- Email: [email protected]
Lumbar microdiscectomy under epidural anaesthesia with the patient in the sitting position: A prospective study
Journal of Clinical Neuroscience 17 (2010) 1537–1540
Contents lists available at ScienceDirect
Journal of Clinical Neuroscience journal homepage: www.elsevier.com/locate/jocn
Clinical Study
Lumbar microdiscectomy under epidural anaesthesia with the patient in the sitting position: A prospective study Nicola Nicassio a,⇑, Paolo Bobicchio a, Marzia Umari b, Leonello Tacconi a a b
Neurosurgery Department, University Hospital, Ospedali Riuniti di Trieste, Strada di fiume 447, Trieste 34149, Italy ARTA Department, University Hospital, Ospedali Riuniti di Trieste, Trieste, Italy
a r t i c l e
i n f o
Article history: Received 11 December 2009 Accepted 4 April 2010
Keywords: Lumbar disc surgery Sitting position Spinal anaesthesia
a b s t r a c t In a prospective study we compared the surgical outcome, length of hospital stay, complications and patient satisfaction for patients undergoing lumbar microdiscectomy (LM) under spinal anaesthesia (SA) in the sitting position (23 patients) to those of another cohort who underwent LM under general anaesthesia (GA) in the prone or genu-pectoral position during the same time period (238 patients). We aimed to determine: (i) if epidural anaesthesia is safe for lumbar microdiscectomy; and (ii) if placing the patient in a sitting position confers an advantage in performing the operation. For all patients we calculated the time from the end of the operation to the first spontaneous urination and to the first administration of analgesic drugs. Before being discharged, patients were asked to give an opinion on the quality of analgesia obtained by epidural anaesthesia and on the sitting position used. No patient had any complications linked to epidural anaesthesia and only one patient experienced a small dural tear as a surgical complication. Twenty of 23 patients expressed satisfaction with the level of analgesia obtained and only three considered it poor. All patients found the sitting position comfortable. Advantages of the sitting position for surgery include better comfort for the patient, potential to recreate a load condition similar to the one that takes place during orthostasis and a ‘‘cleaner” operative field that uses gravity to drain blood. Of greatest concern is the possibility of the patient developing a dural tear and subsequent leaking of cerebrospinal fluid, which could also be a source of surgical complications. Currently, epidural anaesthesia allows a reduction in anaesthetic and surgical times, anaesthetic complications and, consequently, hospitalization period. Further analysis of the sitting position for the patient during surgery is required to fully assess the advantages and disadvantages of this method. Ó 2010 Elsevier Ltd. All rights reserved.
1. Introduction Surgery for lumbar disc prolapse is one of the most common spinal procedures. Lumbar microdiscectomy (LM) is usually performed under general anaesthesia (GA) even though a recent publication based on a randomized study of 100 patients showed no differences between GA and spinal anaesthesia (SA) for LM,1 and some authors have previously highlighted the utility of SA for LM2,3 with both groups of authors concluding that SA is as safe and effective as GA.2,3 In addition, SA can reduce some of the risks present with GA, as well as the length of inpatient stay and overall costs. In June 2006 we began a prospective pilot study in which we used SA in 24 selected patients who underwent LM, with the patient placed in the sitting position. We compared the results (surgical outcome, length of hospital stay, complications and patient satisfaction) obtained for this group with those of another cohort
⇑ Corresponding author. Tel.: +39 347 1843 012; fax: +39 040 399 4285. E-mail address: [email protected] (N. Nicassio). 0967-5868/$ - see front matter Ó 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.jocn.2010.04.031
that underwent LM under GA in the prone position during the same time period. 2. Materials and methods After obtaining approval from the Ethics Committee, we carried out a prospective preliminary study from June 2006 to May 2008. During this period, 262 patients with lumbar disc prolapse were admitted to our department for an LM (male to female ratio = 1:7). The mean age of patients was 51 (range = 19–82). On the basis of the neurosurgical and anaesthetic criteria summarized in Table 1, 24 patients were selected for a microdiscectomy under SA in the sitting position. Two groups of patients were studied; group A comprised 238 patients, who underwent LM under GA in the prone or genu-pectoral position, and group B comprised 24 patients who underwent surgery for the same pathology under SA in the sitting position. One of the patients in group B experienced severe myofascial pain and subsequently this patient underwent their surgery under GA; accordingly, this patient was excluded from the study. There-
