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Background:  We newly developed a muscle graft that employs a doxorubicin pretreatment technique. The aims of this study were to reveal the biological and morphological features of the muscle tissue in the second week (Study I), to reveal the regeneration outcomes of functional and kinematic assessments of longer-term follow-up (16 weeks, Study II), and to make assessments of the muscle graft with doxorubicin pretreatment in the critical-sized nerve defect model (20 mm, Study III)., Methods:  A total of 26 adult rats were used in this study. Doxorubicin treatment was accomplished by immersion in a doxorubicin solution for 10 minutes followed by a rinsing procedure. The rats were divided into three groups: the muscle graft with and without doxorubicin pretreatment (M-graft-w-Dox and M-graft-w/o-Dox) groups and the autologous nerve graft (N-graft) group. Assays of apoptosis, immunofluorescent histochemistry including CD68 (macrophage marker), scanning electron microscopy (SEM), morphometrical studies of the regenerated axons, nerve conduction studies, and kinematic studies were performed., Results:  The M-graft-w-Dox group contained significantly larger numbers of apoptotic cells and CD68-positive cells. SEM revealed the existence of the basal lamina, so called "empty tubes," in the M-graft-w-Dox group. Study II showed contentious maturation of the regenerated axons, especially in the compound muscle action potentials. Study III showed that even at 20 mm, the M-graft-w-Dox group promoted axonal regeneration and functional regeneration., Conclusion:  The M-graft-w-Dox group showed superior regeneration results, and this easy and short-term procedure can expand the muscle graft clinical indication for the treatment of peripheral nerve defects., Competing Interests: None declared., (Thieme. All rights reserved.)

Purpose: To report a series of recurrent idiopathic macular holes treated by means of a free autologous internal limiting membrane flap and compare visual and anatomic results to a control group undergoing further internal limiting membrane peeling and novel gas tamponade., Methods: Retrospective surgical series of 15 consecutive patients receiving autologous internal limiting membrane flap compared to 14 patients operated on for internal limiting membrane peeling enlargement. Autologous internal limiting membrane flap was created after brilliant blue G staining, internal limiting membrane lifting, perfluorocarbon bubble injection and creation of a wide internal limiting membrane free flap translocated underneath perfluorocarbon liquid, to the macular hole bed. Both groups were tamponated with 20% SF6 and positioned face down for 4 h a day for 3 days., Results: Macular hole closed in 14/15 (93.3%) patients of the autologous internal limiting membrane group and 9/14 (64.2%) controls (p < 0.05). Visual acuity increased from 0.05 ± 0.03 to 0.23 ± 0.13 Snellen in the autologous internal limiting membrane group and from 0.05 ± 0.03 to 0.14 ± 0.10 Snellen of controls (p < 0.05 for both). Vision of the autologous internal limiting membrane group improved more than controls at 1 month (p = 0.043) and 3 months (p = 0.045). Inner segment/outer segment interruption at 3 months was smaller in the autologous internal limiting membrane group than controls, reducing from 1230 ± 288 µm at baseline to 611 ± 245 and 547 ± 204 µm at 3 months versus 1196 ± 362, 745 ± 222 and 705 ± 223 µm, respectively (p < 0.05)., Conclusion: Autologous internal limiting membrane flap can effectively close recurrent idiopathic macular holes with a higher closure rate, smaller residual inner segment/outer segment line interruption and higher visual acuity at 3 months than previous standard of care.

Purpose: To compare the results of vitrectomy with internal limiting membrane (ILM) peeling and inverted ILM flap for treating myopic macular hole without retinal detachment., Methods: Twenty-eight eyes of 28 patients undergoing vitrectomy with either ILM peeling (n = 16) or inverted ILM flap technique (n = 12) were included. Outcomes were myopic macular hole closure by optical coherence tomography and visual acuity at 6 months and at the end of follow-up., Results: Closure of myopic macular hole was achieved in 13 eyes (81.2%) of the ILM peeling group and in 11 eyes (91.7%) of the inverted ILM flap group. The median length of follow-up was 18 months in the peeling group and 10.3 in the inverted group. There were not statistically significant differences between restoration of the external limiting membrane, external limiting membrane and ellipsoid zone, and none of both layers between the two groups. The median best-corrected visual acuity (logarithm of minimal angle of resolution) at the end of follow-up was 0.25 (20/35 Snellen) in the peeling group and 0.4 (20/50) in the inverted group (P = 0.027)., Conclusion: Both techniques were associated with high closure rates of myopic macular hole but the small sample size and the retrospective design prevents any claims of superiority of one technique over the other.

Purpose: The purpose of the present paper is to describe a surgical technique aimed at creating multiple layers of Internal Limiting Membrane (ILM) using Perfluorocarbon Liquid (PFCL) in order to favour the closure of large, chronic and myopic Macular Holes (MH)., Methods: Thirty patients belonging to 3 subgroups: large (> 500 μm), chronic (> 12 months) and myopic (> - 9 diopters), MHs, underwent surgery and completed 6 months follow-up. The ILM was engaged and peeled 360° around the MH, hinged to the rim and folded over the hole. A PFCL bubble spanning the vascular arcades was then injected and the ILM is grasped repeatedly to fold the distal edge towards the MH centre, creating multiple ILM layers over the MH., Results: MH closed in 26/30 cases (86.6%) with no significant difference among subgroups. Vision improved 2.57 ± 1.56 Snellen lines from LogMAR 1.50 ± 1.19 to 1.19 ± 1.32 (p < 0.01). Ellipsoid Zone (EZ) interruption width reduced from 1129 ± 439 μm to 258 ± 507 μm (p < 0.001) and correlated to pattern of MH closure, post-BCVA and line improvement (p < 0.001 in all cases)., Discussion: The use PFCL allows multiple ILM layers and resulted in a high closure rate. Pattern of MH closure differs from those previously described leaving a plug of ILM tissue that interrupts retinal architecture often only in the inner layers. PFCL gravity and hydrophobicity displace aqueous while the intensely polar opposite faces of the ILM attract each other. The folded ILM plugs MH and bridges the gap and may help glial cell proliferation and migration.

