Minimally Invasive Glaucoma Surgery: Latest Developments and Future Challenges

The development of minimally invasive glaucoma surgeries (MIGSs) was intended to provide safe and modestly efficacious modalities for early intervention of mild-to-moderate glaucoma, with minimal trauma and rapid recovery. They were mainly ab interno procedures that reduce intraocular pressure by facilitating the aqueous outflow by bypassing the trabecular meshwork resistance, reinforcing the uveoscleral flow via the supraciliary space, and reducing aqueous production by the ciliary body. While the cumulating evidence helps shape the role of the available MIGS, the exponential new development and advancement in this field has expanded the territory of MIGS. Apart from developing subconjunctival MIGS filtration devices (Xen gel stent and PRESERFLO MicroShunt), there is a tendency to revisit the "traditional" MIGS for alternative use and to modify the procedures with consideration of the fundamental aqueous outflow physiology. Combined MIGS has also been suggested, based on the theory that their different mechanisms may provide additive or synergistic effects. The advancement of laser procedures is also promising and could supplement unmet needs along the glaucoma treatment algorithm. This review examines the broad array of MIGS, updates the recent findings, discusses their potential alternative applications, and explores future challenges.

Comparison of Short-term Visual Acuity Changes After Trabeculotomy ab Interno Using Trabectome and Trabeculectomy ab Externo

PURPOSE

To compare short-term visual acuity (VA) changes after trabeculotomy ab interno (TAI) using trabectome and trabeculectomy ab externo (TAE) performed on pseudophakic eyes.

DESIGN

A single-center retrospective study.

PARTICIPANTS

Patients with pseudophakic eyes who had primary open-angle glaucoma or exfoliation glaucoma and underwent TAI or TAE alone.

METHODS

Changes in intraocular pressure (IOP), medication score, Snellen VA, and the number of eyes with vision loss (loss of ≥ 2 Snellen lines) were evaluated at baseline, week 1, and months 1, 3, and 6. The risk factors for vision loss at 6 months postoperatively were analyzed in both groups.

MAIN OUTCOME MEASURES

Visual acuity changes.

RESULTS

A total of 112 eyes of 112 patients were examined: 46 in the TAI group and 66 in the TAE group. Intraocular pressure was significantly lower in both groups at each visit than at baseline. The TAI group had a significantly higher mean postoperative IOP than the TAE group. Medication scores in the TAI group were significantly different after 3 months compared with baseline; however, decreased significantly at all study visits in the TAE group. The mean VA in the TAI group did not decrease significantly at each visit. In the TAE group, it decreased significantly up to 3 months but was not significantly different at 6 months. At all study visits, the number of eyes with vision loss was significantly lower in the TAI group than in the TAE group. Only 2 eyes in the TAI group (4.3%) had vision loss at 6 months, which was caused by macular edema. In the TAE group, 13 eyes (19.7%) experienced vision loss at 6 months. In all cases, the presence of preoperative split fixation [odds ratio = 7.30, P < 0.05] and the occurrence of hypotony-related complications [odds ratio = 6.76, P < 0.05] within 6 months were risk factors for vision loss.

CONCLUSIONS

TAI lowered IOP less than TAE; however, there was less vision loss with TAI. For eyes with a target IOP in the mid-teens, TAI can be recommended as initial surgery.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosuremay be found in the Footnotes and Disclosures at the end of this article.

Five-Year Clinical Outcomes of Inferior Quadrant Trabectome Surgery for Open Angle Glaucoma

PRCIS

This retrospective study of 264 eyes having inferior quadrant trabectome surgery confirms its safety and relative effectiveness. Most patients however still require IOP-lowering agents, and a considerable proportion may need additional glaucoma surgery.

PURPOSE

To report outcomes from a large single-center cohort of inferiorly-applied trabectome surgery.

PATIENTS AND METHODS

Retrospective review of patients undergoing trabectome surgery for chronic open angle glaucoma (COAG) at the University Eye Clinic Bonn, Germany, from 2012 to 2020.