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N. Nicassio et al. / Journal of Clinical Neuroscience 17 (2010) 1537–1540
Table 1 Criteria for selection of patients undergoing microdiscectomy under spinal anaesthesia in the sitting position (group B) Neurosurgical criteria
Anaesthetic criteria
Single lumbar space involvement Soft disc prolapsed No previous surgical procedure on lumbar spine
No allergy to anaesthetic medications No skin infection at injection site No hypovolaemia or fixed cardiac output states (additive risks with sympathetic block)
Common criteria for anaesthesiology and neurosurgery Age younger than 50 Patient consent and cooperation No coagulopathy or therapeutic anticoagulation No anatomical abnormalities of vertebral column
fore, group B comprised 23 patients with a male:female ratio of 1:4 and a mean age of 37 years (range: 26–48 years). In this group, 19 of 23 disc prolapses were small or medium in size and only four patients had large disc prolapses. Disc prolapse was unilateral in all patients: 14 on the left and 9 on the right. Table 2 shows both groups of patients divided on the basis of their lumbar disc involvement. 2.1. Procedure for spinal anaesthesia In order to standardize our SA, the same steps were followed for each patient; while monitoring cardiac (electrocardiogram, heart rate and blood pressure) and respiratory parameters (respiratory rate, SpO2), 3 mg of midazolam was administered intravenously. The patient was placed in the sitting position and the correct intervertebral space was identified (generally two spaces above the prolapsed disc). After local anaesthesia with 5 mL of lidocaine 2%, a peridural needle (17 gauge 3–7/8”TW) was introduced on the midline and the epidural space was identified with the ‘‘air syringe technique”. Subsequently, 8–10 mL (depending on the body mass index of the patient) of ropivacaine 0.75% was administered in ‘‘one shot”. The patient remained in the sitting position for a further 30 minutes. 2.2. Surgical procedure
The surgical procedure lasted, on average, 44 minutes (min) (range = 36–72 min), approximately 20 min less (range = 48– 112 min) than LM under GA. After the procedure the patient was brought directly back to the ward on a wheelchair, without spending time in the recovery room. 3. Results None of the patients experienced any complications related to the SA. From a surgical point of view, the only complication we observed in group B was one patient who developed a small dural tear (4.3%). In group A a dural tear occurred in seven of 238 patients (2.9%) while other complications included superficial wound infection of the surgical site (eight patients, 3.4%) and discitis (three patients, 1.3%). For all patients operated under SA, we calculated the period of time elapsed from the end of the operation until the first spontaneous urination as well as until the first administration of analgesic drugs. Patients were able to pass urine spontaneously 3–7 hours after the operation (mean = 4.5 hours) and analgesic drugs were administered after 6–25 hours (mean = 12 hours). The mean duration of hospitalization differed between the two groups: 44 hours (range: 1–9 days) for group A and 30 hours (range: 1–7 days) for group B. Before being discharged, group B patients were asked to rate the quality of analgesia obtained by SA and how comfortable the sitting position was during the operation. Twenty of 23 patients considered epidural anaesthesia effective and satisfactory for pain control and three patients considered it poor. Two of these patients reported pain during the nerve root retraction which required administration of additional local anesthetics. The third patient reported pain during disc removal. All patients found the sitting position comfortable and stressed a common opinion that watching a movie during surgery had made the overall experience less stressful (Table 3). In group B, the duration of follow-up lasted from 8 to 30 months (mean = 11 months). Two of 23 patients were lost to long-term follow-up (although at 3 and 6 months both reported a clear benefit). None of the other patients, followed up for a longer period, experienced a relapse of their symptoms or any other kind of complication. 4. Discussion
After inducing SA, the patient was positioned on a surgical table in the sitting position (Fig. 1) and the surgical procedure was performed in the same way as for LM under GA. After checking the correct disc space with a C-arm fluoroscope, a 3 cm midline skin incision was made. The length of this incision was about 1 cm longer when compared with the group A patients. A retractor for the paravertebral muscles was inserted and ligamentum flavum resection and a partial laminectomy were performed as required. All procedures were conducted under the operating microscope. During the procedure, patients were encouraged to relax by watching a movie on a screen placed in front of them.
