Tendon elongation with bovine pericardium (Tutopatch®) when conventional strabismus surgery is not possible

The use of lyophilized bovine pericardium (Tutopatch®) in the management of third nerve palsy following prior conventional strabismus surgery - a case series

To study the secondary management of strabismus due to third nerve palsy using bovine pericardium (Tutopatch®) when previous conventional surgical therapy had failed. Review of our clinic records of selected patients with third nerve palsy, in whom residual deviation had been managed using Tutopatch® after previous surgical correction. The squint angle was measured preoperatively, and at 1 day, 3 months, and if possible 6 months postoperatively. Nine patients were enrolled in this study. One patient had mainly residual vertical deviation and was corrected with tendon elongation of the contralateral superior rectus. Three patients were operated on with tendon elongation of the lateral rectus muscle with or without medial rectus muscle resection and/or advancement (Group 1). Lateral rectus splitting after tendon elongation in addition to the resection and/or advancement of the medial rectus was performed in five patients with complete third nerve palsy (Group 2). In Group 1, the preoperative median squint angle was -20° (range -17° to -25°), which improved postoperatively to -4.5° (range -12° to +3°). In Group 2, the preoperative horizontal and vertical median squint angles were -27° (range -20° to -40°) and 0.5° (range 0° and 20°), respectively. Postoperatively, they had improved to -12.5° (range-2° to -25°), and 1.5° (range 0° to 7°), respectively. Two patients of Group 2 were re-operated due to residual exotropia. No postoperative complications were observed in any patient. In this small series several complex re-do situations of patients with third nerve palsy were evaluated in which Tutopatch® markedly improved outcomes after an initially ineffective surgical management. For better evaluation of its usefulness a study with more patients is recommended.

Acellular bovine pericardium as a biological dressing for treatment of cutaneous wounds of the distal limb in donkeys (Equus Asinus)

This research was performed to determine the impact of repeated topical dressing with acellular bovine pericardium (ABP) on healing distal limb wounds in donkeys. Twelve male clinically healthy donkeys were subjected to general anesthesia, and full-thickness wounds of six cm2 (2 × 3 cm) were created on the middle dorsolateral surface of the metacarpi. Two defects were made on each donkey’s forelimbs; the right limb was considered a control wound, and the left one was considered a treated wound. Moreover, the control wounds were irrigated with saline every three days postoperatively and bandaged with a standard dressing. The treated wounds were covered with ABP dressings. The ABP dressing was reapplied thrice at 7-, 14- and 21-days post-wound induction. In addition, the wound healing process was monitored clinically, histopathologically, and immunohistochemically of tissue as growth factor-β1, epidermal growth factor receptor, and vascular endothelial growth factor. Besides, the gene expression profile of angiogenic and myofibroblastic genes was applied as vascular endothelial growth factor-A, collagen type 3α1, fibroblast growth factor 7, and the transforming growth factor-β1.

The results revealed that the wounds treated with ABP healed more quickly than the control wounds. Additionally, the mean days required for healing were significantly shorter in the ABP-treated wounds (p < 0.05; 69.5 ± 1.6) compared to control wounds (86.3 ± 3). Furthermore, immunohistochemical and gene expression analyses were significantly improved in ABP wounds than in control wounds. In conclusion, ABP is considered a natural biomaterial and promotes the healing of distal limb wounds in donkeys if applied weekly during the first three-week post-wound induction.

Tendon elongation with bovine pericardium in strabismus surgery-indications beyond Graves' orbitopathy

BACKGROUND

For some patients with complex ocular motility disorders, conventional strabismus surgery is insufficient. Surgery with tendon elongation allows correction of larger angles and maintains a sufficient arc of contact for rectus muscles. This study reports results for tendon elongation with bovine pericardium (Tutopatch®) in indications other than Graves' orbitopathy in which it is already widely used.

METHODS

We reviewed the records of all patients who underwent surgery with Tutopatch® in our institution. Angles of squint and head postures were analyzed preoperatively, on the first postoperative day, and in the long term (median 9 weeks after the operation). Patients with Graves' orbitopathy were excluded.

RESULTS

From 2011 to 2018, the procedures on 58 eyes of 54 patients (35 females, median age 35 years (3-75)) met the inclusion criteria. Horizontal rectus muscle surgery (53 eyes) was conducted on patients with residual strabismus (13), Duane's retraction syndrome with eso- (type I: 16)/exodeviation (type II: 2, type III: 1), 6th (7)/3rd nerve palsy (7), Möbius syndrome (2), congenital fibrosis of the extraocular muscles type 3A (CFEOM3A, TUBB3 mutation) (4), and orbital apex syndrome (1). Vertical rectus muscle surgery (5 eyes) was conducted on patients with myasthenia (1), vertical tropia after orbital floor fracture (1), CFEOM1 (2), and Parry-Romberg syndrome (1). 42 eyes had prior eye muscle surgery (1-5 procedures, median 1). Out of 45 patients with postoperative long-term data, 43 showed an angle reduction. Fifty-one percent had an angle of 10Δ (prism diopter) or less, one had a significant over-effect, and 10 had revision surgery. For the heterogeneous group of residual eso- and exotropias, the median absolute horizontal angle was reduced from 35Δ (16 to 45Δ) to 9Δ (0 to 40Δ), for Duane's retraction syndrome from 27.5Δ (9 to 40Δ) to 7Δ (0 to 40Δ), and for sixth and third nerve palsies from 43Δ (20 to 75Δ) to 18Δ (4 to 40Δ). For 3 patients with vertical rectus muscle surgery, the median absolute vertical angle was reduced from 30Δ (20 to 45Δ) to 4Δ (1 to 22Δ). The motility range was shifted in the direction contrary to the elongated muscle in all subgroups. A considerable reduction of the excursion into the field of action of the elongated muscle had to be registered.