RESULTS

Two hundred sixty-four eyes of 206 patients with COAG were included. The mean review period was 45.43 (range 12-101) months. One hundred five eyes (39.8%) underwent standalone surgery, of which 74 were pseudophakic and 31 phakic. The mean preoperative IOP was 17.58 mm Hg (range 12-50 mm Hg). One hundred five eyes (39.8%) developed a 'failure event' according to pre-defined criteria at a mean interval of 14.8 months postoperative. In absolute terms, 211 patients (79.9%) had a long-term IOP >14 mm Hg at 7.6 months, 174 patients (65.9%) >16 mm Hg at 10.6 months, 127 patients (48.1%) >18 mm Hg at 10.9 months, and 77 patients (29.2%) >21 mm Hg at 11.1 months. Over a five-year period, overall mean IOP remained stable at 13 mm Hg. The majority of patients were still on glaucoma drops (the mean number reduced from 2.9 to 2.7 agents). Subgroup analyses showed that a higher preoperative IOP was a positive predictor for failure, whereas combined surgery (with phaco) had better IOP outcomes (16.5 mm Hg vs. 19.3 mm Hg, respectively). Forty-one patients (15.5%) developed minor complications: 22 had high postoperative IOP within 3 months, 11 developed a self-resorbing hyphema, and 6 had fibrinous uveitis.

CONCLUSIONS

Trabectome surgery is a safe and relatively effective procedure for lowering IOP, but most patients still need IOP-lowering agents, and a considerable proportion may need additional glaucoma surgery within a relatively short time. Inferior quadrant treatment may result in inferior IOP outcomes when compared with nasal quadrant surgery.

Mid-Term Results of Ab Interno Trabeculectomy among Japanese Glaucoma Patients

BACKGROUND

The evaluation of ab interno trabeculectomy, referred to as trabectome®, among Japanese patients is insufficient.

SUBJECTS AND METHODS

Japanese patients who underwent trabectome® at the University of Yamanashi Hospital were included. The investigated parameters were intraocular pressure (IOP), best corrected visual acuity, glaucoma medications, visual field, and corneal endothelial cell density. The success rate and its associated factors were investigated.

RESULTS

A total of 250 eyes from 197 patients were enrolled. The trabectome® significantly reduced IOP and glaucoma medications up to 48 months. Concomitant cataract extraction enhanced the reduction in IOP and glaucoma medications up to 42 months. At 36 months postoperatively, 40.8% satisfied IOP of the same or less than 18 mmHg or more than a 20% IOP reduction with the same or less use of glaucoma medications as preoperatively. Preoperative IOP and combined cataract extraction were significantly associated with the success rate. The trabectome® alone did not show a significant reduction in corneal endothelial cells. Eyes with postoperative transient IOP elevation and removal of anterior chamber hemorrhage were 11.2% and 1.2%, respectively. Twenty-four eyes (9.6%) underwent additional glaucoma surgeries.

CONCLUSIONS

The trabectome® could be considered an effective and safe surgery. Compared to trabectome® alone, combined cataract surgery was superior in lowering IOP and reducing glaucoma medications.

"Ab Interno" Surgery of the Schlemm's Canal in Postuveitic Glaucoma Patients

BACKGROUND

Patients with uveitis have a higher risk of developing glaucoma not only because of the disease by itself, but also because of the ongoing corticosteroid therapy. The pathogenesis of uveitic glaucoma is characterized by a complex of biochemical and cellular processes, as well as morphological changes in the trabecular meshwork. Treatment of secondary chronic glaucoma is challenging and often requires different approaches and solutions.

PURPOSE

To present the "ab interno" procedure of the Schlemm's canal (SC) performed with the help of TrabEx+ (MST, Redmond, WA, USA) in postuveitic glaucoma patients.

METHODS

The observed group included patients with postuveitic secondary glaucoma, which consisted of 12 pseudophakic patients (12 eyes). Patients are with intraocular pressure higher than 25 mmHg and on maximal local therapy. Due to insufficient conservative control on IOP, surgical solutions are needed. We describe a new, minimally invasive surgical procedure-the technique of the operation, the postoperative results and complications.

RESULTS

We present the achieved intraocular pressure (on the first day, 2 weeks, 1 month, 6, 8 12 and 18 months). The morphology of the trabecular area was demonstrated by gonioscopy. The effects of the therapy on the glaucoma progression, was evaluated with perimetry and OCT.

DISCUSSION

The following procedure is a minimally invasive procedure and provides good control of intraocular pressure. Aqueous veins in the conjunctiva are significantly preserved compared to conventional filtration trabeculectomy. This potentially modulates the physiological outflow pathways by ablating trabeculum strip the cause of increased outflow resistance-the inner wall of the SC.