Table 2 Lumbar disc involved for patients undergoing microdiscectomy either under spinal anaesthesia in the sitting position (Group B) or under general anaesthesia in the prone or genu-pectoral position (Group A) Disc space
Group A
Group B
L1–L2 L2–L3 L3–L4 L4–L5 L5–S1
2 9 37 107 83
0 0 3 11 9
LM is one of the most frequently performed operations worldwide. Results are generally related to the correct indication for operation rather than to the anaesthetic or surgical technique used.2 Minimally invasive techniques are preferred by some surgeons as they appear to correlate with a smaller quantity of post-operative fibrosis.4 LM is usually performed under GA, with the patient in a prone or genu-pectoral position. Currently, GA is used routinely; it is preferred by anaesthesiologists because it allows standard monitoring of vital parameters of the patient, and by surgeons because it allows extension of the operating time for teaching purposes without problems. Also, GA is often preferred by patients because it can avoid the anxiety linked to the awareness of undergoing a surgical operation and the fear of feeling pain.2,3,5–7 However, GA also has some drawbacks that should be considered including pulmonary complications, injuries from peripheral nerve compression during patient positioning, postoperative nausea and vomiting and extension of the operative time related to patient awakening and recovery.3,8 Currently, only a few centers perform LM under SA. Our prospective study analyzed two different issues: the utility of SA in performing an LM and the use of the sitting position for the patient during this procedure. Our results validate the use of SA and support prior publications.7,9 This study shows that SA is as safe and
N. Nicassio et al. / Journal of Clinical Neuroscience 17 (2010) 1537–1540
1539
Fig. 1. Dedicated surgical table used for the sitting position. This figure is available in colour at www.sciencedirect.com.
Table 3 Satisfaction of patients who underwent microdiscectomy under spinal anaesthesia in the sitting position (Group B)
Excellent Fair Poor
Satisfaction for analgesia
Satisfaction for sitting position
15 5 3
18 5 0
effective as GA and it also reduces the surgical and anesthetic times and, consequently, the risks related to GA. In 87% of patients in our study, analgesia level was considered adequate, and often the only pain sensation the patient reported was a ‘‘feeling of pressing.” Generally analgesia was sufficient such that patients did not feel pain during nerve root manipulation. Three exceptions (13%) were noted. The first two patients reported discomfort during the procedure. Of these two, the second, who was affected by a partially calcified L4–L5 disc prolapse, reported that his real discomfort came from the noise of the drill. This negative experience, which occurred at the beginning of our study, led us to slightly increase the concentration of anesthetic medications used to induce SA. The third patient reported pain during disc removal, which we speculate was due to stimulation of the vertebral plate’s nociceptors. This patient had reported opioid abuse in his medical history and, therefore, it is possible that past use of these substances resulted in his being less responsive to medication used for SA. This was easily managed by inducing a light sedation with propofol. Reduction of anaesthetic time required for SA occurs as a result of eliminating the wake-up time that is necessary after GA; it is also unnecessary to monitor the patient during the post-operative
period.2,5,8,10 Reduction of surgical time seems largely related to easier positioning of the patient and to a reduction of intra-operative bleeding. The latter point is the result of multiple determinants. The sympatholytic effects of anaesthetic drugs used for SA, which are responsible for vasodilatation and mild hypotension, reduces the amount of intra-operative bleeding. In addition, the lack of the increased intrathoracic pressure that normally occurs when the patient is in the prone position contributes to less venous bleeding.8 At our center, the overall reduction inoperative time gave us the opportunity to perform a greater number of surgical procedures in the same operating day. With respect to the usefulness of SA, two other factors were considered: the onset of spontaneous urination and the pain-free period after the operation. In the past, urinary retention was typically considered a side effect of SA more than of GA.5 In our study, none of the patients had difficulty in urination after the operation and it was never necessary to insert a bladder catheter. As observed by other authors, it is possible that this difference is related to the failure to use opioids for induction of the SA.5,8 The extension of the pain-free period after SA is likely due to the fact that the nerve fibers for protopathic sensation (Ad and C) responsible for pain transmission are more susceptible to the medications used for SA and resume their function more slowly than the fibers for motility and epicritic sensation.6–8 In group B, analgesic drugs were requested, on average, 12 hours after the end of the operation, suggesting a longer lasting pain control. Generally, the incidence of post-operative nausea or vomiting in patients who undergo SA is considerably lower than in patients who undergo GA, for whom sometimes these side effects can last for more than 24 hours. In our study, no patients in the SA group had post-operative nausea
