- Email: [email protected]
27-Gauge Vitrectomy
Advances in Ophthalmology and Optometry 1 (2016) 129–134
ADVANCES IN OPHTHALMOLOGY AND OPTOMETRY
27-Gauge Vitrectomy The Future of Posterior Segment Surgery? Alan Sheyman, MDa,*, Albert Lin, BSa, Ronni M. Lieberman, MDb a
Department of Ophthalmology, Northwestern University Feinberg School of Medicine, 645 North Michigan Avenue, Suite 440, Chicago, IL 60611, USA; bDepartment of Ophthalmology, Icahn School of Medicine at Mount Sinai, 1 Gustave Levy Place, New York, NY 10029, USA
Keywords
Vitrectomy 27-gauge 25-gauge 23-gauge Macular surgery Small gauge vitrectomy
Key points
27-Gauge vitrectomy instrumentation offers smaller wound construction, increasing the probability of sutureless closure, as well as decreased postoperative trauma and inflammation.
Small-caliber approaches still pose engineering challenges relating to reduced flow rates and instrument capabilities.
Given the continuing trend in posterior segment surgery toward smaller-caliber instruments, it is prudent to understand the current capabilities of the 27-gauge system and to determine whether the transition to 27-gauge surgery represents a natural, inevitable evolution of ongoing advances in surgical technology.
INTRODUCTION The road to minimally invasive vitreous surgery Contemporary small-gauge vitrectomy, also known as minimally invasive vitreous surgery (MIVS), reflects decades of innovation by ophthalmic surgeons who continuously improved on milestone advances in surgical instrumentation and technique. Robert Machemer and colleagues [1] first developed closed globe pars plana vitrectomy in the 1970s, which required passing a vitreous The authors have nothing to disclose.
*Corresponding author. E-mail address: [email protected] 2452-1760/16/$ – see front matter http://dx.doi.org/10.1016/j.yaoo.2016.03.014
Ó 2016 Elsevier Inc. All rights reserved.
130
SHEYMAN, LIN, & LIEBERMAN
infusion suction cutter through a 17-gauge sclerotomy port. The initial cut rate was a mere 60 cuts per minute (cpm). It was not long, however, before other surgeons began improving on Machemer’s system. Twenty-gauge surgery developed a few years later, and in 1996, Chen [2] described for the first time a transconjunctival approach that allowed for sutureless, self-sealing sclerotomies that shortened surgical time and decreased traumatic injury. Then, Fujii and colleagues [3] introduced a complete 25-gauge sutureless vitrectomy system in 2002 that better facilitated instrument exchange using microtrocar cannulas. Although the infusion and aspiration rates of the 25-gauge instruments could not match those of the 20-gauge vitrectomy system, the mean operative time decreased by 9 minutes. 25-Gauge also had the further advantage over 20-gauge of hastening postoperative recovery, thanks to decreased overall surgical time and postoperative inflammation [4]. Despite these advantages, however, 25-gauge was not without its critics. In particular, some surgeons objected to the excessive flexibility of the instruments that precluded performing more complicated tasks in the peripheral retina. In 2005, Eckhardt [5] introduced 23-gauge instrumentation that provided increased instrument stiffness and stability along with the potential for sutureless incisions. Unfortunately, multiple reports of increased postoperative hypotony rates with 23-gauge and 25-gauge systems compared with 20-gauge were published, effectively questioning whether these incisions were truly ‘‘sutureless’’ [6]. Further advances in 23-gauge and 25-gauge vitrectomy instrumentation allowed for the development of higher flow rates, faster vitrectomy cutter speeds, and improved duty cycles. In addition, because 23-gauge and 25-gauge instruments featured longer probes, with the cutting mouth positioned more toward the tip of the vitrector, it became easier for surgeons to use the vitrector directly to dissect the membrane, using high cutting speed and low suction [7]. Surgeons also turned their attention to achieving actual