 473 articles were examined; 450 were excluded, and 24 were selected for this systematic review. Selected articles were categorized into 3 subchapters: (1) drugs active on coagulation (12 studies): tranexamic acid, aminocaproic acid, aprotinin, and recombinant activated factor VII; (2) drugs not active on coagulation (5 studies): ketorolac, epoetin alfa, magnesium sulfate, propofol/sevoflurane, and omega-3 and fish oil; (3) nonpharmacologic approaches (7 studies): surgical tips, patient positioning, and general or spinal anesthesia. Several studies have shown a significant reduction in intraoperative bleeding during spine surgery and in the requirement for blood transfusion.

Comparison of the effects of colloid preload, vasopressor administration and leg compression on hemodynamic changes during spinal anesthesia for lumbar disc surgery in knee-chest position

BACKGROUND

Hypotension is a serious and the most common adverse effect of spinal anesthesia. Many studies have focused on prevention of hypotension due to spinal anesthesia. The aim of this study was to compare the efficacy of three different methods of using colloid, ephedrine and wrapping of extremities on the incidence of hypotension and bradycardia following spinal anesthesia in patients undergoing elective lumbar disc surgery in knee-chest position.

MATERIALS AND METHODS

A total of 180, ASA (I-II), adult patients candidate of lumbar disc surgery in one or two levels who met the inclusion criteria were randomly allocated in one of three treatment groups of receiving Voluven (6% hydroxyethyl starch 130/0.4 in 0.9% sodium chloride injection), ephedrine and leg wrapping. After establishment of spinal anesthesia, patients were outsourced and knee-chest position was done. Heart rate and blood pressure of patients were recorded at different times till 60 min after spinal injection. Statistical analyses of data were performed with SPSS (version 20) and by considering groups, values of P < 0.05 were considered statistically significant.

RESULTS

Mean systolic blood pressure (119.5 ± 7.4 mmHg) and mean heart rate (71.7 ± 6.7 b/min) were higher in a group receiving Voluven (P < 0.05). The Voluven group significantly experienced less nausea and vomiting in recovery room in comparing with other groups (P = 0.027). They also received significantly less ephedrine (P = 0.012) and ondansetron [12 (20%)] (P = 0.02). Furthermore, patients receiving elastic bandage had significantly more blood loss than the other groups (P = 0.013).

CONCLUSION

Colloid therapy was the most effective method in keeping hemodynamic stability, prevention of decrease in systolic blood pressure and incidence of side effects during spinal anesthesia for lumbar disc surgery in knee-chest position.

[A comparative analysis of the effectiveness and potential of endoscopic and microsurgical resection of disc herniations in the lumbosacral spine]

The issue of advantage of endoscopic treatment of spinal disc herniations is debatable. Throughout the development, endoscopic technologies have been compared to microsurgical methods. The two-year experience of applying endoscopic methods was analyzed. The study included 183 patients. The effectiveness of the performed treatment was evaluated according to the MacNab scale of surgical treatment outcomes. Good and excellent results were obtained in 170 cases, which amounted to 92.9%. This cure rate was compared to the similar rate for good and excellent results of the microsurgical treatment method derived from the literature data. The article by American authors who conducted a multicenter study (Lumbar microdiscectomy: a historical perspective and current technical considerations. Koebbe C.J., Maroon J.C., Abla A., El-Kadi H., Bost J. Neurosurg Focus 2002 Aug 15; 13(2): E3) was used. On the basis of this study, the data on higher effectiveness of endoscopic discectomy compared to the microsurgical technique were obtained. The technical capabilities of the endoscopic method for removing spinal disc herniations in comparison to minimally invasive microsurgical techniques were carefully analyzed. It was noted that there were no significant instrumental limitations for using endoscopic techniques, while angled optics and excellent color rendition enable better visualization of the surgical wound structures and more efficient use of the approach space. Given that the technical characteristics and capabilities of this method are not inferior to those of the microsurgical technique, the former technology can be used instead of the standard technique for removing intervertebral disc herniations. Furthermore, the technical capabilities of the method allow performing wide decompression of the neural structures during surgery, which can be used to treat spinal stenoses.