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or vomiting and all patients successfully ate a meal a few hours after the operation. The SA patients had no complications with the exception of one patient with a dural tear (who was kept in bed longer than usual); the remainder of the patients in this group began to ambulate few hours later and were discharged home, on average, 30 hours after the operation. A final point to note is that during operations under SA we experienced a slight difficulty in the placement of the muscle retractor, because of lack of muscle relaxation, which required increasing the length of the skin incision of about 1 cm. The second point we assessed in our study was the use of the sitting position for the patient during the operation. The sitting position, compared to the prone or lateral position, has benefits and drawbacks. Advantages include better comfort for the patient and the recreation of loading conditions similar to those that take place in the upright posture, which is often when symptoms are worsened. This allows identification of borderline herniations, in which nerve root compression takes place only in upright posture, as has been shown by MRI.11 Furthermore, the sitting position gives a cleaner, less bloody operative field, because the blood flows out under gravity. A disadvantage of this position is the discomfort for the surgeon who, even if seated, has to operate with outstretched arms with the operating microscope in a position similar to that used during posterior fossa surgery. This disadvantage, however, is somewhat mitigated by the shorter operating time. The most worrying drawback of the sitting position, which could also result in dangerous complications, is the possibility of a dural tear with a subsequently worse CSF leak. In our series, a dural tear occurred in only one patient and the situation was easily managed with compression with SurgicelÒ Fibrillar Absorbable Hemostat (Ethicon; New Brunswick, NJ, USA) and primary closure with 3.0 non-resorbable stitches. While a small dural tear (as in our patient) may have no effect, a larger one could cause a profound CSF leak, with a consequent risk of intracranial complications. For this reason, we selected patients who did not have any factors (such as previous surgery on the involved disc space, presence of scar tissue involving the dura, radiation therapy on lumbar spine) in their medical history that could increase the risk of a dural tear.
5. Conclusion Although the surgical result of LM is largely related to the correct medical indication, our prospective study, while limited in its statistical value by the small sample size and by its design, highlights how SA can be effective and safe to perform LM in selected patients. Compared to GA, SA may allow a reduction in anaesthetic and surgical times, in anaesthetic complications and consequently in hospitalization period. It is possible that the technique could allow this type of surgery to be performed as day procedure. We advise further analysis of the sitting position with a randomized study to further assess the risks and benefits. References 1. Sadrolsadat SH, Mahdavi AR, Moharari RS, et al. A prospective randomized trial comparing the technique of spinal and general anesthesia for lumbar disk surgery: a study of 100 cases. Surg Neurol 2009;71:60–5. 2. Smrcka M, Baudysová O, Jurán V, et al. Lumbar disc surgery in regional anaesthesia–40 years of experience. Acta Neurochir (Wien) 2001;143:377–81. 3. Papadopoulos EC, Girardi FP, Sama A, et al. Lumbar microdiscectomy under epidural anesthesia: a comparison study. Spine J 2006;6:561–4. 4. Koebbe CJ, Maroon JC, Abla A, et al. Lumbar microdiscectomy: a historical perspective and current technical considerations. Neurosurg Focus 2002;13:1–6. 5. Jellish WS, Thalji Z, Stevenson K, et al. A prospective randomized study comparing short- and intermediate-term perioperative outcome variables after spinal or general anesthesia for lumbar disk and laminectomy surgery. Anesth Analg 1996;83:559–64. 6. McLain RF, Kalfas I, Bell GR, et al. Comparison of spinal and general anesthesia in lumbar laminectomy surgery: a case-controlled analysis of 400 patients. J Neurosurg Spine 2005;2:17–22. 7. McLain RF, Tetzlaff JE, Bell GR, et al. Microdiscectomy: spinal anesthesia offers optimal results in general patient population. J Surg Orthop Adv 2007;16:5–11. 8. McLain RF, Bell GR, Kalfas I, et al. Complications associated with lumbar laminectomy: a comparison of spinal versus general anesthesia. Spine 2004;29:2542–7. 9. Demirel CB, Kalayci M, Ozkocak I, et al. A prospective randomized study comparing perioperative outcome variables after epidural or general anesthesia for lumbar disc surgery. J Neurosurg Anesthesiol 2003;15:185–92. 10. Dagher C, Naccache N, Narchi P, et al. Regional anesthesia for lumbar microdiscectomy. J Med Liban 2002;50:206–10 [In French]. 11. Zou J, Yang H, Miyazaki M, et al. Dynamic bulging of intervertebral discs in the degenerative lumbar spine. Spine 2009;34:2545–50.