sutureless wound construction of the pars plana through using multiplanar incisions and single-step trocar insertion techniques, and displacing the external conjunctival wound from the internal sclerotomy to promote self-sealing [8]. With sutureless sclerotomies, the risk of corneal topographic changes and associated astigmatism also is reduced [7]. These advances paved the road for 27-gauge vitrectomy, which is the smallest vitrectomy system commercially available today. Twenty-seven gauge vitrectomy Oshima and colleagues [9] in 2010 described 31 surgical cases involving the posterior segment, including macular holes, diabetic vitreous hemorrhages, tractional retinal detachments, epiretinal membranes (ERMs), and vitreous opacifications that were operated on with 27-gauge instrumentation. Not only was anatomic success achieved in all cases without the need for sclerotomy enlargement, but no cases of hypotony were reported. The mean case time was 34 minutes. The smaller diameter of the instruments resulted in reduced infusion and aspiration rates compared with 25-gauge, however the
27-GAUGE VITRECTOMY
131
duty cycle performed better at 1500 cpm for 27-gauge. Sutureless vitreous biopsies using a sharp-tipped, short-shaft 27-gauge vitrector were also made possible and described in a later study [10]. ADVANTAGES Overall, 27-gauge instrumentation seeks to induce less postoperative trauma, diminish external scarring, avoid suture-induced astigmatism, and achieve better recovery and comfort for the patient compared with 25-gauge and 23-gauge. The reduced caliber also may theoretically diminish the rates of hypotony and endophthalmitis, although variables such as wound construction and trocar blade selection also play a role in postoperative complication rates [7]. Here, current surgical advantages for 27-gauge are reviewed, including improvements to the vitrector and developments in intraoperative optical coherence tomography. Surgical indications 27-Gauge instruments are currently being used for a wide range of posterior segment conditions, including but not limited to macular hole, macular pucker, vitreous opacities, vitreomacular traction, tractional retinal detachments, and vitreous biopsy [7]. Although the literature for surgical outcomes using 27gauge instrumentation is not robust, the 27-gauge system has demonstrated equal surgical outcomes and rates of intraoperative complications for ERM vitrectomy when compared with 25-gauge, implying that the 27-gauge system can not only achieve 25-gauge outcomes but also potentially do so with greater efficiency and efficacy in the future as the technology advances [11]. Other early studies for 27-gauge also have shown favorable outcomes, along with low rates of intraoperative and postoperative complications, across a wider breadth of surgical indications. A study by Khan and colleagues [12] on a cohort of 95 eyes showed no intraoperative complications, no conversions to lower-gauge instrumentation, and a reported 1.1% of eyes requiring suturing of the sclerotomy incisions. Reported complication rates were ocular hypertension in 8.4%, transient hypotony in 5.3%, and vitreous hemorrhage in 5.3%. No cases of endophthalmitis, retinal tears, or choroidal detachments were reported at 90 days postoperatively. In addition, Yamane and colleagues [13] reported a technique for sutureless 27-gauge needle-guided intrascleral intraocular lens (IOL) implantation that provided good fixation and reliable wound closure. The precision of 27-gauge instrumentation allowed the surgeons to thread the IOL haptics directly into scleral tunnels, obviating the need for scleral sutures. Further refinement of established surgical procedures is expected afforded by finer tissue manipulation using 27-gauge technique. Improved vitrector speed and precision Perhaps one of the more impressive developments with the advent of 27-gauge technology has been faster cutting speeds: 5000 cpm is now routine; 7500 cpm is becoming common, and 16,000 cpm is available [14]. Theoretically, increasing
