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 Table of Contents  
ORIGINAL ARTICLE
Year : 2020  |  Volume : 34  |  Issue : 3  |  Page : 175-182

Ultrasound-guided transmuscular quadratus lumborum block for anterior iliac crest bone graft promotes early ambulation in patients undergoing cervical corpectomy and fusion


1 Department of Anaesthesia, Christian Medical College, Vellore, Tamil Nadu, India
2 Department of Neurological Sciences, Christian Medical College, Vellore, Tamil Nadu, India
3 Department of Neuroanaesthesia, Christian Medical College, Vellore, Tamil Nadu, India
4 Department of Biostatistics, Christian Medical College, Vellore, Tamil Nadu, India

Date of Submission06-Jul-2020
Date of Decision28-Jul-2020
Date of Acceptance26-Sep-2020
Date of Web Publication28-Dec-2020

Correspondence Address:
Dr. Ramamani Mariappan
Department of Neuroanaesthesia, Christian Medical College, Vellore, Tamil Nadu
India
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/ijpn.ijpn_88_20

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  Abstract 


Context: The iliac crest (IC) is widely used as an autograft for bony fusion in spine surgeries. The pain after IC harvesting is severe enough to delay ambulation and thus hospital discharge. Aim: This study aimed to determine the effect of a transmuscular quadratus lumborum block (QLB) on postoperative ambulation in patients undergoing anterior IC bone graft harvesting. Settings and Design: This was a retrospective study of patients who underwent cervical corpectomy and fusion with anterior IC bone graft over a period of 3 years. Materials and Methods: Group A was patients who received QLB for anterior IC bone graft harvest site pain, and those who did not receive QLB were Group B. The primary outcome was the time taken for ambulation, and the secondary outcomes compared were the pain scores, hemodynamics, and the duration of hospital stay. Results: A total of 34 patients were studied, of which 17 patients received QLB (Group A) and the rest 17 did not receive QLB (Group B). The demographics, preoperative and intraoperative variables, and the pain score were comparable between the groups. The patients in the QLB group ambulated early as compared to Group B (1.5 ± 0.7 vs. 2.4 ± 0.9 days = 0.002). Further, the duration of postoperative hospitalization was shorter in the former as compared to the latter (3.8 ± 1.6 vs. 5.1 ± 2.1 days; P = 0.054). There were no complications related to the QLB. Conclusion: The administration of QLB resulted in earlier postoperative ambulation in patients undergoing cervical corpectomy with AIC bone graft. Although the length of hospitalization was shorter in the QLB group, it was not statistically significant.

Keywords: Analgesia, local anesthetics, nerve block, postoperative pain


How to cite this article:
Pillai R, Nair BR, Prabhakar PK, Singh G, Lionel KR, Moorthy RK, Joy M, Mariappan R. Ultrasound-guided transmuscular quadratus lumborum block for anterior iliac crest bone graft promotes early ambulation in patients undergoing cervical corpectomy and fusion. Indian J Pain 2020;34:175-82

How to cite this URL:
Pillai R, Nair BR, Prabhakar PK, Singh G, Lionel KR, Moorthy RK, Joy M, Mariappan R. Ultrasound-guided transmuscular quadratus lumborum block for anterior iliac crest bone graft promotes early ambulation in patients undergoing cervical corpectomy and fusion. Indian J Pain [serial online] 2020 [cited 2021 Jan 18];34:175-82. Available from: https://www.indianjpain.org/text.asp?2020/34/3/175/305151