CONCLUSIONS

Strabismus surgery with bovine pericardium introduces new surgical options for complicated revisions and for rare and complex oculomotor dysfunctions. Yet, it has to be recognized that this type of surgery aiming at maximum effects, despite preservation or restitution of the arc of contact, leads to reduction of the excursion into the field of action of the elongated muscle. Furthermore, dose finding can be difficult depending on the underlying pathology and more than one intervention might be necessary for optimal results.

Lateral Rectus Muscle Tendon Elongation by an Auto Graft from the Resected Medial Rectus Muscle as a Monocular Surgery for Large-Angle Sensory Exotropia

PURPOSE

To evaluate using the resected medial rectus muscle for elongation of the lateral rectus tendon in monocular surgery for large-angle sensory exotropia.

PATIENTS AND METHODS

A prospective case series was carried out in Tanta University hospital from January 2017 to June 2018 including 16 patients with large-angle sensory exotropia ≥50PD. The near and distance angles of exotropia were measured; any restrictions in adduction or abduction were recorded and scaled from -4 to 0. Resection of the medial rectus muscle was done first; the resected segment was attached to the lateral rectus muscle after dissection by mattress sutures, and the muscle was recessed after elongation according to the preoperative distance angles. Successful motor alignment was considered if the angle measurement was within 10 PD of orthotropia at distance after 6 months. The stability of the alignment, any motility restrictions, and patient satisfaction were recorded at each follow-up visit until the 6th month.

RESULTS

The mean age of the study patients was 30.68±13.30 years. The best-corrected visual acuity of the exotropic eyes by logMAR was 1.2±0.3; the mean of the preoperative distance angle of deviation was -72.19 ±14.26 PD. The mean preoperative adduction and abduction restrictions were -1.19 ±1.52 and -1.13 ±1.09, respectively. There was significant improvement in the distance angle of deviation at the last follow-up after 6 months (p=0.001*). Also, there was improvement in both adduction and abduction restriction from the first to last follow-up. Thirteen patients (81.2%) were satisfied at the 6-month follow-up.

CONCLUSION

Elongation of the lateral rectus muscle by an autograft from the resected medial rectus muscle is an easy, effective procedure for large-angle sensory exotropia. Patients achieve good postoperative alignment with minimal restriction of ocular motility.

Clinical evidence supporting the use of donor sclera as spacer material in complicated cases of strabismus surgery - retrospective evaluation of surgical results in 117 patients with thyroid-associated ophthalmopathy or congenital strabismus

PURPOSE

To examine the outcome of the use of donor sclera as spacer material in complicated cases of strabismus surgery.

METHODS

A retrospective cohort study on patients with complicated thyroid-associated ophthalmopathy (TAO) (n = 42) or congenital strabismus (n = 75). Patients underwent strabismus surgery during 1994-2014. The surgical results were evaluated in terms of the reduction in the angle of deviation, the need for re-operation, complications and patient satisfaction.

RESULTS

The majority of the TAO patients underwent surgery for vertical strabismus (n = 25). The vertical angle of deviation in the primary position was significantly reduced from a median of 23 prism dioptres (PD) to 2 PD (n = 35, p < 0.001). The horizontal angle of deviation in primary position for TAO patients with esotropia was significantly reduced, from a median of 35 PD to 2 PD (n = 17, p < 0.001). The majority of the congenital cases had horizontal strabismus (esotropia = 29, exotropia = 27). The angle of deviation in esotropia was reduced from a median of 29 PD to 8 PD (n = 36, p < 0.001) and in exotropia from 30 PD to 10 PD (n = 34, p < 0.001). Most of the patients were satisfied with the outcome of surgery, and only 12% required re-operation within 2 years.

CONCLUSION

This is the first clinical study on the use of donor sclera as spacer material in complicated cases of strabismus surgery. The surgical results were good in terms of the reduction in the angle of deviation, the need for re-operation, complications and patient satisfaction, supporting the use of donor sclera for strabismus surgery.