132
SHEYMAN, LIN, & LIEBERMAN
the cut rate reduces the viscosity of the vitreous under suction by reducing the amount of traction that the cutter places on the retina, thereby decreasing the risk of iatrogenic breaks. This feature, coupled with the smaller cutter head of 27-gauge, allows surgeons to remove vitreous and membranes off the surface of the retina at a very small distance from the retinal surface while minimizing the risk of incarceration. An in vitro study of the membrane attraction capabilities of 27-gauge, 25-gauge, and 23-gauge probes found that the 27-gauge probe had the shortest attraction distance (ie, greater membrane dissection precision), which should allow for improved access to small tissue planes [15]. However, there is concern that ultrahigh cut rates require repeated re-engaging of tissue near the retina, which may slow down tissue removal [14]. Intraoperative optical coherence tomography Intraoperative optical coherence tomography (iOCT) is currently being explored as a tool for surgeons to obtain real-time imaging that may facilitate improved surgical decision-making. A study by Ehlers and colleagues [16] in 2014 reported the results of iOCT use on a cohort of 518 eye cases over 24 months, showing that iOCT informed surgical decision-making in 63 of the 146 EPM peeling procedures (43%). No adverse events were reported with the use of iOCT, and the median time that surgery was paused to perform iOCT was 4.9 minutes per scan session. Another study by the same investigators on iOCT use during vitrectomy surgery for dense vitreous hemorrhage surgery showed that multiple eyes had structural abnormalities, eg ERMs and macular edema, that were revealed intraoperatively. This finding implies that iOCT has the potential to provide real-time information that may impact surgical management and patient outcomes [17]. With regards to the concurrent use of 27-gauge and iOCT, the literature remains quite sparse. However, a case report from 2015 discussing iOCTassisted 27-gauge MIVS showed that 27-gauge demonstrated minimal shadow casting on the underlying tissues as compared with 25-gauge and 23-gauge, providing excellent intraoperative visualization of retinal tissues [18]. This finding implies that 27-gauge and iOCT may be synergistic developments, each contributing unique but complementary enhancements to the retina surgeon’s repertoire. CHALLENGES Despite the myriad advantages that 27-gauge potentially offers to the techsavvy surgeon, there remain some challenges with the technology that require addressing. Given the reduced inner diameter of the 27-gauge vitrector compared with 25-gauge (0.275 mm vs 0.347 mm, respectively), maintaining sufficient aspiration and infusion rates remains an engineering challenge [7,12]. A cursory analysis of the difference in flow rates can be made using Poiseuille’s law, which shows that decreasing the radius by 21% (ie, 25-gauge to 27-gauge) given constant pressure decreases the volume flow rate by 61% [14]. With that said, the
27-GAUGE VITRECTOMY
133
reduced flow may be partially mitigated by the faster cutting speeds and increased duty cycles of 27-gauge vitrectomy as well as increased driving pressure, although further studies are required to validate this claim [12]. In addition, the relatively short length of currently available probes complicates the use of 27 gauge in highly myopic eyes. SUMMARY The use of smaller-gauge sutureless vitrectomy systems has reduced surgical trauma while maintaining excellent patient outcomes, resulting in better postoperative recovery and improved patient satisfaction. The 27-gauge vitrector is the most recent development in this line of technological innovation and has a similar rigidity to 25-gauge instruments and sufficient cutting and aspiration capabilities. The 2015 Preferences and Trends survey of the American Society of Retina Specialists [19] showed that 23% of US-based surgeons do not anticipate using 27-gauge vitrectomy in the near future. However, 