CONCLUSION

Removal of the inner wall of the SC, using Trabex+ (MST, Redmond, WA, USA), demonstrates promising results in the selected patients with a minimally invasive nature.

Efficacy of Endotrabeculectomy (Trabecula Ablation Ab Interno with the Forceps) for Open-angle Glaucoma

Aim

To investigate the efficacy of endotrabeculectomy (ETE) performed either alone or combined with phacoemulsification (phaco) in patients with primary open-angle glaucoma (POAG).

Materials and methods

Investigations were done in two groups. The first group (38 patients, 38 eyes) with POAG underwent ETE, and the second group of 126 patients (126 eyes) with POAG and cataracts underwent ETE and phaco. The hypotensive effect of the surgery was evaluated.

Results

In the ETE group, the mean intraocular pressure (IOP) was reduced from 20.25 ± 3.30 to 14.94 ± 1.95 mm Hg (26.2% reduction, p < 0.001) at 12 months. The number of medications was reduced from 2.8 ± 1.0 to 1.5 ± 1.0 (p < 0.001) at 12 months after the surgery. In the phaco-ETE group, the mean IOP was reduced from 18.24 ± 3.20 to 14.83 ± 1.71 mm Hg (18.7% reduction, p < 0.001) at 12 months. The mean number of medications was reduced from 2.2 ± 1.1 to 1.0 ± 1.0 (p < 0.001) at 12 months after the surgery. The success rate defined as a final IOP of <16 mm Hg using the Kaplan-Meier curve at 12 months was 73.8%. There were no complications that led to a constant visual decrease.

Clinical significance

Our study shows that ETE is technically simple, gives the ability to remove trabecula in any quadrant, and effectively reduces IOP in patients with POAG.

Conclusion

Endotrabeculectomy (ETE) is a safe and relatively simple procedure that significantly reduces IOP. The minimally invasive nature of the ETE allows expanding indications for combined treatment of glaucoma and cataract.

How to cite this article

Novytskyy IY, Novytskyy MI. Efficacy of Endotrabeculectomy (Trabecula Ablation Ab Interno with the Forceps) for Open-angle Glaucoma. J Curr Glaucoma Pract 2023;17(1):15-21.

Minimally Invasive Glaucoma Surgery: Safety of Individual Devices

Primary open-angle glaucoma progression in those already on maximal medical therapy has traditionally been treated with trabeculectomy, a surgical procedure that carries a high degree of morbidity. In the last few decades, significant advances have been made in the field of minimally invasive glaucoma surgery (MIGS) devices, which aim to defer or prevent trabeculectomy via less arduous surgical techniques in certain types of glaucoma. Although reviews have been published examining the efficacy of various MIGS techniques, no article synthesises the comparative safety of all available devices. We performed a literature review examining the safety of MIGS devices. Fifteen devices were included, variously attempting to increase aqueous outflow through the trabecular meshwork or the suprachoroidal space, shunting into the subconjunctival space, or reducing aqueous production through ciliary body ablation. Notably, the earliest product attempting to increase outflow to the suprachoroidal space, Alcon's CyPass Micro-Stent, was withdrawn from the market due to concerns regarding increased corneal endothelial cell loss at five years post-implantation. All other devices were described as well-tolerated, with the most common adverse effects including hyphaema, intraocular pressure spikes, and device migration or obstruction. MIGS devices are purported to be uniformly safe, and many studies report no statistically significant increased complications beyond those associated with cataract surgery alone. It is important to note, however, the generally poor quality of current studies, with a dearth of randomised, or even prospective, data, and a large proportion of studies funded by device producers.

Outcomes of ab-interno irrigating goniectomy with trabectome in primary and secondary glaucoma from a single center in India

Purpose

This study was done to report intermediate-term outcomes of irrigating goniectomy with trabectome (trabectome) surgery among different types of glaucoma eyes from a single center in India using a cross-sectional, longitudinal, observational study design.