Purpose: To review a series of highly myopic eyes with retinal detachment undergoing pars plana vitrectomy with autologous internal limiting membrane (ILM) flap placed over posterior retinal breaks located in areas of choroidal atrophy., Methods: Retrospective review of 13 consecutive patients receiving pars plana vitrectomy with ILM flap over causative breaks, compared with 19 controls receiving the same surgery with ILM peeling but no ILM flap. Main outcome measures included anatomical success rate, visual acuity, number of surgeries and the rate of silicone oil removal., Results: Patients in the ILM group required 2.08±0.37 interventions versus 2.58±0.75 in the control group (p=0.037). One (1/13; 7.6%) patient in the ILM group required additional unplanned surgery versus 8/19 (42.10%) in the control group (p=0.038). Final anatomical success rate defined as attached retina after silicone oil (SiO) removal was 13/13 in the I-ILM group and 14/19 (73.6%) in the control group (p=0.052). No patients (0/13) in the I-ILM group retained SiO at the end of follow-up versus 4/19 (21.1%) patients in the control group (p=0.061). Best-corrected visual acuity at the end of follow-up was logMAR 0.65±0.36 (20/91 Snellen) in the ILM group and logMAR 0.89±0.44 (20/158 Snellen) in the control group (p=0.20)., Conclusion: Autologous ILM may help seal posterior retinal breaks and improve the surgical prognosis of retinal detachment due to breaks located over areas of choroidal atrophy within the myopic staphyloma., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background/objectives: To assess the efficacy of dynamic intraoperative spectral-domain optical coherence tomography (iSD-OCT) imaging for inverted internal limiting membrane (ILM) flap technique (IILMFT) in large macular hole (MH) surgery., Subjects/methods: Prospective, non-randomized, observational study was conducted on 8 eyes of 7 patients with large, chronic and recurrent MHs, which were treated by pars plana vitrectomy (PPV) with IILMFT. All patients underwent standard pre- and postoperative examination. The iSD-OCT imaging was performed using microscope integrated systems before, during, and after ILM peeling. The iSD-OCT data were post-processed using graphic software and reviewed for tissue behavior and instruments position., Results: The real-time iSD-OCT-assisted IILMFT allowed for real-time imaging of the entire surgery with visualization of the MH, vitreoretinal instruments, and all steps of inverted ILM flap formation. In spite of shadowing created by the steel instruments, it was possible to follow and control the distance between the instrument tips and retinal layers. Dynamic imaging of the surgical maneuvers including ILM peeling and mechanical apposition of MH edges revealed the iatrogenic impact on the retina (depression and appearance of hyporeflective zones). iSD-OCT imaging could confirm the proper position of the inverted ILM flap at the very end of the surgery after fluid-air exchange., Conclusions: iSD-OCT imaging is an effective tool for learning and performing a well-controlled and safe inverted ILM flap technique in patients with large MH. Clinical significance of the structural iSD-OCT findings has to be further studied.

The conjunctiva is a clear tissue covering the white part of the eye and lines the back of the eyelids. Conjunctival diseases, such as symblepharon, cause inflammation, discharges, and photophobia. The treatment often requires excision of large parts of conjunctiva. Tissue engineering of conjunctival cells using human amniotic membrane (HAM) denuded of its epithelium as a basement membrane scaffold has been shown to be effective for covering conjunctival defects. However, most epithelial denudation protocols are time-consuming and expensive or compromise HAM's basement membrane structure and matrix components. We have previously described a method to de-epithelialize HAM using ice-cold urea (uHAM). In this report, we used this method to provide tissue-engineered constructs with cultivated conjunctival epithelial cells on uHAM in two patients, one with a giant conjunctival nevus and the other with a large symblepharon. Autologous conjunctival epithelial cells harvested from incisional biopsies of these two patients were cultured on the uHAM scaffold. The transplantation of tissue-engineered constructs to patients' ocular surface immediately after the removal of lesions showed successful reconstruction of the ocular surface. Postoperatively, there were neither recurrence of lesions nor epithelial defects throughout the follow-up (up to 7 and 19 months, respectively). This report highlights the translational potential of an efficient and inexpensive method to prepare de-epithelialized HAM as a basement membrane scaffold for cell-based tissue-engineered treatments of ocular surface disorders. Stem Cells Translational Medicine 2019;8:620&626., (© 2019 The Authors. STEM CELLS TRANSLATIONAL MEDICINE published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.)

Purpose: To evaluate long-term change in functional and structural outcomes after successful repair of large macular holes (MH) with internal limiting membrane (ILM) flap techniques., Methods: Eleven consecutive patients were reviewed over a 1-year time period after the successful repair of large MH with ILM flap techniques. SD-optical coherence tomography (SD-OCT) images were taken to assess the anatomical outcome after surgery, while the best-corrected visual acuity (BCVA) was tested using Snellen charts to evaluate the functional outcome. Each patient was evaluated at 1, 6 and 12 months after surgery, respectively., Results: All cases achieved complete anatomical closure. All patients showed a microstructural regeneration of the retina with a decrease in ellipsoid zone defects over the 1-year follow-up. Functionally, as compared to baseline, all of the patients showed improvements in best-corrected visual acuity of 1-4 lines at the final examination after 12 months post-operatively., Conclusions: Long-term results show further improvement in the best-corrected visual acuity as well as further microstructural regeneration of the retina and decrease in ellipsoid zone defects over time. The exact mechanism, which promotes closure of the macular hole and reconstruction of the ellipsoid zone after internal Limiting Membrane autograft surgery, still remains unknown.

Internal limiting membrane (ILM) grafting provides a useful option for repair of large and refractory macular holes that fail to close following prior ILM removal. However, current ILM graft techniques are associated with several challenges that may result in failure, most notably the difficulty in maintaining the graft in situ. In this video, the authors describe their modified technique for ILM grafting using a double layer of viscoelastic for stabilization in situ during the procedure. Four of five eyes managed with this technique demonstrated type 1 closure, and all eyes demonstrated improvement in visual acuity., (Copyright 2019, SLACK Incorporated.)

Purpose: Editorial to De Giacinto et al case report on free autologous neurosensory retina patch., Methods: Literature review and experts' opinion RESULTS: In the present issue, De Giacinto et al describe a free autologous neurosensory retina patch to close a chronic macular hole. This new technique was made necessary by an extended internal limiting membrane peeling during the first surgery, that prevented grafting a patch of internal limiting membrane when the hole did not close. We hereby review pros and cons of patching a chronic macular hole with an internal limiting membrane patch, as well as the importance of not over-enlarging a peeling., Discussion: Internal limiting membrane patch can be considered in chronic macular holes. It may not be an option in cases of over-enlargement of a previous peel; free autologous neurosensory retina patch may be a valid alternative in such cases.