51% of responders reported that they intend to use 27-gauge in 1% to 50% of their cases, and 22.3% said that they intend to use 27-gauge in greater than 50% of their cases. Of the surgeons who use 27-gauge, an overwhelming majority (76% in the United States, 80.6% internationally) prefer the Alcon Constellation vitrectomy system. Current data show that 27-gauge vitrectomies show comparable outcomes and complication rates compared with previous generations of instruments, on top of demonstrating novel applications specific to 27-gauge. Furthermore, the increased precision of tissue manipulation with 27-gauge, along with the development of iOCT, all point toward better outcomes with smaller-gauge vitrectomy in the future. Although a learning curve will be required for the adoption of 27-gauge surgery by the retinal community, it is likely that the transition to 27-gauge surgery will speak for itself if instrumentation, as well as outcomes, continues to demonstrate benefits for patients and surgeons alike. References [1] Machemer R, Buettner H, Norton EW, et al. Vitrectomy: a pars plana approach. Trans Am Acad Ophthalmol Otolaryngol 1971;7:813–20. [2] Chen JC. Sutureless pars plana vitrectomy through self-sealing sclerotomies. Arch Ophthalmol 1996;114(10):1273–5. [3] Fujii GY, De Juan E Jr, Humayun MS, et al. A new 25-gauge instrument system for transconjunctival sutureless vitrectomy surgery. Ophthalmology 2002;109:1807–12. [4] Lakhanpal RR, Humayun MS, de Juan E Jr, et al. Outcomes of 140 consecutive cases of 25-gauge transconjunctival surgery for posterior disease. Ophthalmology 2005;112: 817–24. [5] Eckhardt C. Transconjunctival sutureless 23-gauge vitrectomy. Retina 2005;25:208–11. [6] Kellner L, Wimpissinger B, Stolba U, et al. 25-Gauge vs 20-gauge system for pars plana vitrectomy: a prospective randomised clinical trial. Br J Ophthalmol 2007;91:945–8. [7] Martinez-Toldos JJ, Hoyos JE. Step by step vitrectomy. 2nd edition. New Delhi: Jaypee Brothers Medical Publishers Ltd; 2013. p. 184–201. [8] Khanduja S, Kakkar A, Majumdar S, et al. Small gauge vitrectomy: recent update. Oman J Ophthalmol 2013;6(1):3–11.
134
SHEYMAN, LIN, & LIEBERMAN
[9] Oshima Y, Wakabayashi T, Sato T, et al. A 27-gauge instrument system for transconjunctival sutureless microincision vitrectomy surgery. Ophthalmology 2010;117(1):93–102. [10] Oshima Y, Wakabayashi T, Ohguro N, et al. 27-gauge sharp-tip short-shaft pneumatic vitreous cutter for transconjunctival sutureless vitreous biopsy. Retina 2011;31(2):419–21. [11] Mitsui K, Kogo J, Takeda H, et al. Comparative study of 27-gauge vs 25-gauge vitrectomy for epiretinal membrane. Eye (Lond) 2016. [Epub ahead of print]. [12] Khan MA, Shahlaee A, Toussaint B, et al. Outcomes of 27 gauge microincision vitrectomy surgery for posterior segment disease. Am J Ophthalmol 2016;161:36–43.e2. [13] Yamane S, Inoue M, Arakawa A, et al. Sutureless 27-gauge needle-guided intrascleral intraocular lens implantation with lamellar scleral dissection. Ophthalmology 2014;121(1): 61–6. [14] Garg SJ, Fineman MS. Do faster cutting speeds really make a difference? American Society of Retina Specialists; 2015. Accessed January 9, 2016. [15] Dugel PU, Abulon DJ, Dimalanta R. Comparison of attraction capabilities associated with high-speed, dual-pneumatic vitrectomy probes. Retina 2015;35(5):915–20. [16] Ehlers JP, Dupps WJ, Kaiser PK, et al. The Prospective Intraoperative and Perioperative Ophthalmic ImagiNg with Optical CoherEncE TomogRaphy (PIONEER) study: 2-year results. Am J Ophthalmol 2014;158(5):999–1007. [17] Ehlers JP, Griffith JF, Srivastava SK. Intraoperative optical coherence tomography during vitreoretinal surgery for dense vitreous hemorrhage in the pioneer study. Retina 2015;35(12): 2537–42. [18] Kunikata H, Nakazawa T. Intraoperative optical coherence tomography-assisted 27-gauge vitrectomy in eyes with vitreoretinal diseases. Case Rep Ophthalmol 2015;6(2):216–22. [19] American Society of Retina Specialist Annual Preferences and Trends Survey. 2015.