Contents lists available at ScienceDirect
Journal of Clinical Neuroscience journal homepage: www.elsevier.com/locate/jocn
Clinical Study
Lumbar microdiscectomy under epidural anaesthesia with the patient in the sitting position: A prospective study Nicola Nicassio a,⇑, Paolo Bobicchio a, Marzia Umari b, Leonello Tacconi a a b
Neurosurgery Department, University Hospital, Ospedali Riuniti di Trieste, Strada di fiume 447, Trieste 34149, Italy ARTA Department, University Hospital, Ospedali Riuniti di Trieste, Trieste, Italy
a r t i c l e
i n f o
Article history: Received 11 December 2009 Accepted 4 April 2010
Keywords: Lumbar disc surgery Sitting position Spinal anaesthesia
a b s t r a c t In a prospective study we compared the surgical outcome, length of hospital stay, complications and patient satisfaction for patients undergoing lumbar microdiscectomy (LM) under spinal anaesthesia (SA) in the sitting position (23 patients) to those of another cohort who underwent LM under general anaesthesia (GA) in the prone or genu-pectoral position during the same time period (238 patients). We aimed to determine: (i) if epidural anaesthesia is safe for lumbar microdiscectomy; and (ii) if placing the patient in a sitting position confers an advantage in performing the operation. For all patients we calculated the time from the end of the operation to the first spontaneous urination and to the first administration of analgesic drugs. Before being discharged, patients were asked to give an opinion on the quality of analgesia obtained by epidural anaesthesia and on the sitting position used. No patient had any complications linked to epidural anaesthesia and only one patient experienced a small dural tear as a surgical complication. Twenty of 23 patients expressed satisfaction with the level of analgesia obtained and only three considered it poor. All patients found the sitting position comfortable. Advantages of the sitting position for surgery include better comfort for the patient, potential to recreate a load condition similar to the one that takes place during orthostasis and a ‘‘cleaner” operative field that uses gravity to drain blood. Of greatest concern is the possibility of the patient developing a dural tear and subsequent leaking of cerebrospinal fluid, which could also be a source of surgical complications. Currently, epidural anaesthesia allows a reduction in anaesthetic and surgical times, anaesthetic complications and, consequently, hospitalization period. Further analysis of the sitting position for the patient during surgery is required to fully assess the advantages and disadvantages of this method. Ó 2010 Elsevier Ltd. All rights reserved.
1. Introduction Surgery for lumbar disc prolapse is one of the most common spinal procedures. Lumbar microdiscectomy (LM) is usually performed under general anaesthesia (GA) even though a recent publication based on a randomized study of 100 patients showed no differences between GA and spinal anaesthesia (SA) for LM,1 and some authors have previously highlighted the utility of SA for LM2,3 with both groups of authors concluding that SA is as safe and effective as GA.2,3 In addition, SA can reduce some of the risks present with GA, as well as the length of inpatient stay and overall costs. In June 2006 we began a prospective pilot study in which we used SA in 24 selected patients who underwent LM, with the patient placed in the sitting position. We compared the results (surgical outcome, length of hospital stay, complications and patient satisfaction) obtained for this group with those of another cohort
⇑ Corresponding author. Tel.: +39 347 1843 012; fax: +39 040 399 4285. E-mail address: [email protected] (N. Nicassio). 0967-5868/$ - see front matter Ó 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.jocn.2010.04.031
that underwent LM under GA in the prone position during the same time period. 2. Materials and methods After obtaining approval from the Ethics Committee, we carried out a prospective preliminary study from June 2006 to May 2008. During this period, 262 patients with lumbar disc prolapse were admitted to our department for an LM (male to female ratio = 1:7). The mean age of patients was 51 (range = 19–82). On the basis of the neurosurgical and anaesthetic criteria summarized in Table 1, 24 patients were selected for a microdiscectomy under SA in the sitting position. Two groups of patients were studied; group A comprised 238 patients, who underwent LM under GA in the prone or genu-pectoral position, and group B comprised 24 patients who underwent surgery for the same pathology under SA in the sitting position. One of the patients in group B experienced severe myofascial pain and subsequently this patient underwent their surgery under GA; accordingly, this patient was excluded from the study. There-