Purpose: Internal limiting membrane (ILM) flap transposition in surgical repair of macular holes represents a new technique offering good anatomical success rates with large macular holes. The aim of the study was to examine microperimetric outcomes 1 year after ILM flap transposition for surgical repair of macular holes., Methods: Patients with idi-opathic macular holes scheduled for 23-G pars plana vitrectomy with ILM peeling, ILM flap transposition, and SF6 tamponade were examined in a prospective case series. Distance corrected visual acuity (DCVA), optical coherence tomography, and microperimetry were measured before and 1 year after surgery., Results: In all eyes, closure of the macular hole could be achieved. While foveal sensitivity improved in 71%, perifoveal sensitivity improved in 86% of the cases. DCVA improved in 83% and was unchanged in 17% of the cases., Conclusions: Beside visual acuity, foveal and perifoveal macular sensitivity improved, underlining the functional success of surgery after ILM peeling with ILM flap transposition., (© 2018 S. Karger AG, Basel.)

Background and Objective: To evaluate long-term outcomes of inverted internal limiting membrane (ILM) stuffing into the optic disc pit for optic disc pit maculopathy (ODP-M) compared with vitrectomy with ILM peeling alone., Patients and Methods: Twelve eyes of 12 patients who underwent vitrectomy for ODP-M and followed up more than 12 months were included. We retrospectively analyzed outcomes of inverted ILM flap stuffing into ODP (group 1, n = 6) with ILM peeling alone (group 2, n = 6)., Results: At 12 months, both groups showed significant improvement in best-corrected visual acuity and central macular thickness. On comparison, significantly faster resolution of maculoschisis was found in group 1 compared with group 2 (P = .012)., Conclusions: Pars plana vitrectomy (PPV) with ILM peeling and PPV with inverted ILM stuffing are effective treatment modalities for ODP-M, with inverted ILM stuffing showing faster resolution of maculoschisis. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:e226-e232.]., (Copyright 2018, SLACK Incorporated.)

Purpose: Recent studies described that in approximately 14% to 16% of cases of macular holes treated with the inverted internal limiting membrane flap technique, the hole was closed only by a thin layer of inverted internal limiting membrane-"flap closure." The aim of this article was to describe the functional and anatomical results in flap closure macular holes and also the mechanism of flap closure., Methods: A retrospective observational study of 149 eyes of 139 patients treated with vitrectomy using the inverted internal limiting membrane flap technique was reviewed to aggregate eyes with flap closure. Complete ophthalmic examination was performed preoperatively and at 7 days, 1, 3, 6, and 12 months after surgery., Results: Flap closure (Group 1) was noted in 24 eyes and other closure types in 125 eyes (Group 2). The mean minimal and base diameters of the macular holes in the flap closure group were greater than those in Group 2 (P < 0.001). The mean postoperative best-corrected visual acuity in the flap closure group (20/100) was lower than that in Group 2 (20/50) (P < 0.001)., Conclusion: Flap closure probably enables closure of large macular holes with a higher probability of remaining open without the use of the inverted internal limiting membrane flap technique. Foveal architecture continuously improved.

Purpose: The purpose of this study is to investigate the effectiveness of a new surgical technique of non-inverted pedicle internal limiting membrane (ILM) transposition for the treatment of eyes with large macular hole., Methods: This is a retrospective, consecutive, interventional case series. Twelve eyes of 12 consecutive patients who underwent vitrectomy for the treatment of a large macular hole (MH size > 400 µm) were treated. ILM was peeled and left with a pedicle attached to the superior temporal retina. The macular hole was covered by transposition of the pedicle ILM in a non-inverted way. Preoperative and postoperative best-corrected visual acuity (BCVA), SD-OCT image, macular sensitivity by microperimetry, and multifocal electroretinogram (mERG) response were evaluated. All of the patients were followed for more than 3 months., Results: Postoperative OCT examination confirmed 11 of 12 macular hole closed (91.7%). Six macular hole filled with silicone oil closed as early as the next day. The postoperative BCVA significantly increased compared with preoperative BCVA (P = 0.002). The improvement of macular sensitivity within 2° and 8° circle was also statistical significant (P = 0.018 and P = 0.017, respectively). Fixation stability, shown as the percentage of fixation point within the 2° circle and 4° circle, was remarkably improved (P = 0.017 and P = 0.018, respectively). The R1/R2 and R1/R4 ring ratios also increased significantly as compared with that of baseline., Conclusion: These findings indicate that the non-inverted pedicle ILM transposition results in a high incidence of anatomic closure with good visual outcome for the treatment of large macular hole.

Background and Objective: To determine the efficacy of a new surgical technique involving use of a contralateral autologous internal limiting membrane (ILM) free flap for closure of a refractory macular hole (MH)., Patients and Methods: Closure could not be achieved after several MH surgeries in a 72-year-old woman with an epiretinal membrane (ERM) in the right eye and a chronic MH in the left eye. Therefore, the authors performed surgery on the left eye using a contralateral autologous ILM free flap obtained during ERM surgery performed on the right eye., Results: The refractory MH had disappeared, and the patient's corrected visual acuity was improved in both eyes by 4 months after surgery., Conclusion: When a suitable free flap cannot be obtained from the operated eye, contralateral autologous ILM transplantation has the potential to improve functional and anatomical outcomes in an eye with a refractory MH. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:e75-e77.]., (Copyright 2018, SLACK Incorporated.)