ADVANCES IN OPHTHALMOLOGY AND OPTOMETRY
27-Gauge Vitrectomy The Future of Posterior Segment Surgery? Alan Sheyman, MDa,*, Albert Lin, BSa, Ronni M. Lieberman, MDb a
Department of Ophthalmology, Northwestern University Feinberg School of Medicine, 645 North Michigan Avenue, Suite 440, Chicago, IL 60611, USA; bDepartment of Ophthalmology, Icahn School of Medicine at Mount Sinai, 1 Gustave Levy Place, New York, NY 10029, USA
Keywords
Vitrectomy 27-gauge 25-gauge 23-gauge Macular surgery Small gauge vitrectomy
Key points
27-Gauge vitrectomy instrumentation offers smaller wound construction, increasing the probability of sutureless closure, as well as decreased postoperative trauma and inflammation.
Small-caliber approaches still pose engineering challenges relating to reduced flow rates and instrument capabilities.
Given the continuing trend in posterior segment surgery toward smaller-caliber instruments, it is prudent to understand the current capabilities of the 27-gauge system and to determine whether the transition to 27-gauge surgery represents a natural, inevitable evolution of ongoing advances in surgical technology.
INTRODUCTION The road to minimally invasive vitreous surgery Contemporary small-gauge vitrectomy, also known as minimally invasive vitreous surgery (MIVS), reflects decades of innovation by ophthalmic surgeons who continuously improved on milestone advances in surgical instrumentation and technique. Robert Machemer and colleagues [1] first developed closed globe pars plana vitrectomy in the 1970s, which required passing a vitreous The authors have nothing to disclose.
*Corresponding author. E-mail address: [email protected] 2452-1760/16/$ – see front matter http://dx.doi.org/10.1016/j.yaoo.2016.03.014
Ó 2016 Elsevier Inc. All rights reserved.
130
SHEYMAN, LIN, & LIEBERMAN
infusion suction cutter through a 17-gauge sclerotomy port. The initial cut rate was a mere 60 cuts per minute (cpm). It was not long, however, before other surgeons began improving on Machemer’s system. Twenty-gauge surgery developed a few years later, and in 1996, Chen [2] described for the first time a transconjunctival approach that allowed for sutureless, self-sealing sclerotomies that shortened surgical time and decreased traumatic injury. Then, Fujii and colleagues [3] introduced a complete 25-gauge sutureless vitrectomy system in 2002 that better facilitated instrument exchange using microtrocar cannulas. Although the infusion and aspiration rates of the 25-gauge instruments could not match those of the 20-gauge vitrectomy system, the mean operative time decreased by 9 minutes. 25-Gauge also had the further advantage over 20-gauge of hastening postoperative recovery, thanks to decreased overall surgical time and postoperative inflammation [4]. Despite these advantages, however, 25-gauge was not without its critics. In particular, some surgeons objected to the excessive flexibility of the instruments that precluded performing more complicated tasks in the peripheral retina. In 2005, Eckhardt [5] introduced 23-gauge instrumentation that provided increased instrument stiffness and stability along with the potential for sutureless incisions. Unfortunately, multiple reports of increased postoperative hypotony rates with 23-gauge and 25-gauge systems compared with 20-gauge were published, effectively questioning whether these incisions were truly ‘‘sutureless’’ [6]. Further advances in 23-gauge and 25-gauge vitrectomy instrumentation allowed for the development of higher flow rates, faster vitrectomy cutter speeds, and improved duty cycles. In addition, because 23-gauge and 25-gauge instruments featured longer probes, with the cutting mouth positioned more toward the tip of the vitrector, it became easier for surgeons to use the vitrector directly to dissect the membrane, using high cutting speed and low suction [7]. Surgeons also turned their attention to achieving actual sutureless wound construction of the pars plana through using multiplanar incisions