The use of subtenon ropivacaine in managing strabismus with adjustable sutures

The quest for effective pain control during suture adjustment after strabismus surgery: a study evaluating supplementation of 2% lidocaine with 0.4% ropivacaine

Purpose

To determine whether the addition of 0.4% ropivacaine to the standard 2% lidocaine peribulbar anesthetic block improves pain scores during suture adjustment in patients undergoing strabismus surgery with adjustable sutures.

Methods

Prospective, double-blind study of 30 adult patients aged 21–84 years scheduled for elective strabismus surgery with adjustable sutures. Patients were divided into two groups of 15 patients each based on the local anesthetic. Group A received 2% lidocaine and Group B received 2% lidocaine/0.4% ropivacaine. Pain was assessed using the visual analog scale (VAS) preoperatively and at 2, 4, and 6 hours postoperatively. The Lancaster red-green test was used to measure ocular motility at the same time points.

Results

The pain scores in the two groups were low and similar at all measurement intervals. The VAS for Group A versus Group B at 2 hours (1.7 versus 2.4, P=0.5) and 4 hours (3.5 versus 3.7, P=0.8) showed no benefit from the addition of ropivacaine. At 6 hours, the VAS (3.7 versus 2.7) was not statistically significant, but the 95% confidence interval indicated that ropivacaine may provide some benefit. A repeated measures ANOVA did not find a statistically significant difference in VAS scores over time (P=0.9). In addition, the duration of akinesia was comparable in both groups (P=0.7).

Conclusion

We conclude that the 50:50 mixture of 2% lidocaine with 0.4% ropivacaine as compared to 2% lidocaine in peribulbar anesthetic blocks in adjustable-suture strabismus surgery does not produce significant improvements in pain control during the postoperative and adjustment phases. In addition, ropivacaine did not impair return of full ocular motility at 6 hours, which is advantageous in adjustable-suture strabismus surgery.

Selection of patients and results of 25 years of topical anesthesia and adjustable suture surgery

BACKGROUND AND PURPOSE

The author has used adjustable suture techniques either in the operating room with topical anesthesia or at a later time after retrobulbar or general anesthesia for over 25 years. Careful selection of patients is essential to the success of this technique. It is the purpose of this paper to report the selection criteria used and to compare the results of the two methods utilized.

PATIENTS AND METHODS

One hundred eighty-three patients were included in this study: 123 were operated upon with topical anesthesia. For comparison, sixty patients were included who had adjustment later in the day or the next day after having retrobulbar or general anesthesia. Both horizontal and vertical strabismus cases were included.

RESULTS

Adjustable techniques done in the operating room or at a later time have both shown significant improvement in the strabismus angle following one operation in 86% of the cases. Diplopia was eliminated in 63% of patients with this complaint. (63% and 64.5% in the two groups, respectively). Seventeen of 123 patients having topical anesthesia (13.8%) required a second operation, and 8 of 60 (13.3%) of those having a later adjustment needed further surgery.

CONCLUSION

Careful selection of patients undergoing strabismus surgery allows successful topical muscle adjustment in the operating room with results similar to adjustments done following retrobulbar or general anesthesia at a later time.

Sub-Tenon's ropivacaine block for pain relief after primary strabismus surgery

PURPOSE

Pain is the main cause of patient distress/dissatisfaction after strabismus surgery. The aim of the study was to evaluate the effect of sub-Tenon's block with ropivacaine at the end of strabismus surgery on post-operative pain.

METHODS

A prospective trial was conducted in 79 patients (age 1.0-65 years) scheduled for outpatient primary strabismus surgery with fixed sutures under general anesthesia (GA) at a major tertiary hospital. Half the patients were randomly allocated to receive sub-Tenon's block with ropivacaine 0.2% at conclusion of the operation. Primary outcome measures were visual analog scale (VAS) scores at arrival to the post-anesthesia care unit (PACU), at discharge 3 hr later, 12-16 hr post-operatively, and 24 hr post-operatively. Supplemental analgesia requirements and patient satisfaction were recorded as well. Data were presented as median (range). Mann-Whitney test, Pearson chi(2)-test or Fisher's exact test was used for statistical analysis; p <or= 0.05 was considered significant.

RESULTS

There were no between-group differences in median VAS scores at arrival to the PACU and at discharge, with a borderline difference at 24 hr post-operatively (p = 0.06). At 12-16 hr post-operatively, the median score was 0.0 (range 0-5) in the study group and 4.0 (range 0-6) in the controls (p < 0.001). The lower VAS score in the study group was associated with a lower rate of supplemental analgesia use (21.9% versus 57.9%, p = 0.001), fewer doses of supplemental analgesia (10 doses versus 35, p = 0.03), and higher patient satisfaction (p < 0.001).

CONCLUSIONS

Sub-Tenon's block with ropivacaine 0.2% at the completion of outpatient primary strabismus surgery with fixed sutures under GA reduces pain 12-16 hr post-operatively and analgesia requirements 4-23 hr post-operatively.

Comparison of the stability of postoperative alignment in sensory exotropia: adjustable versus non-adjustable surgery

Purpose

To compare the success rates and stabilities of postoperative alignment between adjustable and the non-adjustable surgeries in the treatment of sensory exotropia.