Background: The inverted flap (IF) technique has recently been introduced in macular hole (MH) surgery. The IF technique has shown an increase of the success rate in the case of large MHs and in MHs associated with high myopia. This study reports the anatomical and functional results in a large series of patients affected by MH treated using pars plana vitrectomy and gas tamponade combined with internal limiting membrane (ILM) peeling or IF., Methods: This is a retrospective, consecutive, nonrandomized comparative study of patients affected by idiopathic or myopic MH treated using small-gauge pars plana vitrectomy (25- or 23-gauge) between January 2011 and May 2016. The patients were divided into two groups according to the ILM removal technique (complete removal vs. IF). A subgroup analysis was performed according to the MH diameter (MH < 400 µm and MH ≥ 400 µm), axial length (AL < 26 mm and AL ≥ 26 mm), and the presence of chorioretinal atrophy in the macular area (present or absent)., Results: We included 620 eyes of 570 patients affected by an MH, 300 patients underwent pars plana vitrectomy and ILM peeling and 320 patients underwent pars plana vitrectomy and IF. Overall, 84.94% of the patients had complete anatomical success characterized by MH closure after the operation. In particular, among the patients who underwent only ILM peeling the closure rate was 78.75%; among the patients who underwent the IF technique, it was 91.93% (P = 0.001); and among the patients affected by full-thickness MH ≥400 µm, success was achieved in 95.6% of the cases in the IF group and in 78.6% in the ILM peeling group (P = 0.001); among the patients with an axial length ≥26 mm, success was achieved in 88.4% of the cases in the IF group and in 38.9% in the ILM peeling group (P = 0.001). Average preoperative best-corrected visual acuity was 0.77 (SD = 0.32) logarithm of the minimum angle of resolution (20/118 Snellen) in the peeling group and 0.74 (SD = 0.33) logarithm of the minimum angle of resolution (20/110 Snellen) in the IF group (P = 0.31). Mean postoperative best-corrected visual acuity was 0.52 (SD = 0.42) logarithm of the minimum angle of resolution (20/66 Snellen) in the peeling group and 0.43 (SD = 0.31) logarithm of the minimum angle of resolution (20/53 Snellen) in the IF group (P = 0.003)., Conclusion: Vitrectomy associated with the inverted ILM flap technique seems to be effective surgery for idiopathic and myopic large MHs, improving both functional and anatomical outcomes.

To report a case of a serous macular detachment associated with optic pit that did not improve after a previous vitrectomy with internal limiting membrane (ILM) peeling, peripapillary laser, and gas tamponade. The authors performed a lens-sparing 27-gauge pars plana vitrectomy with autologous transplantation of ILM inside the optic nerve pit and gas tamponade. The subretinal fluid gradually resolved and visual acuity improved to 20/20 at the tenth month after surgery. The authors did not observe a recurrence of subretinal fluid during the 14 months of follow-up. Autologous transplantation of the ILM may be effective to repair recurring optic disc pit maculopathy. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:712-714.]., (Copyright 2018, SLACK Incorporated.)

Purpose: We investigated the surgical results of macular hole retinal detachment (MHRD) with a modified C-shaped temporal inverted internal limiting membrane (ILM) flap to reconstruct the foveolar architecture in highly myopic eyes., Methods: Eighteen highly myopic eyes with MHRD in 17 patients who underwent a vitrectomy with a modified C-shaped temporal inverted ILM flap were followed for 12 months. Anatomic outcomes were evaluated by fundus examinations and optical coherence tomography. The preoperative and postoperative best-corrected visual acuities (BCVAs) were compared as functional outcomes., Results: Women accounted for 88% of the MHRD patients. The mean age was 60.2 ± 8.2 years. The mean axial length was 29.25 ± 2.10 mm. Type 1 and type 2 MHRD was present in four eyes and 14 eyes, respectively. After a single surgery, the hole was closed in 18 eyes (100%). Retinal attachment was achieved in 95%. Persistent shallow subretinal fluid (SRF) was noted in one case, which was resolved at follow-up. The surgery significantly improved BCVAs (from 1.7 ± 0.6 to 0.72 ± 0.4 logarithm of the minimum angle of resolution units [p < 0.001]) at the last visit. In total, 94.4% of the eyes had restored foveolar architecture. Ellipsoid zone recovery within the foveola was found in 77.8% of the eyes., Conclusion: A vitrectomy and modified C-shaped inverted temporal ILM flap is effective for closing MHs, reattaching the retina, restoring the foveolar architecture and significantly improving the postoperative BCVA in MHRD patients. This technique is feasible, and we propose 'presumed' Müller cell cone repair in MHRD surgery., (© 2017 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.)

This case report aims to study active cone regeneration and its functional correlation in optic disc pit maculopathy (ODPM) with a large outer macular defect treated with autologous internal limiting membrane (ILM) "chunk" transplantation. Outcome analysis was done using spectral-domain optical coherence tomography (SD-OCT), adaptive optics, and microperimetry. Visual acuity improved from counting fingers at 2 meters to 6/18 Snellen equivalent postoperatively, whereas SD-OCT demonstrated closure of outer subfoveal defect. Adaptive optics imaging revealed maximum active cone concentration of 14,232/mm 2 at the fovea, and fixation stability improved to 61% and 90% (P1 and P2, respectively) on microperimetry. To conclude, autologous ILM "chunk" transplantation provides an additional therapeutic option in treatment of ODPM with large outer macular defect. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:152-155.]., (Copyright 2018, SLACK Incorporated.)

Purpose: To determine whether surgical manipulation steps of the internal limiting membrane (ILM) flap, such as ILM trimmed, ILM tuck inside the hole, ILM massage, are mandatory to obtain satisfactory outcomes for the repair of large stage IV idiopathic macular hole using the inverted ILM flap technique., Methods: In this interventional comparative prospective single-masked study, 81 eyes were randomized into 2 treatments groups. In Group 1 (41 eyes), the classic inverted ILM flap technique was performed. In Group 2 (40 eyes), a modified procedure was used: after ILM peeling, no extra flap manipulation was performed. The macular hole was covered by the inverted ILM flap because of the air pressure at the time of the fluid-air exchange., Results: At 12 months, macular hole closure was observed in 40 eyes (97.6%) in Group 1 and in 39 eyes in Group 2 (97.5%). U-shape closure rate, ellipsoid zone defects, and external limiting membrane defects were similar in both groups. The results indicate no statistical difference in anatomical and functional success between both groups., Conclusion: The macular hole closure rate, improved visual acuity, and no extra complications indicate noninferiority of the modified inverted ILM technique. Internal limiting membrane finishing, tucking, and massage may not be required to obtain surgical success.

Purpose: To compare the results of vitrectomy with complete internal limiting membrane (ILM) removal and inverted ILM flap in the treatment of myopic macular hole (MMH)., Methods: Seventy eyes of 68 patients with MMH undergone pars-plana vitrectomy (PPV) with either complete ILM removal (n = 36, Group 1) or inverted ILM flap technique (n = 34, Group 2) were included in the study. Outcomes measured were the rate of MMH closure assessed by optical coherence tomography (OCT) and visual acuity (BCVA) at six months., Results: Closure of MMH was achieved in 22 cases of Group 1 (61%) and in 32 cases of Group 2 (94%). Surgical failure was reported in 14 cases of Group 1 (39%) and in one case of Group 2 (3%). Average best-corrected visual acuity (BCVA) changed from 0.60 to 0.58 in Group 1 (P = 0.329) and from 0.70 to 0.39 in Group 2 (P < 0.01). Logistic regression analysis showed that inverted ILM flap technique was associated with 22 times higher probability of anatomic success, regardless of the MMH diameter., Conclusion: Inverted ILM flap should be preferred to complete ILM removal for the treatment of MMH. The outcomes reported with this technique were better than any other technique described until now.