and single-step trocar insertion techniques, and displacing the external conjunctival wound from the internal sclerotomy to promote self-sealing [8]. With sutureless sclerotomies, the risk of corneal topographic changes and associated astigmatism also is reduced [7]. These advances paved the road for 27-gauge vitrectomy, which is the smallest vitrectomy system commercially available today. Twenty-seven gauge vitrectomy Oshima and colleagues [9] in 2010 described 31 surgical cases involving the posterior segment, including macular holes, diabetic vitreous hemorrhages, tractional retinal detachments, epiretinal membranes (ERMs), and vitreous opacifications that were operated on with 27-gauge instrumentation. Not only was anatomic success achieved in all cases without the need for sclerotomy enlargement, but no cases of hypotony were reported. The mean case time was 34 minutes. The smaller diameter of the instruments resulted in reduced infusion and aspiration rates compared with 25-gauge, however the
27-GAUGE VITRECTOMY
131
duty cycle performed better at 1500 cpm for 27-gauge. Sutureless vitreous biopsies using a sharp-tipped, short-shaft 27-gauge vitrector were also made possible and described in a later study [10]. ADVANTAGES Overall, 27-gauge instrumentation seeks to induce less postoperative trauma, diminish external scarring, avoid suture-induced astigmatism, and achieve better recovery and comfort for the patient compared with 25-gauge and 23-gauge. The reduced caliber also may theoretically diminish the rates of hypotony and endophthalmitis, although variables such as wound construction and trocar blade selection also play a role in postoperative complication rates [7]. Here, current surgical advantages for 27-gauge are reviewed, including improvements to the vitrector and developments in intraoperative optical coherence tomography. Surgical indications 27-Gauge instruments are currently being used for a wide range of posterior segment conditions, including but not limited to macular hole, macular pucker, vitreous opacities, vitreomacular traction, tractional retinal detachments, and vitreous biopsy [7]. Although the literature for surgical outcomes using 27gauge instrumentation is not robust, the 27-gauge system has demonstrated equal surgical outcomes and rates of intraoperative complications for ERM vitrectomy when compared with 25-gauge, implying that the 27-gauge system can not only achieve 25-gauge outcomes but also potentially do so with greater efficiency and efficacy in the future as the technology advances [11]. Other early studies for 27-gauge also have shown favorable outcomes, along with low rates of intraoperative and postoperative complications, across a wider breadth of surgical indications. A study by Khan and colleagues [12] on a cohort of 95 eyes showed no intraoperative complications, no conversions to lower-gauge instrumentation, and a reported 1.1% of eyes requiring suturing of the sclerotomy incisions. Reported complication rates were ocular hypertension in 8.4%, transient hypotony in 5.3%, and vitreous hemorrhage in 5.3%. No cases of endophthalmitis, retinal tears, or choroidal detachments were reported at 90 days postoperatively. In addition, Yamane and colleagues [13] reported a technique for sutureless 27-gauge needle-guided intrascleral intraocular lens (IOL) implantation that provided good fixation and reliable wound closure. The precision of 27-gauge instrumentation allowed the surgeons to thread the IOL haptics directly into scleral tunnels, obviating the need for scleral sutures. Further refinement of established surgical procedures is expected afforded by finer tissue manipulation using 27-gauge technique. Improved vitrector speed and precision Perhaps one of the more impressive developments with the advent of 27-gauge technology has been faster cutting speeds: 5000 cpm is now routine; 7500 cpm is becoming common, and 16,000 cpm is available [14]. Theoretically, increasing
132
SHEYMAN, LIN, & LIEBERMAN