  Introduction Top


Cervical spondylotic myelopathy (CSM) is the most common degenerative spine disease in the elderly population, and surgical intervention is often indicated in such patients. The prevalence of surgically treated CSM has been estimated at 1.6 per 100,000 population.[1] Cervical corpectomy is associated with improved functional outcome as compared to anterior cervical discectomy and fusion, laminectomy, and laminoplasty.[1] Uninstrumented cervical corpectomy for a degenerative spine disease mandates the utilization of the anterior iliac crest (IC) or fibular bone graft to facilitate bony fusion. Due to its osteogenic, osteoconductive, and osteoinductive properties, the IC is the favored harvest site for autologous graft placement for a variety of orthopedic and spine procedures.[2] Pain at the IC harvest site adds to the morbidity of the surgical procedure.[3],[4],[5] The degree of pain has been reported to range from moderate to severe, which delays ambulation and, therefore, prolongs the duration of postoperative hospitalization.[2],[3],[4],[5] It thus follows that adequate pain relief after IC harvest will aid in early ambulation.[6]

To provide adequate analgesia, the ventral rami of the subcostal nerve (T12), ilioinguinal (L1), iliohypogastric nerve (L1), and the lateral femoral cutaneous nerve (L2, L3) which innervate the periosteum and the muscles attached to anterior IC require to be blocked.[7],[8] These nerves lie on the ventral surface of the quadratus lumborum muscle before traversing into the muscle layers of the anterior abdominal wall and hence serve as a convenient site for approach.

Various studies have shown that regional analgesia provides superior pain relief, reduces the systemic side effects of analgesic drugs, and improves functional capacity in high-risk patients undergoing major surgeries when compared to those who receive systemic analgesia as the sole modality for pain relief.[9],[10] There are various modes of regional analgesic techniques for managing graft harvest site pain such as transversus abdominis plane (TAP) block,[11] transversalis fascia plane (TFP) block,[12] quadratus lumborum block (QLB),[13] and the continuous infusion of local anesthetics (LA).[14]

Among all the fascial blocks, the QLB is advantageous for several reasons. In QLB, the LA is deposited in the thoracolumbar fascia and produces widespread dermatomal blockade from T9-L5 level, thus covering all the dermatomes with a single-bolus injection as compared to the TAP or TFP, in which the T12 division can be spared.[15] In QLB, the needle trajectory is distant from the peritoneal cavity, visceral abdominal organs, and large blood vessels, and hence, injury to these vital structures is less as compared to the TFP and TAP block. The systemic concentration of LA is significantly less after QLB as compared to the TAP block.[15],[16]

Since 2018, our center has routinely performed QLB for patients undergoing cervical corpectomy and fusion using AIC bone graft. To study the efficacy and safety of QLB, this study compared this technique with those who did not receive QLB. As early postoperative ambulation is deterred by pain at the AIC harvest site, the time to ambulation after extubation was the primary outcome of interest.


  Materials and Methods Top


Ethics, study design, and study population

This retrospective study was conducted after obtaining approval from the Institutional Review Board and Ethics Committee. Patients who underwent cervical corpectomy and fusion with AIC graft between December 2016 and December 2019 were retrospectively studied. Those who received QLB were taken as cases (Group A), and those who did not receive QLB served as controls (Group B). Data were collected from the inpatient hospital and anesthesia records.

Data collection

The baseline demographics, intraoperative opioid requirements, duration of anesthesia and surgery, postoperative hemodynamics, levels of dermatomal blockade (for Group A), pain score using a Numerical Rating Scale (NRS), time taken to ambulate, and length of hospital stay were compared between the groups. The maximum pain score during the first 12 h, 12–24 h, and 24–48 h after surgery was extracted from the inpatient hospital records and compared between the groups. Since the same team of neuroanesthesiologists and a single neurosurgeon were involved, the anesthetic and surgical management was similar between the two groups.