Methods

Fifty-three patients (58 eyes) with glaucoma who underwent irrigating goniectomy with trabectome between January 2019 and February 2020 were included. Pre-operative data included age, gender, eye laterality, specific diagnosis, number of anti-glaucoma medications (AGMs), prior glaucoma surgeries, visual acuity, and intraocular pressure (IOP) on medical treatment. Post-operative data included IOP changes during the follow-up till 1-year, number of AGMs, any complications, or additional surgical intervention required. Success was defined as IOP ≤ 21 mmHg and ≥ 20% reduction of IOP from pre-operative IOP with no additional glaucoma surgery.

Results

The cohort included 58 eyes (male 53.4% and female 46.6%) ranging from 0.6 to 81 years of age. The average baseline IOP was 23.4 ± 10.2 mmHg and reduced significantly with surgery to 14.1 ± 5.3 mmHg at 1-year follow-up. The AGMs reduced from 2.4 ± 1.4 pre-surgery to 1.6 ± 1.4 at 1-year follow-up. Four eyes required additional glaucoma surgeries for IOP control. The success rate of trabectome with phacoemulsification (88%) was discernibly higher than with trabectome alone (67%). Intra-operatively, significant blood reflux was noticed in 27 eyes, of which only one required tamponading with a viscoelastic agent.

Conclusion

This study concludes that irrigating goniectomy with trabectome has good efficacy and safety in both pediatric and adult cases of glaucoma in terms of IOP control, reduction in AGMs, and low incidence of complications in the Indian population.

Early Results of Irrigating Goniectomy With TrabEx+: A Novel Device for the Treatment of Open-angle Glaucoma

PRCIS

Irrigating goniectomy with the TrabEx+ device can lower intraocular pressure (IOP) in patients with glaucoma, as a standalone procedure or combined with cataract surgery.

PURPOSE

The aim was to describe the efficacy and safety of irrigating goniectomy performed using the TrabEx+ device, either as a standalone procedure or combined with cataract surgery, in eyes with medically treated open-angle glaucoma.

METHODS

A retrospective case series of eyes treated by a single surgeon at a single UK teaching hospital. Data was collected at follow-up visits at 1 week, 3, 6, 12, 18, and 24 months postoperatively. Primary outcomes included IOP and glaucoma medication reduction after surgery. Proportion of eyes achieving >20% IOP reduction, IOP <21 mm Hg, and no reoperation were classified as surgical success.

RESULTS

Seventy-three consecutive eyes of 64 patients (mean age 68.4±13.7 y) were enrolled. 62% were treated as combined procedures with cataract surgery. Overall, mean IOP decreased from 31.3±7.3 to 20.9±10.4 mm Hg at the latest follow-up (34% reduction) (P<0.001) at the latest follow-up (16.1±10.3 mo) with mean preoperative medications decreased from 2.9±1.2 to 1.9±1.3 (P<0.001). 73% met the definition of success at latest follow-up. Postoperative complications were recorded including hyphaema (17%), uveitis (3%), hypotony (1%), and persistent vitreous hemorrhage (1%). Eighteen percent required reoperation because of treatment failure.

CONCLUSION

TrabEx+ appears to be effective in lowering IOP and medication with or without cataract surgery. However, long-term safety and efficacy will be better understood in a prospective study with longer follow-up.

Endocyclophotocoagulation combined with phacoemulsification in surgically naive primary open-angle glaucoma: three-year results

OBJECTIVE

To assess the safety and efficacy of endocyclophotocoagulation with phacoemulsification (phaco-ECP) in surgically naive, primary open-angle glaucoma (POAG).

METHODS

A retrospective case series of patients undergoing phaco-ECP between 2007 and 2017 at a single centre in London, UK. The primary outcome was intraocular pressure (IOP). Secondary outcomes were visual acuity, visual field global indices, topical medications and surgical complications. Failure criteria were: (1) IOP > 21 mmHg or <20% reduction at two consecutive visits, (2) IOP <5 mmHg and (3) further IOP-lowering surgery.

RESULTS

Eighty-three eyes from 83 patients were eligible. Pre-operatively, mean IOP (±SD) was 18.4 ± 5.2 mmHg. The mean number of topical agents (±SD) was 2.7 ± 0.9. Mean IOP (±SD) significantly reduced to 14.3 ± 4.7 at 1 year, 14.1 ± 4.0 at 2 years and 13.6 ± 3.7 at 3 years (p < 0.0001). Topical medications were significantly reduced to 1.3 ± 1.2 at 1 year, 1.7 ± 1.2 at 2 years and 1.8 ± 1.3 at 3 years (p < 0.0001). Annual IOP 'survival' was 70%, 54% and 45% at year 1, 2 and 3, respectively. Complications included uveitis (6%), macular oedema (2%), IOP spikes (1%) and corneal decompensation (1%) with no episodes of hypotony or retinal detachment. One patient underwent filtration surgery within 3 years (1%).