the cut rate reduces the viscosity of the vitreous under suction by reducing the amount of traction that the cutter places on the retina, thereby decreasing the risk of iatrogenic breaks. This feature, coupled with the smaller cutter head of 27-gauge, allows surgeons to remove vitreous and membranes off the surface of the retina at a very small distance from the retinal surface while minimizing the risk of incarceration. An in vitro study of the membrane attraction capabilities of 27-gauge, 25-gauge, and 23-gauge probes found that the 27-gauge probe had the shortest attraction distance (ie, greater membrane dissection precision), which should allow for improved access to small tissue planes [15]. However, there is concern that ultrahigh cut rates require repeated re-engaging of tissue near the retina, which may slow down tissue removal [14]. Intraoperative optical coherence tomography Intraoperative optical coherence tomography (iOCT) is currently being explored as a tool for surgeons to obtain real-time imaging that may facilitate improved surgical decision-making. A study by Ehlers and colleagues [16] in 2014 reported the results of iOCT use on a cohort of 518 eye cases over 24 months, showing that iOCT informed surgical decision-making in 63 of the 146 EPM peeling procedures (43%). No adverse events were reported with the use of iOCT, and the median time that surgery was paused to perform iOCT was 4.9 minutes per scan session. Another study by the same investigators on iOCT use during vitrectomy surgery for dense vitreous hemorrhage surgery showed that multiple eyes had structural abnormalities, eg ERMs and macular edema, that were revealed intraoperatively. This finding implies that iOCT has the potential to provide real-time information that may impact surgical management and patient outcomes [17]. With regards to the concurrent use of 27-gauge and iOCT, the literature remains quite sparse. However, a case report from 2015 discussing iOCTassisted 27-gauge MIVS showed that 27-gauge demonstrated minimal shadow casting on the underlying tissues as compared with 25-gauge and 23-gauge, providing excellent intraoperative visualization of retinal tissues [18]. This finding implies that 27-gauge and iOCT may be synergistic developments, each contributing unique but complementary enhancements to the retina surgeon’s repertoire. CHALLENGES Despite the myriad advantages that 27-gauge potentially offers to the techsavvy surgeon, there remain some challenges with the technology that require addressing. Given the reduced inner diameter of the 27-gauge vitrector compared with 25-gauge (0.275 mm vs 0.347 mm, respectively), maintaining sufficient aspiration and infusion rates remains an engineering challenge [7,12]. A cursory analysis of the difference in flow rates can be made using Poiseuille’s law, which shows that decreasing the radius by 21% (ie, 25-gauge to 27-gauge) given constant pressure decreases the volume flow rate by 61% [14]. With that said, the
27-GAUGE VITRECTOMY
133
reduced flow may be partially mitigated by the faster cutting speeds and increased duty cycles of 27-gauge vitrectomy as well as increased driving pressure, although further studies are required to validate this claim [12]. In addition, the relatively short length of currently available probes complicates the use of 27 gauge in highly myopic eyes. SUMMARY The use of smaller-gauge sutureless vitrectomy systems has reduced surgical trauma while maintaining excellent patient outcomes, resulting in better postoperative recovery and improved patient satisfaction. The 27-gauge vitrector is the most recent development in this line of technological innovation and has a similar rigidity to 25-gauge instruments and sufficient cutting and aspiration capabilities. The 2015 Preferences and Trends survey of the American Society of Retina Specialists [19] showed that 23% of US-based surgeons do not anticipate using 27-gauge vitrectomy in the near future. However, 51% of responders