The authors describe a modified perfluoro-n-octane (PFO)-assisted autologous internal limiting membrane (ILM) transplantation technique for macular hole (MH) reintervention and present results from a series of 11 patients. The authors harvested a free ILM flap and transplanted it into the MH under a PFO bubble. The time at which PFO is injected, the extent of coverage of PFO, and the sequence of fluid-air exchange (FAE) are crucial to overcome previously described technical difficulties of relieving the flap from forceps, stabilizing the flap into the MH, and prevention of flap dislodgement during FAE. A successful U-shaped closure was observed in 10 of 11 cases (90.9%). One case (9.1%) showed flat open closure. The postoperative visual gain was statistically significant (P = .01). [Ophthalmic Surg Lasers Imaging Retina. 2017;48:416-420.]., (Copyright 2017, SLACK Incorporated.)

Background: To present the surgical technique and clinical outcomes of transplantation of autologous internal limiting membrane (ILM) for large macular holes (MHs) after failed surgeries with ILM removal., Methods: Thirteen eyes of 13 consecutive patients with MHs larger than 500 μm after failed surgeries with ILM removal underwent vitrectomy with transplantation of autologous ILM. In the ILM transplantation technique, a small piece of the ILM was peeled off and transplanted inside the macular hole. Fluid-air exchange was then performed. The air was then replaced with 10 % perfluoropropane (C 3 F 8 ) gas. Comprehensive ophthalmologic examinations and spectral-domain optical coherence tomography were performed preoperatively and postoperatively. The main outcome measures were best-corrected Snellen visual acuity (BCVA) and MH closure rate., Results: The preoperative mean base diameter of the MHs was 1637.6 + 412.7 μm (range, 814-2092 μm). The preoperative mean minimum diameter was 814.4 + 255.0 μm (range, 546 μm-1485 μm). Complete MH sealing was achieved in 12 eyes after transplantation of the ILM flap. The mean BCVA was 1.15 + 0.21 (range, 1.0-1.6) before surgery and 0.99 + 0.17 (range, 0.7-1.3) at 12 months postoperatively. There was a significant difference in BCVA before versus after the surgery (t = 3.825, P = 0.0002, paired t- test)., Conclusions: Transplantation of autologous ILM is an effective addition to the surgical options for large macular holes after failed surgeries with ILM removal.

Purpose: To investigate the surgical outcomes of inverted internal limiting membrane (ILM) insertion in macular hole (MH)-associated retinal detachment (RD) in high myopia., Design: Retrospective, interventional, consecutive case series., Methods: This study was conducted at 2 medical centers. Consecutive cases of highly myopic eyes with MH-associated RD were included. Forty eyes were divided into 2 groups: Group 1 (20 eyes) received vitrectomy, ILM peeling within the arcade area, and air-fluid exchange, and Group 2 (20 eyes) received vitrectomy, inverted ILM inserted into the macular hole, and air-fluid exchange. Optical coherence tomography was used to observe the closure of the macular hole. Corrected visual acuity (VA) was also recorded. Two-sample t test and Mann-Whitney U test were used for statistical analysis to compare differences between the 2 groups., Results: MH was closed in 35% of the eyes in Group 1 and in all eyes in Group 2 (P < .001). Significant improvement in VA in logarithm of minimal angle of resolution (logMAR) was achieved in both groups. There was no difference in the initial, final, or improvement of logMAR VA in the 2 groups., Conclusion: Inverted ILM insertion into a macular hole effectively helps close the macular hole in MH-associated RD in high myopia. This may prevent the possible re-detachment from the MH. A prospective study with a larger number of cases and longer follow-up may help validate our findings., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background and Objective: To determine the efficacy of the pedicle internal limiting membrane (ILM) transposition flap technique for refractory macular holes (MHs) in which the inverted ILM flap technique cannot be performed., Patients and Methods: The pedicle ILM flap transposition technique was conducted by transconjunctival microincision vitrectomy. The authors attempted to peel the remaining ILM inferior from the MH to create an ILM flap. This ILM was still attached to the retina at the upper part of the MH and covered the MH. Finally, fluid-gas exchange was performed. After surgery, patients remained face-down for 1 week. This procedure was performed in two eyes., Results: There were no adverse events, and MHs were closed successfully in both study eyes., Conclusion: The pedicle ILM flap transposition technique has the potential to improve functional and anatomical outcomes in patients with refractory MHs., (Copyright 2015, SLACK Incorporated.)

Objective: To evaluate a technique of autologous internal limiting membrane (ILM) fragment transplantation for the treatment of large, chronic, and/or refractory macular holes (MH)., Design: This was a 6-month prospective interventional case series., Method: Ten eyes of 10 patients with MH underwent pars plana vitretomy (PPV) and ILM peeling followed by transplantation of an autologous ILM fragment to the MH. Six patients had primary MH with an internal diameter greater than 500 µm and a duration of more than 18 months, including 1 patient with nonproliferative diabetic retinopathy previously treated with panretinal photocoagulation. Four eyes with MH had previously been submitted to PPV (i.e. 1 for retinal detachment and 3 to attempt to close large MH). One of the latter also displayed juxtapapillary choroidal neovascularization due to age-related macular degeneration. The primary and secondary outcomes were MH closure and improvement of the best corrected visual acuity (BCVA), respectively., Results: Complete MH closure was achieved in all cases. A statistically significant improvement in the average BCVA was observed after 6 months of follow-up (p = 0.018; paired t test). The BCVA improved in 8 eyes (80%), and in 6 of those eyes it improved by ≥ 15 letters. In 1 patient, the BCVA remained unchanged after the surgery, but the visual field reportedly improved. One patient experienced a slight worsening (0.16 logMAR). Two cases developed atrophy of the retinal pigment epithelium despite MH closure and BCVA improvement., Conclusion: Treatment with autologous ILM fragment transplantation seems to be an efficient alternative for large, chronic, and refractory MH., (© 2015 S. Karger AG, Basel.)