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N. Nicassio et al. / Journal of Clinical Neuroscience 17 (2010) 1537–1540
Table 1 Criteria for selection of patients undergoing microdiscectomy under spinal anaesthesia in the sitting position (group B) Neurosurgical criteria
Anaesthetic criteria
Single lumbar space involvement Soft disc prolapsed No previous surgical procedure on lumbar spine
No allergy to anaesthetic medications No skin infection at injection site No hypovolaemia or fixed cardiac output states (additive risks with sympathetic block)
Common criteria for anaesthesiology and neurosurgery Age younger than 50 Patient consent and cooperation No coagulopathy or therapeutic anticoagulation No anatomical abnormalities of vertebral column
fore, group B comprised 23 patients with a male:female ratio of 1:4 and a mean age of 37 years (range: 26–48 years). In this group, 19 of 23 disc prolapses were small or medium in size and only four patients had large disc prolapses. Disc prolapse was unilateral in all patients: 14 on the left and 9 on the right. Table 2 shows both groups of patients divided on the basis of their lumbar disc involvement. 2.1. Procedure for spinal anaesthesia In order to standardize our SA, the same steps were followed for each patient; while monitoring cardiac (electrocardiogram, heart rate and blood pressure) and respiratory parameters (respiratory rate, SpO2), 3 mg of midazolam was administered intravenously. The patient was placed in the sitting position and the correct intervertebral space was identified (generally two spaces above the prolapsed disc). After local anaesthesia with 5 mL of lidocaine 2%, a peridural needle (17 gauge 3–7/8”TW) was introduced on the midline and the epidural space was identified with the ‘‘air syringe technique”. Subsequently, 8–10 mL (depending on the body mass index of the patient) of ropivacaine 0.75% was administered in ‘‘one shot”. The patient remained in the sitting position for a further 30 minutes. 2.2. Surgical procedure
The surgical procedure lasted, on average, 44 minutes (min) (range = 36–72 min), approximately 20 min less (range = 48– 112 min) than LM under GA. After the procedure the patient was brought directly back to the ward on a wheelchair, without spending time in the recovery room. 3. Results None of the patients experienced any complications related to the SA. From a surgical point of view, the only complication we observed in group B was one patient who developed a small dural tear (4.3%). In group A a dural tear occurred in seven of 238 patients (2.9%) while other complications included superficial wound infection of the surgical site (eight patients, 3.4%) and discitis (three patients, 1.3%). For all patients operated under SA, we calculated the period of time elapsed from the end of the operation until the first spontaneous urination as well as until the first administration of analgesic drugs. Patients were able to pass urine spontaneously 3–7 hours after the operation (mean = 4.5 hours) and analgesic drugs were administered after 6–25 hours (mean = 12 hours). The mean duration of hospitalization differed between the two groups: 44 hours (range: 1–9 days) for group A and 30 hours (range: 1–7 days) for group B. Before being discharged, group B patients were asked to rate the quality of analgesia obtained by SA and how comfortable the sitting position was during the operation. Twenty of 23 patients considered epidural anaesthesia effective and satisfactory for pain control and three patients considered it poor. Two of these patients reported pain during the nerve root retraction which required administration of additional local anesthetics. The third patient reported pain during disc removal. All patients found the sitting position comfortable and stressed a common opinion that watching a movie during surgery had made the overall experience less stressful (Table 3). In group B, the duration of follow-up lasted from 8 to 30 months (mean = 11 months). Two of 23 patients were lost to long-term follow-up (although at 3 and 6 months both reported a clear benefit). None of the other patients, followed up for a longer period, experienced a relapse of their symptoms or any other kind of complication. 4. Discussion
After inducing SA, the patient was positioned on a surgical table in the sitting position (Fig. 1) and the surgical procedure was performed in the same way as for LM under GA. After checking the correct disc space with a C-arm fluoroscope, a 3 cm midline skin incision was made. The length of this incision was about 1 cm longer when compared with the group A patients. A retractor for the paravertebral muscles was inserted and ligamentum flavum resection and a partial laminectomy were performed as required. All procedures were conducted under the operating microscope. During the procedure, patients were encouraged to relax by watching a movie on a screen placed in front of them.