[Hepatic artery aneurysm rupture after lumbar stenosis surgery. Medico-legal thinking]

INTRODUCTION

Distinguishing between therapeutic contingency and surgical complication is sometimes not easy, especially when rare events occur. We report the case of a patient who presented with an intraperitoneal haemorrhage following laminectomy and discuss the implications of surgery in this complication.

CASE REPORT

A 77-year-old woman, suffering from radiculopathy due to lumbar stenosis underwent a laminectomy in the prone position. On admission she presented with high blood pressure and obesity as significant comorbidities. A few hours after surgery, she collapsed and underwent a thoraco-abdominal CT-scan. The examination revealed a ruptured hepatic artery aneurysm. It is the first case published in the medical literature after lumbar surgery. The aim of this article was to discuss the responsibility of the surgeon and surgery, particularly the surgical positioning of the ruptured aneurysm.

CONCLUSION

After reviewing the literature we did not find any evidence to attribute the rupture of this hepatic artery aneurysm to lumbar surgery. This adverse event could be attributed to therapeutic contingency. In cases of patient complaint, this situation depends on national solidarity.

Prediction of blood loss during surgery on the lumbar spine with the patient supported prone on the Jackson table

BACKGROUND CONTEXT

To date, many studies have examined the effects of one or several factors on blood loss during lumbar spine surgery. The nature and extent of the operation, patient position, blood pressure, and a variety of factors related to patient size have been touted as predictors of blood loss.

PURPOSE

To measure multiple factors implicated as determinants of blood loss and develop a multivariable statistical model capable of predicting blood loss.

STUDY DESIGN

An observational study of patients undergoing lumbar spine surgery in the prone position on the Jackson table.

PATIENT SAMPLE

A total of 71 healthy adult men and women undergoing lumbar spine surgery in a university hospital setting.

OUTCOME MEASURE

Blood loss during surgery.

METHODS

We observed 35 surgeries and recorded demographic and body habitus data on each patient as well as surgical variables, blood pressure, and peripheral venous pressure. We measured bladder pressure intermittently as a surrogate for intra-abdominal pressure. We constructed a statistical model with the results and validated that model in a separate set of 36 subjects.

RESULTS

The Jackson table supported all our patients regardless of body dimensions without causing an increase in bladder pressure. Blood loss during surgery averaged 1,167±998 mL (mean±1 standard deviation, range 32-3,745). The statistical model was able to account for about 75% of the variability in blood loss using four variables: the number of laminectomies, whether bone was harvested from the iliac crest, experience of the surgeon doing the initial exposure and closure, and distension of the epidural veins. Data on these variables that were collected in the validation study found a multiple correlation coefficient (R(2)) of 0.66 between predicted and observed blood loss.

CONCLUSIONS

This is the first study to build a successful multivariable predictive model of blood loss during spine surgery. The Jackson table was effective in supporting patients with different body sizes and shapes, thus removing raised intra-abdominal pressure as an important factor.

The effect of body mass index on intra-abdominal pressure and blood loss in lumbar spine surgery

Objective

The purpose of this prospective study was to evaluate the effects of body mass index (BMI) on intra-abdominal pressure (IAP) and intraoperative blood loss (IBL) during lumbar spinal surgery.

Methods

Thirty patients scheduled for single level posterior lumbar interbody fusion were allocated equally to a normal group (Group 1, BMI;18.5-22.9 kg/m²), an overweight group (Group 2, BMI; 23-24.9 kg/m²), and an obese group (Group 3, BMI; 25.0-29.9 kg/m²) according to BMI. IAP was measured using a urinary bladder catheter; 1) supine after anesthesia induction, 2) prone at skin incision, 3) prone at the end of surgery. In addition, IBL was also measured in the three groups.