CONCLUSION

Phaco-ECP facilitates significant IOP lowering and reduction of medication burden in surgically naive POAG requiring cataract extraction. The procedure is relatively safe and without the use of implants and their associated risks.

Comparison of effectiveness and complications in trabeculotomy with phacoemulsification between ab externo and ab interno using a spatula-shaped microhook

To compare the short-term surgical effectiveness and safety profile of trabeculotomy ab externo and ab interno with microhook in terms of the recovery of visual acuity. A retrospective chart review was performed on patients who underwent trabeculotomy combined with phacoemulsification and lens implantation at Asahi General Hospital, with 6 months of follow-up. The patients treated by trabeculotomy were classified into two groups depending on the surgical procedures: ab interno with Tanito microhook (TMH) and ab externo with rigid probe trabeculotome (LOT). The demographics, preoperative and postoperative intraocular pressure (IOP), number of medications (Med), best-corrected visual acuity (BCVA), surgical-induced astigmatism (SIA), and postoperative complications were analyzed at pre-operation, and 1 week and 1–6 months post-operation. Fifty-two eyes of 38 Japanese patients underwent TMH and 42 eyes of 32 patients underwent LOT. The decreases in IOP and Med from the baseline were significant at all time points in both groups (p < 0.001), but there were no significant differences between the two groups. BCVA improved significantly in TMH and LOT after the operation (p < 0.001). BCVA and SIA significantly improved, mostly at 1 week in TMH, compared with LOT (p = 0.02 and 0.003). Hyphema and IOP spike exceeding 30 mmHg (spike) occurred in 11% and 6% of participants in TMH, and 33% and 26% of participants in LOT, respectively. Hyphema and IOP spike occurred more frequently in the LOT than in the TMH group (p = 0.01 and 0.005). Ab interno trabeculotomy showed similar IOP-lowering effects as ab externo, but had less postoperative complications.

Intraocular Pressure Reduction by Femtosecond Laser Created Trabecular Channels in Perfused Human Anterior Segments

Purpose

This study investigated the initial feasibility of using femtosecond laser trabeculotomy (FLT) to create open channels through the trabecular meshwork into Schlemm's canal to lower intraocular pressure (IOP) in a perfused anterior segment model.

Methods

Human anterior segments (12 eyes) were assigned to either treatment (n = 6) or sham treatment (n = 6) groups. Both groups were perfused until a baseline IOP was recorded upon which a direct FLT treatment or a sham treatment was administered. IOP was recorded before and after the treatment. Spectral domain optical coherence tomography and second harmonic generation imaging we used to investigate the FLT channels.

Results

In the FLT group, there was a significant mean decrease in the IOP of 22% compared with the pre-FLT IOP (7.13 ± 2.95 mm Hg to 5.34 ± 1.62 mm Hg; P < 0.05). In the control group, the post-sham IOP remained relatively unchanged compared with the pre-sham IOP (6.39 ± 3.69 mm Hg to 6.67 ± 4.12 mm Hg).

Conclusions

The results of this study indicate that FLT treatment can significantly decrease the IOP in a perfusion model and may provide a potential noninvasive treatment option for primary open angle glaucoma.

Translational Relevance

Investigating the use of femtosecond lasers for photodisrupting the trabecular meshwork can lead to a clinically relevant alternative to current glaucoma procedures.