The basement membranes (BMs) of the nervous system include (a) the pial BM that surrounds the entire CNS, (b) the BMs that outline the vascular system of the CNS and PNS and (c) the BMs that are associated with Schwann cells. We previously found that isolated BMs are bi-functionally organized, whereby the two surfaces have different compositional, biomechanical and cell adhesion properties. To find out whether the bi-functional nature of BMs has an instructive function in organizing the tissue architecture of the developing nervous system, segments of human BMs were inserted into (a) the parasomitic mesoderm of chick embryos, intersecting with the pathways of axons and neural crest cells, or (b) into the midline of the embryonic chick spinal cord. The implanted BMs integrated into the embryonic tissues within 24h and were impenetrable to growing axons and migrating neural crests cells. Host axons and neural crest cells contacted the epithelial side but avoided the stromal side of the implanted BM. When the BMs were inserted into the spinal cord, neurons, glia cells and axons assembled at the epithelial side of the implanted BMs, while a connective tissue layer formed at the stromal side, resembling the tissue architecture of the spinal cord at the pial surface. Since the spinal cord is a-vascular at the time of BM implantation, we propose that the bi-functional nature of BMs has the function of segregating epithelial and connective cells into two adjacent compartments and participates in establishing the tissue architecture at the pial surface of the CNS., (Copyright © 2014 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.)

Purpose: To determine the effectiveness of autologous transplantation of the internal limiting membrane (ILM) for refractory macular holes., Design: Prospective, interventional case series., Patient and Methods: Ten eyes of 10 consecutive patients who underwent autologous transplantation of the ILM for the treatment of refractory macular holes were studied. The primary diseases in these patients were large idiopathic macular holes that had existed for more than 1 year (4 eyes), a traumatic macular hole (1 eye), myopic foveoschisis (2 eyes), foveoschisis resulting from pit-macular syndrome (2 eyes), and proliferative diabetic retinopathy (1 eye). Apart from the 5 eyes with idiopathic or traumatic macular holes, macular holes developed in the other 5 eyes after initial vitrectomies with ILM removal. In all eyes, regular macular hole surgery failed to achieve closure. The main outcome measures used in this study were macular hole closure and best-corrected visual acuity (BCVA)., Results: Macular holes were closed successfully in 9 eyes (90%) after autologous transplantation of the ILM. The postoperative BCVAs were significantly better than the preoperative BCVAs (P = .007, paired t test). Postoperative BCVAs improved by more than 0.2 logarithm of the minimal angle of resolution units in 8 eyes (80%) and were unchanged in 2 eyes (20%)., Conclusions: Although this is a pilot study, the results suggest that autologous transplantation of the ILM may contribute to improved anatomic and visual outcomes in the treatment of refractory macular holes and may warrant further investigation., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Background: Pleurodesis is used in the treatment of spontaneous pneumothorax or refractory pleural effusions of different etiologies. Several agents have been employed, but many questions remain unanswered about their effectiveness and toxicity. Use of autologous blood pleurodesis in clinical practice has been described in the literature without any clear consensus regarding its efficacy. Experimental studies using this technique are limited to a single study in rabbits. We performed a prospective, randomized, observer-blinded, controlled study to evaluate the safety and efficacy of increasing doses of autologous blood pleurodesis in a novel rat model., Materials and Methods: Twenty-eight albino Wistar rats were divided into four groups. Groups 1, 2, and 3 were the study groups and group 4 was the control group, with seven animals in each group. Groups 1, 2, and 3 were given autologous blood, 1 mL/kg, 2 mL/kg, 3 mL/kg, respectively, and group 4 (control) was given only 2 mL/kg saline intrapleurally. The rats were sacrificed on postoperative day 30. The surfaces were graded by macroscopic (visible adhesion formation) and microscopic (inflammation and fibrosis) examination., Results: Macroscopically, group 2 and group 3 developed significantly more adhesions; 3 mL/kg autologous blood produced the most significant pleurodesis with generalized adhesions seen between visceral, parietal, and mediastinal pleura. Microscopic examination showed that all study groups developed an inflammatory response at the site of blood injection. There were no pathologic changes in ipsilateral and contralateral lung parenchyma., Conclusions: Autologous blood at doses 2-3 mL/kg were shown to be effective to produce adhesions in 30 d, and the results were highly reproducible in all rats. We propose that the occasional negative results obtained in humans may be related to an insufficient amount of injected blood, as observed in our rat model., (Copyright 2010 Elsevier Inc. All rights reserved.)

The purpose of the present study is to test whether chemically extracted acellular nerve segments can be used to repair the sciatic nerve gap. Fifteen canines were divided into acellular nerve allografting group (ANG, six canines), autografting group (AG, six canines), and fresh nerve allografting group (FNG, three canines). The sciatic nerves on the right side of the animals were exposed, and 5-cm-long segments of the nerves were removed from the midthigh level and replaced by the three types of grafts. At 6 months after grafting, all animals in the ANG and AG had similar patterns of right posterior limb gait cycle and right ankle movements. Moreover, the animals in the ANG and AG had similar nerve regeneration, with dense regeneration fibers in the distal tibial nerves and obvious motor end plates in the target muscle. But in FNG, the area surrounding the graft was scarred as the result of inflammation, and there was a brown central area where there was little nerve regeneration. All of the above shows that chemical acellular nerve allografting can be used to repair a gap as long as 5 cm in the continuity of the sciatic nerve in canines and has similar effects to autografting.

Background: A nerve gap must be bridged by autologous nerve grafts that serve as scaffold and consist of viable Schwann cells that promote regeneration. Owing to the necessary immunosuppression, nerve allografts remain limited to special cases. Alternatively, tissue engineering of peripheral nerves focuses on the implantation of cultured Schwann cells into suitable scaffolds. We established grafts from Schwann cells and basal lamina from acellular muscles. These grafts offer a regeneration that is comparable to autologous nerve grafts., Methods: Using a rat model (DALEW.1W strain), the present study evaluates the host response to acellular muscle allografts by assessing cellular reaction major histocompatability (MHC) class I and II, lymphocytes, macrophages. The results were compared to untreated muscle allografts., Results: Macroscopically, the untreated muscles showed a strong inflammatory reaction as a sign of rejection, whereas the acellular muscle offered only minor reactions in the periphery of the graft. Expression of MHC I and II and invasion of CD4/CD8 positive cells and macrophages was pronounced after grafting the untreated muscles. Only a moderate reaction was noted for these parameters after acellular grafting., Conclusions: The acellular muscle graft is not completely free of cellular response; however the reaction is considered to be moderate and is located only in the periphery. To date, synthetic scaffolds that represent endoneurial tube-like structures and allow sufficient adhesion of Schwann cells and axonal regeneration are not available. The decreased response to acellular muscle allografts offers at least a basis for further experiments.