Results

IAP in the supine position was not significantly different in groups 1, 2, and 3 (2.7 mm Hg, 3.0 mm Hg, and 4.2 mm Hg, respectively) (p=0.258), and IAP in the prone position at incision increased to 7.8 mm Hg, 8.2 mm Hg, and 10.4 mm Hg, respectively, in the three groups, and these intergroup differences were significant, especially for Group 3 (p=0.000). IAP at the end of surgery was slightly lower (7.0 mm Hg, 7.7 mm Hg, and 9.2 mm Hg, respectively). IBLs were not significantly different between the three groups. However, IBLs were found to increase with IAP in the prone position (p=0.022) and BMI (p<0.05).

Conclusion

These results show that BMI affects IAP in the prone position more than in the supine position during lumbar spinal surgery. In addition, IBLs were found to increase with IAP in the prone position and with BMI. Thus, IBLs can be expected to be higher in morbidly obese patients due to an increased IAP.

Effects of prone and jackknife positioning on lumbar disc herniation surgery

BACKGROUND

Intra-abdominal hypertension due to surgical position increases bleeding at the surgical site. In this study, we evaluated the impact of prone and jackknife position on intra-abdominal pressure (IAP), lung mechanics, blood loss at the surgical site, and duration of the surgical procedure on lumbar disc operations.

METHODS

Forty patients operated for single-space lumber disc herniation were included in our study. All patients were ASA I-II and 18 to 70 years old. Patients who had undergone previous spinal surgery, were on anticoagulant or anti-aggregant therapy, had hypertension, cardiac, respiratory, liver, or renal disorders, and were obese (Body Mass Index >35 kg/m²) were excluded. Patients were randomly assigned to either the prone or the jackknife position for surgery. Differences in lung mechanics, IAP, and surgical-site blood loss were calculated in both patient groups. Changes in pulmonary and abdominal pressure levels were measured both in face-up and down positions.

RESULTS

Bleeding at the surgical site (prone: 180.0±100.0 mL, jackknife: 100.0±63.6 mL, P=0.018) and IAP (prone: 11.0±3.0 mm Hg, jackknife: 8.0±2.0 mm Hg, P=0.006) were significantly reduced when patients were in the jackknife position. Operating time was approximately 40 minutes shorter in the jackknife position group, although this difference was not significant.

CONCLUSIONS

The jackknife position causes less IAP elevation and less surgical site bleeding compared with the prone position. The jackknife position is the preferred choice for single-level lumbar disc surgery in healthy, nonobese patients.

Prospective assessment of patient morbidity from prone sacral positioning

OBJECT

Sacrectomy positioning must balance surgical exposure, localization, associated operative procedures, and patient safety. Poor positioning may increase hemorrhage, risk of blindness, and skin breakdown.

METHODS

The authors prospectively identified positioning-related morbidity in 17 patients undergoing 19 prone sacral procedures from September 2008 to August 2009 following institution of a standardized positioning protocol. Key elements include skull traction/head suspension, an open radiolucent frame, and wide draping for associated closure and reconstructive procedures.

RESULTS

Tumors included 5 chordomas, 4 high-grade sarcomas, 1 chondrosarcoma, 2 presacral extradural myxopapillary ependymomas, and 5 others. Mean patient age was 49.9 years (range 17-74 years); mean body mass index was 27.6 kg/m(2) (range 19.3-43.9 kg/m(2)). Mean preoperative Braden skin integrity score was 21.1 (range 17-23). Average operative time was 501 minutes (range 158-1136 minutes). Prone surgery was a part of staged anterior/posterior resections in 8 patients. Localization was conducted using fluoroscopy in 13 patients and intraoperative CT in 4 patients. All imaging studies were successful. One patient developed a transient ulnar nerve palsy attributed to positioning. Three patients (two of whom were morbidly obese) developed Stage I pressure injuries to the chest and another developed Stage II pressure injury following a 1136-minute procedure. Morbidity was only observed in patients with morbid obesity or with procedures lasting in excess of 10 hours.