Donor sclera versus bovine pericardium as patch graft material in glaucoma implant surgery and the impact of a drainage suture

Purpose

To compare the use of human donor sclera with bovine pericardium as patch graft material for a glaucoma drainage device (GDD), with respect to the incidence of tube exposure, and to study the role of a drainage suture.

Methods

All GDD surgeries between 2010 and 2014 performed at the VU Medical Center were examined in this comparative, retrospective cohort study. A total of 244 cases were included; 163 in the human donor sclera cohort and 81 in the bovine pericardium cohort with a median follow‐up of 31 and 36 months, respectively. The primary outcome measure was occurrence of tube exposure. Survival analysis for tube exposure was carried out and Kaplan–Meier curves compared. Secondary outcomes were postoperative intraocular pressure (IOP), number of glaucoma medications and the effect of a drainage suture.

Results

In the bovine pericardium cohort, eleven (13.6%) eyes developed tube exposure compared to none in the human donor sclera cohort. Their Kaplan–Meier survival curves differed significantly from each other (χ² = 21.1, p < 0.001, log‐rank test). Mean IOP and number of glaucoma medications did not differ significantly between patch graft materials at three months of follow‐up. The use of a drainage suture directly lowered IOP after surgery in both cohorts. Within the bovine pericardium cohort, eyes with a drainage suture experienced more tube exposure, although this difference was not statistically significant (p = 0.09).

Conclusion

Human donor sclera leads to less tube exposure than bovine pericardium. A drainage suture directly lowers IOP after surgery. With bovine pericardium, but not with donor sclera, exposure tends to be enhanced by a drainage suture.

Medial Rectus Tendon Elongation with Bovine Pericard (Tutopatch®) in Thyroid-Associated Orbitopathy: A Long-Term Follow-Up including Oculodynamic MRI

Introduction

To assess long-term efficacy of bimedial rectus tendon elongation with Tutopatch in thyroid-associated orbitopathy (TAO).

Materials and Methods

Retrospective chart review of 5 patients with TAO undergoing bimedial rectus recession with Tutopatch tendon elongation between 2009 and 2015. We analyzed horizontal squint angles, motility, field of binocular single vision, dose effect of surgery, and when possible oculodynamic MRI (OD-MRI). Dose effect and motility were compared to 4 TAO patients with conventional bimedial recession.

Results and Discussion

In the Tutopatch group, preoperative angles ranged from 14 to 120∆ (prism diopters) at distance and 12–120∆ at near. Mean dose effect was 3.63∆/mm for the distance and 3.43∆/mm for the near angle. All patients were orthotropic at final FU (ranging from 1 to 10 years). OD-MRI showed the elasticity of Tutopatch. In the conventional recession group, preoperative angles ranged between 18 and 35∆ at distance and 12–33∆ at near. At final FU, 2 patients had reverted to their underlying microesotropia <2∆, 1 patient was orthophor, and one was reoperated for a remaining esotropia of 14∆. Dose effect was 2.95∆/mm for the distance and 2.18∆/mm for the near angle. Motility improved in both groups even after 3 months.

Conclusions

Dose effect for medial rectus recessions with Tutopatch in TAO was higher than previously reported, presenting a good alternative to treat large squint angles while preserving good motility.

Decellularised conjunctiva for ocular surface reconstruction

Conjunctival reconstruction is an integral component of ocular surface restoration. Decellularised tissues are frequently used clinically for tissue engineering. This study identifies porcine decellularised conjunctiva (PDC) and human decellularised conjunctiva (HDC) as promising substitutes for conjunctival reconstruction. PDC and HDC were nearly DNA-free, structurally intact and showed no cytotoxic effects in vitro, which was confirmed by DNA quantification, histology, transmission electron microscopy, collagen quantification and cytotoxicity assay. Comparing the biomechanical properties to amniotic membrane (AM), the most frequently applied matrix for ocular surface reconstruction today, the decellularised conjunctiva was more extensible and elastic but exhibited less tensile strength. The in vivo application in a rabbit model proofed significantly enhanced transplant stability and less suture losses comparing PDC and HDC to AM while none of the matrices induced considerable inflammation. Ten days after implantation, all PDC, 4 of 6 HDC but none of the AM transplants were completely integrated into the recipient conjunctiva with a partially multi-layered epithelium. Altogether, decellularised conjunctivas of porcine and human origin were superior to AM for conjunctival reconstruction after xenogeneic application in vivo.

STATEMENT OF SIGNIFICANCE

Conjunctival integrity is essential for a healthy ocular surface and clear vision. Its reconstruction is required in case of immunological diseases, after trauma, chemical or thermal burns or surgery involving the conjunctiva. Due to limitations of currently used substitute tissues such as amniotic membrane, there is a need for the development of new matrices for conjunctival reconstruction. Decellularised tissues are frequently applied clinically for tissue engineering. The present study identifies porcine and human decellularised conjunctiva as biocompatible and well tolerated scaffolds with superior integration into the recipient conjunctiva compared to amniotic membrane. Decellularised conjunctiva depicts a promising substitute for conjunctival reconstruction in ophthalmology.