Anesthetic management

Apart from the standard ASA monitoring (NiBP, SPO2, ECG, ETCO2, and temperature), an invasive blood pressure (BP), tracheal cuff pressure monitoring, agent analyzer, and train-of-four-neuromuscular monitoring were placed. All patients were induced with fentanyl (2 μg/kg) and propofol (2–3 mg/kg) and relaxed with vecuronium (0.1–0.15 mg/kg) and intubated with the appropriate size ETT using C-MAC videolaryngoscope. Morphine (0.05–0.1 mg/kg) and paracetamol (20 mg/kg) were administered intravenously for intraoperative analgesia. All patients had an invasive arterial line for maintaining hemodynamics within 20% of baseline as per our routine protocol. At the end of surgery, the residual neuromuscular block was reversed with neostigmine (50 μg/kg) and glycopyrrolate (10 μg/kg). Injection lignocaine (1.5 mg/kg) (preservative free) was given to aid in smooth extubation. The endotracheal tube was removed when the patient met extubation criteria. Postoperatively, all patients received intravenous paracetamol (1 g every 6 hours) for analgesia. If the patients had moderate-to-severe pain (NRS >5), injection pentazocine 30 mg or injection diclofenac 50 mg was given intramuscularly as rescue analgesia.

Quadratus lumborum block technique[16]

All patients in Group A received ultrasound-guided transmuscular QLB with a catheter for postoperative analgesia. The patient was positioned in the right lateral position with the hip and knee in a flexed position. A three-liter glycine bag was placed under the right flank. A curvilinear ultrasound (USG) transducer probe (2–5 MHz) was placed at the midpoint between the edge of the 12th rib and the IC transversely and traced posteriorly, and the probe was tilted cranially and caudally to obtain a proper view of the QL muscle. An 18G Tuohy needle (epidural needle) was introduced from the posterior edge of the curvilinear probe in the anteromedial direction using an in-plane technique (transmuscular approach) [Figure 1]. After confirming the correct needle position, 10–15 ml of LA was deposited in the thoracolumbar fascia between the psoas and the quadratus lumborum muscle. The dipping of psoas muscle indicated correct needle placement in the thoracolumbar fascia [Figure 2]. Once the thoracolumbar fascia opened up, the 20G epidural catheter was placed, and 3–4 cm of the catheter length was threaded cranially from the needle tip. After confirming catheter position, 10–15 ml of LA was injected. The details of the bolus, the volume, and the drug concentration of LA used for the QLB while placing the catheter are summarized in [Table 1]. To prevent catheter migration, it was tunneled subcutaneously and secured away from the surgical site. Subsequent boluses of 0.2% ropivacaine 20–30 ml were administered every 12 hourly for 48 h, after which the catheter was removed. The catheter site was inspected before and after every bolus injection to rule out catheter malposition or signs of infection.
Figure 1: An illustrative diagram showing the site of USG probe placement and the needle direction while performing the transmuscular quadratus lumborum block

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Figure 2: Ultrasound image of transmuscular quadratus lumborum block showing the drug deposition in the thoracolumbar fascia and the dipping of the psoas muscle

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Table 1: Volume and the concentration of drugs used for intraoperative quadratus lumborum block

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Outcomes

The primary outcome measure was the time taken to ambulate from the time of extubation. Ambulation was defined as the ability of a patient to move out of and around the bed, independently or with support (relatives by their side to support them or using a frame for support while moving around the bed). The secondary outcomes measured were the duration of postoperative hospital stay and pain as assessed using the NRS scoring system. The safety of the QLB was evaluated by monitoring the heart rate and BP recordings for 48 h post-QLB. Complications related to QLB were recorded such as local catheter site infection, hematoma, motor blockade, failed blockade, and signs and symptoms of local anesthetic-induced systemic toxicity.

Statistical analysis

All categorical variables were reported using frequencies and percentages. Continuous variables, which follow normality, were reported in terms of mean and standard deviation, and skewed data were reported using median with interquartile range. Student t-test was used to analyze continuous data with normal distribution and Mann–Whitney U-test for data with skewed distribution. Chi-square test was performed for categorical variables. A P < 0.05 was considered statistically significant. The statistical analysis was performed using IBM SPSS Statistical Software for Windows, version 21.0 (Armonk, NY, USA: IBM Corp).