Objective: To explore the possibility to bridge peripheral nerve defects by xenogeneic acellular nerve basal lamina scaffolds., Methods: Thirty SD rats were randomly divided into 5 groups; in each group, the left sciatic nerves were bridged respectively by predegenerated or fresh xenogeneic acellular nerve basal lamina scaffolds, autogenous nerve grafting, fresh xenogeneic nerve grafting or without bridging. Two kinds of acellular nerve basal lamina scaffolds, extracted by 3% Triton X-100 and 4% deoxycholate sodium from either fresh rabbit tibial nerves or predegenerated ones for 2 weeks, were transplanted to bridge 15 mm rat sciatic nerve gaps. Six months after the grafting, the recovery of function was evaluated by gait analysis, pinch test, morphological and morphometric analysis., Results: The sciatic nerve function indexes (SFI) were -30.7% +/- 6.8% in rats treated with xenogeneic acellular nerve, -36.2% +/- 9.7% with xenogeneic predegenerated acellular nerve, and -33.9% +/- 11.3% with autograft respectively (P > 0.05). The number of regenerative myelinated axons, diameter of myelinated fibers and thickness of myelin sheath in acellular xenograft were satisfactory when compared with that in autograft. Regenerated microfascicles distributed in the center of degenerated and acellular nerve group. The regenerated nerve fibers had normal morphological and structural characters under transmission electron microscope. The number and diameter of myelinated fibers in degenerated accellular nerve group was similar to that of autograft group (P > 0.05). Whereas the thickness of myelin sheath in degenerated accellular nerve group was significantly less than that of autograft group (P < 0.05)., Conclusion: The above results indicate that xenogeneic acellular nerve basal lamina scaffolds extracted by chemical procedure can be successfully used to repair nerve defects without any immunosuppressants.

Background: The primary aim of this randomized, controlled, blinded clinical investigation was to determine if orientation of an acellular dermal matrix (ADM) allograft, basement membrane side against the tooth or connective tissue side against the tooth, affected the percent root coverage. Additional aims were to: 1) compare results of this study with results obtained from other root coverage studies; 2) determine if multiple additional sites could be successfully covered with the same surgery; 3) determine the effect of the procedure on keratinized tissue; and 4) evaluate the amount of creeping attachment obtained., Methods: Ten patients with 2 Miller Class I or II buccal recession defects > or =3 mm were treated with a coronally positioned flap plus ADM and followed for 12 months. Test sites received ADM with the basement membrane side against the root (AB), while the control sites received the connective tissue side against the root (AC). Multiple additional recession sites were treated with the same flap procedure., Results: Mean baseline recession for the AB sites was 4.2 mm and for the AC sites, 3.7 mm. Mean root coverage of 95% was obtained for both AB and AC sites. Sixty-eight additional Class I or II AB and AC sites obtained about 93% root coverage. The mean increase in keratinized tissue for both treatments was 0.80 mm. No additional root coverage was gained due to creeping attachment between 2 and 12 months., Conclusions: Treatment with ADM was an effective and predictable procedure for root coverage. The orientation of the material did not affect the treatment outcome for any of the parameters tested.

Grafting with autogenous tissue or freeze-dried skin is the generally accepted method for increasing and/or restoring the width of attached gingiva. This article describes the periodontal use of an acellular dermal allograft previously available for treating burn patients. When used as a gingival graft, this new dermal allograft has major potential advantages over the previously available periodontal graft materials, including improved color and contour match, elimination of multiple surgeries, and unlimited availability. The technique and results of acellular dermal grafting are presented and discussed. The learning objective of this article is to describe the principles and the clinical procedure of this technique. Several cases are used to illustrate this technique.

A multicenter clinical study assessed the ability of an acellular allograft dermal matrix to function as a permanent dermal transplant in full-thickness and deep partial-thickness burns. The study consisted of a pilot phase (24 patients) to identify the optimum protocol and a study phase (43 patients) to evaluate graft performance. Each patient had both a test and a mirror-image or contiguous control site. At the test site, the dermal matrix was grafted to the excised wound base and a split-thickness autograft was simultaneously applied over it. The control site was grafted with a split-thickness autograft alone. Fourteen-day take rates of the dermal matrix were statistically equivalent to the control autografts. Histology of the dermal matrix showed fibroblast infiltration, neovascularization, and neoepithelialization without evidence of rejection. Wound assessment over time showed that thin split-thickness autografts plus allograft dermal matrix were equivalent to thicker split-thickness autografts.

Acellular basal lamina grafts have been shown to be less immunogenic in comparison to cellular grafts, but possess a limited potential for supporting axonal regeneration through them. The present study describes the effect of cultured Schwann cells on enhancing regeneration through acellular grafts. 2 cm long acellular grafts, and in vitro Schwann cell populated acellular grafts were used to repair a surgically created gap in the host peroneal nerve. The transplants were analyzed at 1, 2, 4 and 8 weeks to determine their ability to support axonal regeneration. Host axonal regeneration through Schwann cell cocultured acellular grafts occurred rapidly and was significantly better as compared to non-cultured acellular grafts. The results demonstrate a beneficial effect of Schwann cell culture pretreatment on regeneration through acellular grafts and an improved recovery of the target muscle. The procedure of first preparing acellular grafts with subsequent coculture with Schwann cells offers a novel approach for the repair of injured nervous tissue.

Acellular basal lamina allografts are known to exhibit reduced immunogenicity, but the extent of host axonal regeneration through such grafts is reduced in comparison to the cellular isografts. The present study was designed to determine both the ability of cultured Schwann cells to populate acellular allografts, and the effects of Schwann cells on immunogenicity and regenerative potential. Isogeneic and allogeneic Schwann cell-populated acellular allografts of 2.0 cm length were used to repair a surgically created gap in the host rat peroneal nerve. Transplanted nerves were analyzed at 1, 2, 4, and 8 weeks later to determine their fate and ability to support axonal regeneration. Acellular allografts cocultured with isogeneic Schwann cells survived and supported axonal regeneration through them. In contrast, acellular allografts cocultured with allogeneic Schwann cells underwent rejection and were unsuccessful. The results show that cultured Schwann cells continue to exhibit immunogenicity and are a critical factor in allograft survival. It is thus important to use host-matched (isogeneic or autologous) Schwann cells to populate acellular basal lamina grafts in order to enhance their axonal growth-supporting function.