Table 2 Lumbar disc involved for patients undergoing microdiscectomy either under spinal anaesthesia in the sitting position (Group B) or under general anaesthesia in the prone or genu-pectoral position (Group A) Disc space
Group A
Group B
L1–L2 L2–L3 L3–L4 L4–L5 L5–S1
2 9 37 107 83
0 0 3 11 9
LM is one of the most frequently performed operations worldwide. Results are generally related to the correct indication for operation rather than to the anaesthetic or surgical technique used.2 Minimally invasive techniques are preferred by some surgeons as they appear to correlate with a smaller quantity of post-operative fibrosis.4 LM is usually performed under GA, with the patient in a prone or genu-pectoral position. Currently, GA is used routinely; it is preferred by anaesthesiologists because it allows standard monitoring of vital parameters of the patient, and by surgeons because it allows extension of the operating time for teaching purposes without problems. Also, GA is often preferred by patients because it can avoid the anxiety linked to the awareness of undergoing a surgical operation and the fear of feeling pain.2,3,5–7 However, GA also has some drawbacks that should be considered including pulmonary complications, injuries from peripheral nerve compression during patient positioning, postoperative nausea and vomiting and extension of the operative time related to patient awakening and recovery.3,8 Currently, only a few centers perform LM under SA. Our prospective study analyzed two different issues: the utility of SA in performing an LM and the use of the sitting position for the patient during this procedure. Our results validate the use of SA and support prior publications.7,9 This study shows that SA is as safe and
N. Nicassio et al. / Journal of Clinical Neuroscience 17 (2010) 1537–1540
1539
Fig. 1. Dedicated surgical table used for the sitting position. This figure is available in colour at www.sciencedirect.com.
Table 3 Satisfaction of patients who underwent microdiscectomy under spinal anaesthesia in the sitting position (Group B)
Excellent Fair Poor
Satisfaction for analgesia
Satisfaction for sitting position
15 5 3
18 5 0
effective as GA and it also reduces the surgical and anesthetic times and, consequently, the risks related to GA. In 87% of patients in our study, analgesia level was considered adequate, and often the only pain sensation the patient reported was a ‘‘feeling of pressing.” Generally analgesia was sufficient such that patients did not feel pain during nerve root manipulation. Three exceptions (13%) were noted. The first two patients reported discomfort during the procedure. Of these two, the second, who was affected by a partially calcified L4–L5 disc prolapse, reported that his real discomfort came from the noise of the drill. This negative experience, which occurred at the beginning of our study, led us to slightly increase the concentration of anesthetic medications used to induce SA. The third patient reported pain during disc removal, which we speculate was due to stimulation of the vertebral plate’s nociceptors. This patient had reported opioid abuse in his medical history and, therefore, it is possible that past use of these substances resulted in his being less responsive to medication used for SA. This was easily managed by inducing a light sedation with propofol. Reduction of anaesthetic time required for SA occurs as a result of eliminating the wake-up time that is necessary after GA; it is also unnecessary to monitor the patient during the post-operative
period.2,5,8,10 Reduction of surgical time seems largely related to easier positioning of the patient and to a reduction of intra-operative bleeding. The latter point is the result of multiple determinants. The sympatholytic effects of anaesthetic drugs used for SA, which are responsible for vasodilatation and mild hypotension, reduces the amount of intra-operative bleeding. In addition, the lack of the increased intrathoracic pressure that normally occurs when the patient is in the prone position contributes to less venous bleeding.8 At our center, the overall reduction inoperative time gave us the opportunity to perform a greater number of surgical procedures in the same operating day. With respect to the usefulness of SA, two other factors were considered: the onset of spontaneous urination and the pain-free period after the operation. In the past, urinary retention was typically considered a side effect of SA more than of GA.5 In our study, none of the patients had difficulty in urination after the operation and it was never necessary to insert a bladder catheter. As observed by other authors, it is possible that this difference is related to the failure to use opioids for induction of the SA.5,8 The extension of the pain-free period after SA is likely due to the fact that the nerve fibers for protopathic sensation (Ad and C) responsible for pain transmission are more susceptible to the medications used for SA and resume their function more slowly than the fibers for motility and epicritic sensation.6–8 In group B, analgesic drugs were requested, on average, 12 hours after the end of the operation, suggesting a longer lasting pain control. Generally, the incidence of post-operative nausea or vomiting in patients who undergo SA is considerably lower than in patients who undergo GA, for whom sometimes these side effects can last for more than 24 hours. In our study, no patients in the SA group had post-operative nausea