  Results Top


The demographic details, preoperative parameters, clinical presentation, and intraoperative and postoperative parameters were similar between the two groups [Table 2]. The total dose of intraoperative fentanyl and morphine consumption was comparable between the two groups. The number of levels of corpectomy, duration of surgery, and anesthesia were similar and comparable between the two groups.
Table 2: The demographics and the perioperative details

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Quadratus lumborum block characteristics

QLB was performed at the end of the surgical procedure, before extubation in all patients, except one, in whom the block was performed after intubation and before the start of surgery. Patients received either 0.25% bupivacaine (n = 6), 0.375% ropivacaine (n = 4), or 0.2% ropivacaine (n = 7) while performing the block and 0.2% ropivacaine (n = 17) for postoperative bolus. The average volume administered for intraoperative bolus was 30 ± 5.7 ml, and for the postoperative bolus, it was 30 ± 6.24 ml. The interval between the first (intraoperative) and the second (first postoperative) boluses varied between 10 and 12 h. Details of the sensory blockade were recorded in 7 of the 17 patients. These seven patients had T12 to L2-3 sensory dermatomal blockade on the left side. None of the patients had motor blockade or QLB catheter-related complications. One patient had QLB catheter displacement at 36 h, necessitating its removal (at 36 h).

Outcomes

The time to ambulation was earlier in patients in Group A compared to Group B (1.5 ± 0.7 vs. 2.4 ± 0.9 days), which was statistically significant (P = 0.002). The duration of postoperative hospital stay was shorter in patients who received QLB as compared to those who did not receive the block (3.8 ± 1.6 vs. 5.1 ± 2.1 days; P = 0.054). Although it was clinically significant, it was not statistically significant.

Since every bolus administration can spread medially into the paravertebral/epidural space, the hemodynamics (heart rate and blood pressure) were monitored after every bolus. The hemodynamics were comparable between the two groups. The pain score at rest and movement at various time intervals was comparable between the groups [Table 3]. Two patients in Group B received one dose of diclofenac intramuscularly as a rescue analgesic.
Table 3: Maximum Numerical Rating Scale score at rest and movement during 0- 12 h, 12- 24 h, and 24- 48 h of postoperative period

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  Discussion Top


The administration of QLB for the anterior IC harvest site pain aided in early ambulation and reduced the duration of postoperative hospitalization in patients undergoing cervical corpectomy and fusion with an anterior IC bone graft. To date, there has been only one study that had reported the usefulness of QLB for IC harvest site pain.[13] We have done a literature search on the role of the various interfascial blocks for postoperative analgesia at IC harvest site pain. The summary of the result is provided in [Table 4]. Most studies analyzed the levels of the dermatomal blockade at the time of performing the block,[8],[13] pain score,[8],[11],[17],[18] mean opioid consumption,[12],[18] and the incidence of chronic pain[8],[12] as primary outcomes.
Table 4: The demographics, the surgery, the type of interfascial block, the outcomes, and conclusion of various studies on interfascial plane blocks performed for iliac graft site pain

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Till date, no studies looked at the time to ambulation and the length of hospital stay as a primary outcome in patients who received interfascial block for analgesia for this surgery. In a prospective observational study, Saikrishna et al.[6] have compared the ambulation time (20 patients; 10 in each group) after the continuous infusion of 0.25% bupivacaine into the IC wound using an epidural catheter with the administration of single-shot infiltration and found that the continuous infusion helped in early ambulation (2.3 vs. 3.2 days). They attributed this difference to the analgesic effect. In our study, the intraoperative and the postoperative managements were similar between the two groups except for the administration of QLB. Hence, we attribute the early ambulation to adequate analgesia provided by the QLB. Following the success, we have evidenced in our patients; this has become the analgesic standard of care in our institution for this surgical procedure.

Early ambulation following surgery is beneficial in patients undergoing spine surgery as it reduces the incidence of deep vein thrombosis, pulmonary embolism, and other pulmonary complications and decreases the length of hospitalization.[19] A retrospective study by Stuart Green et al.[20] had shown that the QLB reduced the length of hospital stay and the intraoperative fentanyl consumption in patients undergoing total hip arthroplasty. Our study also had shown that the length of the hospitalization time was less (3.8 ± 1.6 vs. 5.1 ± 2.1 days) in the QLB group. Although it was clinically significant, it was not statistically significant; this could be due to the small sample size.