reported that they intend to use 27-gauge in 1% to 50% of their cases, and 22.3% said that they intend to use 27-gauge in greater than 50% of their cases. Of the surgeons who use 27-gauge, an overwhelming majority (76% in the United States, 80.6% internationally) prefer the Alcon Constellation vitrectomy system. Current data show that 27-gauge vitrectomies show comparable outcomes and complication rates compared with previous generations of instruments, on top of demonstrating novel applications specific to 27-gauge. Furthermore, the increased precision of tissue manipulation with 27-gauge, along with the development of iOCT, all point toward better outcomes with smaller-gauge vitrectomy in the future. Although a learning curve will be required for the adoption of 27-gauge surgery by the retinal community, it is likely that the transition to 27-gauge surgery will speak for itself if instrumentation, as well as outcomes, continues to demonstrate benefits for patients and surgeons alike. References [1] Machemer R, Buettner H, Norton EW, et al. Vitrectomy: a pars plana approach. Trans Am Acad Ophthalmol Otolaryngol 1971;7:813–20. [2] Chen JC. Sutureless pars plana vitrectomy through self-sealing sclerotomies. Arch Ophthalmol 1996;114(10):1273–5. [3] Fujii GY, De Juan E Jr, Humayun MS, et al. A new 25-gauge instrument system for transconjunctival sutureless vitrectomy surgery. Ophthalmology 2002;109:1807–12. [4] Lakhanpal RR, Humayun MS, de Juan E Jr, et al. Outcomes of 140 consecutive cases of 25-gauge transconjunctival surgery for posterior disease. Ophthalmology 2005;112: 817–24. [5] Eckhardt C. Transconjunctival sutureless 23-gauge vitrectomy. Retina 2005;25:208–11. [6] Kellner L, Wimpissinger B, Stolba U, et al. 25-Gauge vs 20-gauge system for pars plana vitrectomy: a prospective randomised clinical trial. Br J Ophthalmol 2007;91:945–8. [7] Martinez-Toldos JJ, Hoyos JE. Step by step vitrectomy. 2nd edition. New Delhi: Jaypee Brothers Medical Publishers Ltd; 2013. p. 184–201. [8] Khanduja S, Kakkar A, Majumdar S, et al. Small gauge vitrectomy: recent update. Oman J Ophthalmol 2013;6(1):3–11.
134
SHEYMAN, LIN, & LIEBERMAN
[9] Oshima Y, Wakabayashi T, Sato T, et al. A 27-gauge instrument system for transconjunctival sutureless microincision vitrectomy surgery. Ophthalmology 2010;117(1):93–102. [10] Oshima Y, Wakabayashi T, Ohguro N, et al. 27-gauge sharp-tip short-shaft pneumatic vitreous cutter for transconjunctival sutureless vitreous biopsy. Retina 2011;31(2):419–21. [11] Mitsui K, Kogo J, Takeda H, et al. Comparative study of 27-gauge vs 25-gauge vitrectomy for epiretinal membrane. Eye (Lond) 2016. [Epub ahead of print]. [12] Khan MA, Shahlaee A, Toussaint B, et al. Outcomes of 27 gauge microincision vitrectomy surgery for posterior segment disease. Am J Ophthalmol 2016;161:36–43.e2. [13] Yamane S, Inoue M, Arakawa A, et al. Sutureless 27-gauge needle-guided intrascleral intraocular lens implantation with lamellar scleral dissection. Ophthalmology 2014;121(1): 61–6. [14] Garg SJ, Fineman MS. Do faster cutting speeds really make a difference? American Society of Retina Specialists; 2015. Accessed January 9, 2016. [15] Dugel PU, Abulon DJ, Dimalanta R. Comparison of attraction capabilities associated with high-speed, dual-pneumatic vitrectomy probes. Retina 2015;35(5):915–20. [16] Ehlers JP, Dupps WJ, Kaiser PK, et al. The Prospective Intraoperative and Perioperative Ophthalmic ImagiNg with Optical CoherEncE TomogRaphy (PIONEER) study: 2-year results. Am J Ophthalmol 2014;158(5):999–1007. [17] Ehlers JP, Griffith JF, Srivastava SK. Intraoperative optical coherence tomography during vitreoretinal surgery for dense vitreous hemorrhage in the pioneer study. Retina 2015;35(12): 2537–42. [18] Kunikata H, Nakazawa T. Intraoperative optical coherence tomography-assisted 27-gauge vitrectomy in eyes with vitreoretinal diseases. Case Rep Ophthalmol 2015;6(2):216–22. [19] American Society of Retina Specialist Annual Preferences and Trends Survey. 2015.