The influence on nerve regeneration of the extracellular matrix glycoprotein laminin was studied after sciatic nerve transection in 90 outbred Sprague-Dawley rats. Nerve regeneration through basal lamina grafts was comparable with regeneration through traditional nerve grafts across gaps up to 2.0 cm in length. True axonal regeneration rather than axonal branching was demonstrated by retrograde horseradish peroxidase labeling of nerve cables. Pretreatment of basal lamina grafts with antilaminin antibodies reduced the total number of regenerated axons by 90 percent with a significant decrease of nerve conduction velocity and a significant impairment of walking track patterns. The basement membrane glycoprotein laminin serves a critical role in the regeneration of peripheral nerves through basal lamina grafts.

Evacuated muscle is a possible substitute for nerve autografts in the repair of damaged peripheral nerves. Previous experiments have shown that killed or evacuated muscle grafts are as effective as nerve autografts for bridging gaps of up to 4 cm between proximal and distal nerve stumps. Evacuated muscle grafts are made of extracellular matrix components, which are good substrates for axon growth in vitro. However, experiments in vivo have generally demonstrated that live Schwann cells are essential for successful axon regeneration. In the present experiments we have used immunohistochemical techniques with anti-S100 and anti-neurofilament antibodies to visualize axon growth and Schwann cell migration into muscle grafts over the first 10 days following grafting. We only saw axons growing into grafts accompanied by Schwann cells, and most though not all Schwann cells were associated with axons. Schwann cell migration from the proximal stump in association with axons was much faster and more extensive than from the distal stump. We examined muscle grafts over the first 20 days after grafting by electron microscopy. Regenerating axons were always associated with Schwann cells, which were mostly in the basal lamina-lined tubes left by the evacuated myofibrils. A comparison between evacuated muscle grafts and grafts in which the muscle had been killed but not evacuated revealed that 7 days after grafting there were more than twice as many regenerated axons in and distal to the evacuated grafts, but that by 20 days the numbers of axons were similar in the two groups.

Autografts of peripheral nerve or allografts of muscle basal lamina were inserted into the putamen-caudate complex of rats, with the outer end of the implant being sutured to the temporalis muscle. Elongation of central axons within the grafts, as revealed by the horseradish peroxidase retrograde labelling technique, did occur in the presence of basal lamina implants. With both types of grafting materials stained neurones exhibited a comparable distribution, being mainly found in the proximity of the central tip of the grafts. However, labelled cells in the presence of basal lamina were limited in number, compared with peripheral nerve autografts. Therefore, the usefulness of implants of muscle basal lamina into the central nervous system, in order to direct regenerating central axons toward distant target regions, is limited. This material might be suitable, as an alternative grafting material, in experimental models where avoidance of neurological impairment or size and length of the graft are crucial factors.

The suitability of muscle basement membrane tubes as alternative to autogenous nerve grafting was appraised by comparing the nerve regeneration process in muscle basement membrane tube grafts used to bridge gaps in peripheral nerves with that in nerve grafts. The results revealed that nerve fibres grew through the muscle basement membrane tubes spanning a 2 cm gap and reinnervated end organ, at 20 weeks after operation, the nerve function recovered satisfactorily. However, the toe-spreading function, MCV and the amplitude of MAP on the muscle basement membrane tube grafting sides were not as good as on the nerve grafting sides, the axon diameter and degree of remyelination for the former also inferior to the latter. As time elapsed postoperatively, the difference between two kinds of grafts showed a tendency to diminish by all criteria used in this study. It imply that muscle basement membrane tube graft is a promising alternative to nerve grafting.

The effects of injecting human, rabbit, rat, or single-kidney homologous glomerular basement membrane (GBM) or autologous GBM, each in complete Freund's adjuvant (CFA), into 15- to 18-month-old sheep are compared. All sheep receiving heterologous GBM and 3 of 6 sheep receiving homologous GBM had anti-GBM nephritis, but such sheep did not bind autoantibodies or have Goodpasturelike lesions in their lungs. Sheep given injections of human GBM had autoantibodies to antigenic determinants shared by fetal or adult sheep and human GBM, by lung basement membranes, and by certain nonvascular basement membranes. Sheep given homologous GBM had two populations of autoantibodies: one was neither species- nor organ-specific; the other was sheep-specific. No sheep given autologous GBM had any evidence of anti-GBM autoantibodies or nephritis. Their kidneys were indistinguishable by histologic, immunohistologic, and functional studies from CFA-treated controls. Thus, sheep seem very tolerant to autologous GBM. These findings suggest that human anti-GBM nephritis may occur if the GBM is altered so that it becomes cross-reacting and induces autoantibodies, as does homologous GBM.

The suitability of muscle basal lamina as a graft material for the repair of peripheral nerves was investigated. Grafts were prepared by evacuating the myoplasm from muscles excised from rats and rabbits. This produced a material consisting mainly of basal lamina and connective tissue, with the basal lamina arranged as parallel tubes. Rat- and rabbit-derived graft material in 0.5-cm lengths was sutured into rat sciatic nerves, and 4-cm lengths of rabbit-derived graft material were interposed into rabbit sciatic nerves. For controls, 0.5-cm nerve autografts were grafted into rats and 4-cm autografts into rabbits. After 2 to 3 months, the success of the grafts was assessed functionally, electrophysiologically, and anatomically. By all these criteria the basal lamina grafts were as successful as nerve autografts; essentially the same number of axons of the same size grew through both graft types, animals recovered their limb function equally well, and the nerve conduction velocities and relative refractory periods were the same in both groups of animals. In rats, following both basal lamina and nerve autografts, the number of axons distal to the grafts was approximately the same as that proximal to them, but axon diameter and speed of conduction were significantly less than normal. The authors conclude that muscle basal lamina grafts are as effective as nerve autografts for repairing severed rat or rabbit peripheral nerves, and suggest that grafts prepared in this way may prove to be useful for nerve repair in humans.