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or vomiting and all patients successfully ate a meal a few hours after the operation. The SA patients had no complications with the exception of one patient with a dural tear (who was kept in bed longer than usual); the remainder of the patients in this group began to ambulate few hours later and were discharged home, on average, 30 hours after the operation. A final point to note is that during operations under SA we experienced a slight difficulty in the placement of the muscle retractor, because of lack of muscle relaxation, which required increasing the length of the skin incision of about 1 cm. The second point we assessed in our study was the use of the sitting position for the patient during the operation. The sitting position, compared to the prone or lateral position, has benefits and drawbacks. Advantages include better comfort for the patient and the recreation of loading conditions similar to those that take place in the upright posture, which is often when symptoms are worsened. This allows identification of borderline herniations, in which nerve root compression takes place only in upright posture, as has been shown by MRI.11 Furthermore, the sitting position gives a cleaner, less bloody operative field, because the blood flows out under gravity. A disadvantage of this position is the discomfort for the surgeon who, even if seated, has to operate with outstretched arms with the operating microscope in a position similar to that used during posterior fossa surgery. This disadvantage, however, is somewhat mitigated by the shorter operating time. The most worrying drawback of the sitting position, which could also result in dangerous complications, is the possibility of a dural tear with a subsequently worse CSF leak. In our series, a dural tear occurred in only one patient and the situation was easily managed with compression with SurgicelÒ Fibrillar Absorbable Hemostat (Ethicon; New Brunswick, NJ, USA) and primary closure with 3.0 non-resorbable stitches. While a small dural tear (as in our patient) may have no effect, a larger one could cause a profound CSF leak, with a consequent risk of intracranial complications. For this reason, we selected patients who did not have any factors (such as previous surgery on the involved disc space, presence of scar tissue involving the dura, radiation therapy on lumbar spine) in their medical history that could increase the risk of a dural tear.
5. Conclusion Although the surgical result of LM is largely related to the correct medical indication, our prospective study, while limited in its statistical value by the small sample size and by its design, highlights how SA can be effective and safe to perform LM in selected patients. Compared to GA, SA may allow a reduction in anaesthetic and surgical times, in anaesthetic complications and consequently in hospitalization period. It is possible that the technique could allow this type of surgery to be performed as day procedure. We advise further analysis of the sitting position with a randomized study to further assess the risks and benefits. References 1. Sadrolsadat SH, Mahdavi AR, Moharari RS, et al. A prospective randomized trial comparing the technique of spinal and general anesthesia for lumbar disk surgery: a study of 100 cases. Surg Neurol 2009;71:60–5. 2. Smrcka M, Baudysová O, Jurán V, et al. Lumbar disc surgery in regional anaesthesia–40 years of experience. Acta Neurochir (Wien) 2001;143:377–81. 3. Papadopoulos EC, Girardi FP, Sama A, et al. Lumbar microdiscectomy under epidural anesthesia: a comparison study. Spine J 2006;6:561–4. 4. Koebbe CJ, Maroon JC, Abla A, et al. Lumbar microdiscectomy: a historical perspective and current technical considerations. Neurosurg Focus 2002;13:1–6. 5. Jellish WS, Thalji Z, Stevenson K, et al. A prospective randomized study comparing short- and intermediate-term perioperative outcome variables after spinal or general anesthesia for lumbar disk and laminectomy surgery. Anesth Analg 1996;83:559–64. 6. McLain RF, Kalfas I, Bell GR, et al. Comparison of spinal and general anesthesia in lumbar laminectomy surgery: a case-controlled analysis of 400 patients. J Neurosurg Spine 2005;2:17–22. 7. McLain RF, Tetzlaff JE, Bell GR, et al. Microdiscectomy: spinal anesthesia offers optimal results in general patient population. J Surg Orthop Adv 2007;16:5–11. 8. McLain RF, Bell GR, Kalfas I, et al. Complications associated with lumbar laminectomy: a comparison of spinal versus general anesthesia. Spine 2004;29:2542–7. 9. Demirel CB, Kalayci M, Ozkocak I, et al. A prospective randomized study comparing perioperative outcome variables after epidural or general anesthesia for lumbar disc surgery. J Neurosurg Anesthesiol 2003;15:185–92. 10. Dagher C, Naccache N, Narchi P, et al. Regional anesthesia for lumbar microdiscectomy. J Med Liban 2002;50:206–10 [In French]. 11. Zou J, Yang H, Miyazaki M, et al. Dynamic bulging of intervertebral discs in the degenerative lumbar spine. Spine 2009;34:2545–50.