CONCLUSIONS

A positioning protocol using head suspension on an open radiolucent frame facilitates oncological sacral surgery with reasonable patient morbidity. Morbid obesity and procedure times in excess of 10 hours are risk factors for positioning-related complications. To the authors' knowledge, this is the first report of surgical positioning morbidity in this patient population.

Complications in spinal deformity surgery: issues unrelated directly to intraoperative technical skills

STUDY DESIGN

Literature review of complications unrelated directly to surgical skills involved in spinal deformity surgery.

OBJECTIVE

Highlight complications associated with perioperative issues.

SUMMARY OF BACKGROUND DATA

Complications can arise from mundane events that arise during the operative experience, but are not directly related to surgical skills.

METHODS

Literature reviews that touches on the more common potential complication events that do not involve direct surgical expertise.

RESULTS

The topics of positioning, nutrition, blood loss, comorbidities, OR time, and pulmonary and GI concerns are discussed as basics that could derail a surgical outcome even with an otherwise uneventful surgical technique. The need for vigilance is stressed and the nuances of understanding these are discussed.

CONCLUSION

Mundane events can derail a perfectly executed surgical undertaking. Attention to detail, team work, close monitoring, and checklist type focus will help to improve, focus, and avoid these preventable complications that have nothing to do with direct surgical skills.

Lumbar microdiscectomy with spinal anesthesia: comparison of prone and knee-chest positions in means of hemodynamic and respiratory function

STUDY DESIGN

Prospective clinical study to compare the physiologic changes in lumbar disc surgery regarding to positions.

OBJECTIVE

To compare the perioperative hemodynamic and respiratory functions between prone and knee-chest positions for lumbar disc surgery under spinal anesthesia.

SUMMARY OF BACKGROUND DATA

Spinal anesthesia is a safe but rarely used alternative to general anesthesia for lumbar disc surgery. It reduces blood loss, avoid pressure necrosis, and nerve injuries, and it provides a more comfortable postoperative period. Prone and knee-chest positions are mostly used positions in lumbar discectomy; hemodynamic and respiratory effects of spinal anesthesia and the differences between these 2 positions in spinal anesthesia were evaluated in this study, which only been evaluated in general anesthesia.

METHODS

Forty-five patients were randomized for lumbar microdiscectomy with spinal anesthesia under either prone position (group 1 n = 22) or knee-chest position (group 2 n = 23). All patients were classified as physical status 1 or 2 according to the American Association of Anesthesiology. Spinal anesthesia was performed with hyperbaric bupivacaine. Perioperative continuous hemodynamics and respiratory function test results were recorded after the spinal anesthesia was performed.

RESULTS

Immediately after the spinal anesthesia was performed, both the systolic and diastolic arterial blood pressure values were significantly decreased and heart rates were significantly increased in both groups. Both positions showed significant decrease in forced vital capacity (P = 0.002) and forced expiratory volume in 1 second (P = 0.0015) during the surgery respect to preoperative values. The decrease in peak expiratory flow (P = 0.011) and forced expiratory flow at the 25% of the pulmonary volume (P = 0.011) was significant in knee-chest position respect to prone position.

CONCLUSION

In conclusion, spinal anesthesia is appropriate for lumbar disc surgery with respect to the hemodynamic parameters in both prone and knee-chest positions, however, in terms of pulmonary functions, the knee-chest position can cause a restrictive effect. Therefore this position should be used cautiously in higher-risk patients.