Methods

A retrospective analysis was performed on all patients with sensory exotropia who had undergone unilateral lateral rectus recession and medial rectus resection (R&R) between January 1998 and August 2005. Thirty-four patients underwent conventional R&R, and 20 patients underwent R&R with adjustable suture of the lateral rectus. The surgical results between the two groups were analyzed with regard to the preoperative and post-operative deviation angles and the postoperative drift. The postoperative deviation angle was measured on postoperative day 1 as well as at two weeks, three months, six months and the final visit after surgery.

Results

There were no statistically significant differences in the mean preoperative and postoperative deviation angles between the two groups. In 30 (88%) patients in the non-adjustable group and 15 (75%) patients in the adjustable group, postoperative deviation was less than 15 prism diopters (PD) at the three month follow-up. There was no significant difference in the mean postoperative drift between the two groups.

Conclusions

Strabismus surgery with adjustable sutures did not show a significantly better result than surgery without adjustable sutures in the treatment of sensory exotropia. Considering the amount of postoperative exodrift in both groups, we postulate that the immediate ocular alignment after surgery for sensory exotropia should be orthophoric or 5-6 PD of esodeviation.

Adjustable suture strabismus surgery in infants and children

PURPOSE

To evaluate the success rate of adjustable suture techniques in horizontal eye muscle surgery in children aged 10 years and younger.

METHODS

A retrospective review of children who had horizontal eye muscle surgery at or before the age of 10 years. Patients were divided into 1 of 2 groups according to whether a nonadjustable or an adjustable technique was used. The preoperative measurements, type of strabismus, and postoperative results were analyzed.

RESULTS

A total of 98 cases in the nonadjustable group and 298 cases in the adjustable group were identified. Early success rate, defined as alignment within 8(Delta) of straight at the end of 3 months, was notably greater in the adjustable group (79%) than in the nonadjustable group (64.5%). The difference was statistically significant (p < 0.01). In the adjustable group, adjustment was performed in 64% of the cases, either because of an undercorrection or overcorrection. The adjustment procedure was performed under topical proparacaine in 20% of cases and under intravenous propofol in 80%. No complications were reported during the adjustment procedure.

CONCLUSIONS

The use of adjustable sutures can provide an improved success rate over nonadjustable sutures in eye muscle surgery in children aged 10 years or younger.

Strabismus surgery under augmented topical anesthesia

PURPOSE

Recently, topical lidocaine 2% jelly had been used in phacoemulsification and trabeculectomy surgeries. The purpose of this study is to evaluate the efficacy and stability of one-stage adjustable suture using topical lidocaine jelly 2% in combination with intravenous nalbuphine (Nubain).

METHODS

Forty adult patients aged 16 to 46 years (median, 24 years) underwent adjustable rectus muscle surgery under topical lidocaine jelly 2% and intravenous 10 mg nalbuphine given 10 minutes before surgery. Adjustment was performed on the operating table before conjunctival closure. The stability of adjustment was studied by comparing the postadjustment deviation to that at 1 day, 1 week, and 3 weeks postoperatively. Success was defined as alignment within 10 prism diopters on distant fixation. Analgesia was assessed using Verbal Description Scale. Changes in vital signs were recorded during surgery to evaluate the oculocardiac reflex.

RESULTS

Forty rectus muscles were recessed, 22 muscles were resected, 3 muscles were tucked, and 2 muscles were retrieved. During the operation, 35 patients expressed no pain, 3 patients complained of discomfort, and 2 patients complained of distressing pain and required an additional 10 mg of intravenous nalbuphine. Thirty-eight patients (95%) were successfully aligned during the first postoperative day, 37 patients (92.5%) after 1 week, and 36 patients (90%) after 3 weeks. Intraoperative cardiac monitoring did not record positive oculocardiac reflex in any patient.

CONCLUSION

Lidocaine jelly in combination with intravenous nalbuphine is an effective topical anesthesia strategy that provides for the patient's comfort and the surgeon's ability to fine-tune ocular alignment on the operating table.

Adjustable sutures in children using a modified technique

PURPOSE

Adjustable-suture techniques are commonly used to decrease the reoperation rate in adults undergoing strabismus surgery, but they are infrequently used in children because of the difficulty of performing adjustments on a conscious child. The purpose of this study is to evaluate a new technique for using adjustable sutures in children, which makes the second stage of the procedure unnecessary if no adjustment is needed.

METHODS

This was a retrospective study of children who underwent surgery for exotropia or esotropia. The technique used was a variation of the standard fornix-based adjustable suture with a separate slipknot. The pole sutures were buried within the sclera and tied; then the incision of the conjunctiva was closed to cover the adjustable sutures. The patients were then measured 4 to 6 hours after the initial surgery. The decision of whether to adjust was based on predetermined criteria. Those children not adjusted were discharged with no further manipulation needed because the conjunctiva was already closed. For those children who were adjusted, the adjustment was made with the patient under intravenous propofol sedation or laryngeal mask anesthesia.

RESULTS

A total of 61 consecutive children ages 12 months to 14 years underwent surgery using this technique. Patients were followed-up after surgery for a minimum of 6 weeks (median 19.4). Fifty-four of the 61 patients (88%) were within 10 prism diopters (PD) of orthophoria on their final postoperative visit. Of the 22 patients who underwent an adjustment, 20 (91%) were within 10 PD of orthophoria at their final postoperative visit. The median follow-up was 19.4 weeks (range 6 to 45.9).

CONCLUSIONS

This new adjustable-suture technique was associated with excellent short-term eye alignment. It is particularly suited for pediatric surgery because it eliminates the necessity of further manipulation of children who do not require adjustment.