Effectiveness and limitations of minimally invasive glaucoma surgery targeting Schlemm's canal

Glaucoma surgery is performed to lower intraocular pressure (IOP); ideally, the IOP reduction is safely maintained for an extended period of time. Although trabeculectomy was considered the gold standard for glaucoma surgery for many years because of its effective IOP reduction, yet now it is considered unsafe because of serious complications. In recent years, minimally invasive glaucoma surgery (MIGS), which emphasizes safety and can be performed rapidly, has become widespread. Because MIGS does not involve conjunctival incisions, patients can undergo future trabeculectomy. If IOP reduction can be maintained safely, the number of anti-glaucoma drops can be reduced and visual function maintained, good outcomes for patients with glaucoma. Currently, many types of MIGS approved in Japan are reported to yield relatively good results, with targets of approximately 15-19 mmHg. However, the IOP-lowering effects of MIGS are limited. In procedures targeting Schlemm's canal, it is difficult to lower IOP beyond episcleral venous pressure. In some instances, a beneficial effect cannot be achieved if function is reduced beyond the collector channel. There are many unclear aspects regarding long-term outcomes following MIGS. Notably, investigation is ongoing to determine which patients are likely to benefit most from surgery. Based on previous reports, this review describes the characteristics and results of MIGS, approved in Japan, as well as underlying factors that affect the preoperative predictions and outcomes of the surgical procedure.

Ab Interno Trabeculotomy: Key Prognostic Factors

PRéCIS:: The preoperative factors associated with a decreased survival rate of ab interno trabeculotomy (AbIT) perfomed using a Trabectome in open-angle glaucoma were selective laser trabeculoplasty (SLT) performed previously and axial length (AL) over 23.82 mm.

PURPOSE

The purpose of this study was to find preoperative factors that predict outcomes of AbIT by a Trabectome.

MATERIALS AND METHODS

This retrospective single-center cohort study involved consecutive patients with primary open-angle glaucoma and exfoliation glaucoma treated at Helsinki University Hospital with AbIT with preoperative intraocular pressure (IOP) ≥18 mm Hg and follow-up of at least 1 year. Success was defined as lowering of their IOP by at least 20% from baseline or reduction in glaucoma medications without any rise in IOP above baseline, and no subsequent glaucoma surgery.

RESULTS

Of the total 72 eyes of 67 patients, 51 eyes had exfoliation glaucoma and 21 had primary open-angle glaucoma. Mean preoperative IOP was 25.2±5.3 mm Hg, with a mean of 3.2±1.2 glaucoma medications. In the multivariable model, a history of preoperative SLT and higher preoperative AL had hazard ratios of 2.99 [95% confidence interval (CI): 1.26-7.10] and 1.53 (95% CI: 1.12-2.09) with statistical significance (P=0.013 and 0.007). The statistically significant cutoff point was 23.82 mm in AL in relation to the success rate, with success times taken into account (P<0.001). AL over 23.82 mm had hazard ratio of 5.75 (95% CI: 2.57-12.87, P<0.001).

CONCLUSION

Previous SLT and AL over 23.82 mm reduce survival after AbIT.

Minimally Invasive Glaucoma Surgery: Where Is the Evidence?

PURPOSE

The last decade has witnessed an unprecedented growth in glaucoma treatment options through the introduction of minimally invasive glaucoma surgeries (MIGS). The aim of the present review is to provide an understanding of the currently available MIGS and to examine what data are currently available to guide treatment choice.

DESIGN

Meta-analysis and systematic review of randomized and non-randomized control trials.

METHODS

Out of 2567 articles identified, a total of 77 articles were retained for analysis, including 28 comparative studies and 12 randomized control trials. Overall, 7570 eyes were included. When data permitted, the weighted mean difference in intraocular pressure reduction was calculated for comparison purposes.

RESULTS

Weighted mean intraocular pressure reductions from all analyzed studies were: 15.3% (iStent), 29.1% (iStent inject), 36.2% (ab interno canaloplasty), 34.4% (Hydrus), 36.5% (gonioscopically-assisted transluminal trabeculotomy), 24.0% (trabectome), 25.1% (Kahook dual blade), 30.2% (Cypass), 38.8% (XEN), and 50.0% (Preserflo).

CONCLUSIONS

One of the advantages of the heterogenous range of available MIGS options is the chance to tailor therapy in an individualized manner. However, high-quality data are required to make this choice more than an educated guess. Overall, this review confirms the efficiency of assessed MIGS compared with standalone phacoemulsification, but it highlights that only few studies compare different MIGS techniques and even fewer assess MIGS against criterion standard treatments. Current evidence, while non-negligible, is mostly limited to heterogenous nonrandomized studies and uncontrolled retrospective comparisons, with few quality randomized control trials. We suggest that future research should be comparative and include relevant comparators, standardized to report key outcome features, long-term to assess sustainability and late complications, and ideally randomized.