Higher risk of dural tears and recurrent herniation with lumbar micro-endoscopic discectomy

Existing studies on micro-endoscopic lumbar discectomy report similar outcomes to those of open and microdiscectomy and conflicting results on complications. We designed a randomised controlled trial to investigate the hypothesis of different outcomes and complications obtainable with the three techniques. 240 patients aged 18-65 years affected by posterior lumbar disc herniation and symptoms lasting over 6 weeks of conservative management were randomised to micro-endoscopic (group 1), micro (group 2) or open (group 3) discectomy. Exclusion criteria were less than 6 weeks of pain duration, cauda equina compromise, foraminal or extra-foraminal herniations, spinal stenosis, malignancy, previous spinal surgery, spinal deformity, concurrent infection and rheumatic disease. Surgery and follow-up were made at a single Institution. A biomedical researcher independently collected and reviewed the data. ODI, back and leg VAS and SF-36 were the outcome measures used preoperatively, postoperatively and at 6-, 12- and 24-month follow-up. 212/240 (91%) patients completed the 24-month follow-up period. VAS back and leg, ODI and SF36 scores showed clinically and statistically significant improvements within groups without significant difference among groups throughout follow-up. Dural tears, root injuries and recurrent herniations were significantly more common in group 1. Wound infections were similar in group 2 and 3, but did not affect patients in group 1. Overall costs were significantly higher in group 1 and lower in group 3. In conclusion, outcome measures are equivalent 2 years following lumbar discectomy with micro-endoscopy, microscopy or open technique, but severe complications are more likely and costs higher with micro-endoscopy.

Uso da câmara de ar em cirurgia ortopédica: aplicações, vantagens e desvantagens

OBJETIVO: o trabalho visou à difundir o uso da câmara de ar, de forma sistemática, em cirurgias ortopédicas, como suporte e protetor das saliências ósseas, em especial nas cirurgias de longa duração. MÉTODOS: trata-se de um estudo prospectivo não randomizado, realizado entre 2002 e 2007, totalizando de 264 procedimentos ortopédicos. RESULTADOS: verificou-se que, independente do tempo de cirurgia, não houve áreas de pressão nas proeminências ósseas ou lesões de nervos periféricos no pós-operatório. CONCLUSÃO: os resultados do presente estudo permitiram recomendar a câmara de ar como uma excelente opção de suporte em cirurgias ortopédicas, pois se trata de um dispositivo de baixo custo, fácil obtenção e alta reprodutibilidade.

Recovery from paraplegia after the treatment of spinal dural arteriovenous fistula: case report and review of the literature

BACKGROUND

Spinal dural arteriovenous fistula (SDAVF) is a rare and enigmatic disease. Functional outcome is particularly uncertain for the small group of patients that are unable to stand at the time of diagnosis (grade 5 gait disturbance on the Aminoff-Logue scale, ALS). The objective of this study is to examine the final functional outcome of patients with SDAVF in grade 5 gait ALS before treatment.

METHODS

We conducted a PubMed search using the keyword "spinal dural arteriovenous fistula." A review of the clinical series and single well-detailed case reports of SDAVF gathered 106 patients with grade 5 gait ALS on the initial examination. Additionally, we report the case of a 56-year-old man presenting acute paraplegia and urinary retention on admission who had complained of sporadic motor and sphincter disturbances for 1 year. Spine T2-weighted MR imaging showed a central hyperintensity within the spinal cord, and the angiography demonstrated a T-11 SDAVF. Interruption of the fistula was performed through an urgent one-level laminectomy.

RESULTS

Grade 5 gait ALS was present in 25% of the patients with SDAVF included in the clinical series. Latest follow-up showed that gait disturbance improved in 73% of patients after treatment, although less than 6% became grade 1 gait ALS. Micturition disturbances improved in 39%. Exploration of our patient showed improvement to grade 1 gait ALS 1 year after the surgical treatment.

CONCLUSION

Interruption of SDAVF in paraplegic patients may improve the final functional gait outcome in some cases. No complete recovery (grade 0 gait ALS) was achieved after treatment. Micturition disturbances had a worse prognosis than motor deficits.