The study being retrospective in nature, it was not possible to extract the pain score for all patients at all time points. Hence, we had collected the maximum pain score, which was recorded in the chart between the time points of 0–12 h, 12–24 h, and 24–48 h. The pain score was comparable between the groups. The clinical study by Sondekoppam et al.[13] had shown that, despite achieving a satisfactory dermatomal blockade with LAs, three out of four patients had a high NRS score ranging between 5 and 8, indicating the subjective nature of pain assessment. Black et al.[12] compared the average pain score at 0–24 h and 24–48 h after TFP block with placebo. They had concluded that the pain score was comparable (1.5 vs. 3, 1.5 vs. 3.5) between the groups despite the significant decrease in analgesic consumption in patients who received block. Similar to the studies mentioned above, our research also had shown that the pain score was comparable between the groups.

The shorter time to ambulation and the decreased duration of hospitalization indicates that the QLB provided effective analgesia for anterior IC pain. Our study has shown that the QLB provided a unilateral (left) sensory blockade from T12-L3 or L1-L3. This is in contrast to the experience reported by Sondekoppam et al.[13] wherein they demonstrated T9-L2 dermatomal anesthesia following injection of 20 ml of LA. The speed of LA injection (20 ml over 10 s) could have resulted in a wider dermatomal blockade in their study as compared to our study, in which the 20–30 ml of LA was injected slowly over a period of 2–3 min (6 vs. 3–4 levels of the dermatomal blockade).

Since the USG-guided transmuscular QLB was performed or guided by the anesthesiologist who is familiar with this regional block, the success rate of the block was very high, and there were no complications noted in our series related to QLB.[21] One patient in the QLB group had graft displacement for which re-exploration was done. Although this may not be related to QLB placement, the practice of placing the QLB catheter at the beginning of surgery rather at the end of the surgery was followed in order to avoid turning the patient to lateral decubitus position immediately after placement of graft into the corpectomy defect.

In this study, three different concentrations of LA were used for the intraoperative bolus injection. During the evolution of QLB techniques, initially, we had used high concentration (>0.25%) and high volume (40 ml) of LA to improve the success of the block later, as we had refined our technique, only 20–30 ml of 0.2% ropivacaine for intraoperative bolus followed by 20 ml of 0.2% ropivacaine for postoperative analgesia.

Some studies have reported the hemodynamic instability associated with the bolus injection in QLB.[22],[23] This could be due to the possibility of the spread of LA into the paravertebral space or sympathetic trunk.[15] However, none of our patients had hemodynamic instability after every bolus injection; this could be due to the slow rate of injection (20–30 ml over a period of 2–3 min).

Limitations

The smaller number of patients studied and the retrospective nature of the study are the limitations of our study.


  Conclusion Top


The administration of QLB resulted in early postoperative ambulation in patients undergoing cervical corpectomy with anterior IC bone graft. Although the length of hospitalization was only clinically shorter in the QLB group, further randomized control trials, comparing different interfascial blocks and involving a larger number of patients, will serve to confirm this finding.

Acknowledgment

We acknowledge the help of Aniketh Prabhu. K, Medical student, CMC Vellore, for the illustrative diagram of the QLB block [Figure 1].

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
  References Top

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Williams KE, Paul R, Dewan Y. Functional outcome of corpectomy in cervical spondylotic myelopathy. Indian J Orthop 2009;43:205-9.  Back to cited text no. 1
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Pollock R, Alcelik I, Bhatia C, Chuter G, Lingutla K, Budithi C, et al. Donor site morbidity following iliac crest bone harvesting for cervical fusion: A comparison between minimally invasive and open techniques. Eur Spine J 2008;17:845-52.  Back to cited text no. 2
    
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