Upper-limb somatosensory evoked potential monitoring in lumbosacral spine surgery: a prognostic marker for position-related ulnar nerve injury

BACKGROUND CONTEXT

Somatosensory evoked potential (SSEP) is used to monitor integrity of the brain, spinal cord, and nerve roots during spinal surgery. It records the electrical potentials from the scalp after electrical stimulation of the peripheral nerves of the upper or lower limbs. The standard monitoring modality in lumbosacral spine surgery includes lower-limb SSEP and electromyography (EMG). Upper-limb SSEP monitoring has also been used to detect and prevent brachial plexopathy and peripheral nerve injury in thoracic and lumbosacral spine surgeries. We routinely monitor lower-limb SSEP and EMG in lumbosacral spine procedures at our institution. However, a few patients experienced postoperative numbness and/or pain in their ulnar distribution with uneventful lower-limb SSEP and EMG.

PURPOSE

We hypothesized that the postoperative upper extremity paresis in lumbosacral surgeries may result from compression and/or stretch of the brachial plexus and/or ulnar nerve while the patients were in prone position. Using upper-limb SSEP, we investigated whether we observe any significant change in the SSEP, and if so, whether we can prevent or reduce frequency of postoperative upper extremity deficits.

STUDY DESIGN/SETTING

In this prospective study, we monitored upper-limb SSEP, in addition to lower-limb SSEP and EMG, in 230 elective, posterior lumbosacral spinal procedures. All operations were performed by a group of four neurosurgeons.

PATIENT SAMPLE

One hundred and thirty-one female and 99 male with an age range of 28 to 86 years between January 2004 and December 2005 were studied.

OUTCOME MEASURES

Amplitude and latency of upper-limb or ulnar SSEP were continuously compared with those of the baseline. A greater than or equal to 50% decrease in SSEPs amplitude and/or a greater than or equal to 10% increase in latency were considered to be significant.

METHODS

After intubation, patients were positioned prone on Jackson or Andrews spinal table. Anesthesia was maintained with inhalant gas (desflurane or sevoflurane) and propofol infusion with and without minimal infusion of narcotics (fentanyl, sufentanyl, or remifentanil). Intraoperative neurophysiologic monitoring of upper-limb or ulnar SSEP was achieved by continuously recording cortical and subcortical responses after alternate stimulation of the ulnar nerve at the wrist. In our institutional protocol, a greater than or equal to 50% decrease in SSEPs amplitude and/or a greater than or equal to 10% increase in latency were considered to be significant to alert the operating surgeons. When significant changes occurred, the surgeon was immediately notified. Also, reevaluation of vital signs, depth of anesthesia, and patient's position, and technical troubleshootings were subsequently followed.

RESULTS

We observed a greater than or equal to 50% decrease in amplitude of ulnar SSEP in 10 patients without significant changes in lower-limb SSEP (peroneal or posterior tibial nerve SSEP) or EMG during surgery. Eight patients had changes in unilateral limbs, and two patients had changes in bilateral limbs. Two patients with significant changes in unilateral limbs showed changes twice. The mean SSEP amplitude for the 14 changes was 29.2+/-3.1% (mean+/-SEM, standard error of mean) of the baseline value at the average surgical time of 60+/-1.5 minutes. With repositioning of the arms, the amplitudes were immediately restored with the average of 70.2+/-7.1% (n=14) of the baseline value. The mean amplitude of upper-limb SSEP was 73.4+/-8.7% (n=12) of the baseline at wound closure. The average surgical time was 154+/-29.2 minutes per case for the 10 patients. There was no documented postoperative upper extremity paresis in all 230 patients.

CONCLUSIONS

The present study demonstrates that upper-limb SSEP monitoring could detect position-related ulnar neuropathy in 5.2% of the patients undergoing lumbosacral spine surgery.