- Email: [email protected]
Intraoperative Breakage of 20-Gauge Tano Forceps
FIGURE. (Left) Fundus photographs of a rhesus monkey retina 1 week after photodynamic therapy (PDT). Despite the laser being set to irradiate a spot of 5000 m, the actual spot size was only 3900 m. (Right) Fundus photograph of rhesus monkey retina 1 week after PDT, after the correction of the laser diameter (5000 m).
TABLE. Changes in Spot Size of Photodynamic Therapy in Three Rhesus Monkeys Monkey 1
spot size setting (A) actual spot size (B) relative size of actual spot (B/A) relative area of actual spot (B2/A2) relative energy/area of actual spot (A2/B2)
Monkey 2
Monkey 3
Average
5000 m 4000 m 3000 m 3900 m 3000 m 2300 m 0.78
0.75
0.77
0.77
0.61
0.56
0.59
0.59
1.64
1.78
1.70
1.71
These values are in agreement with the previous data that were obtained with a model eye.4 In the fourth monkey, the magnification factor was changed from 1.82 to 1.40 (1.82 ⫻ 0.77), based on the results from the other three monkeys (Table). One week after PDT, we noted that the size of PDT spot was larger and that the retinal color change was milder (Figure, right). These results show in the in vivo demonstration that the diameter of PDT laser spot is smaller for eyes with shorter axial lengths when an indirect laser lens (magnification factor, ⬎1.0) is used. The results also suggest that, when PDT is performed on patients with shorter axial lengths, the effects of PDT will be stronger. Although we have not performed PDT on patients with very short axial lengths, a reduction of the spot diameter should be considered for such cases.4 REFERENCES
1. Photodynamic therapy of subfoveal choroidal neovascularization in age-related macular degeneration with verteporfin:
VOL. 141, NO. 1
one-year results of 2 randomized clinical trials-TAP report: treatment of age-related macular degeneration with photodynamic therapy (TAP) Study Group. Arch Ophthalmol 1999; 117:1329 –1345. 2. Verteporfin in Photodynamic Therapy Study Group. Photodynamic therapy of subfoveal choroidal neovascularization in pathologic myopia with verteporfin. 1-year results of a randomized clinical trial-VIP report no. 1. Ophthalmology 2001; 108:841– 852. 3. Mainster MA, Crossman JL, Erickson PJ, Heacock GL. Retinal laser lenses: magnification, spot size, and field of view. Br J Ophthalmol 1990;74:177–179. 4. Stur M, Ansari-Shahrezaei S. The effect of axial length on laser spot size and laser irradiance. Arch Ophthalmol 2001;119:1323–1328.
Intraoperative Breakage of 20-Gauge Tano Forceps Karl U. Bartz-Schmidt, MD, Ihab El-Araj, MD, Faik Gelisken, MD, Eva Reinthal, MD, Focke Ziemssen, MD, Nicole Eter, MD, Frank G. Holz, MD, and Salvatore Grisanti, MD
Accepted for publication Aug 1, 2005. From the Department of Ophthalmology I, Division of Vitreoretinal Surgery, Eberhard-Karls University of Tuebingen, Tuebingen, Germany (K.U.B.-S., H.El-A., F.G., E.R., F.Z., S.G.); and the Department of Ophthalmology, University of Bonn, Bonn, Germany (N.E., F.H.). Inquiries to Salvatore Grisanti, MD, Department of Ophthalmology I, Division of Vitreoretinal Surgery, Eberhard-Karls University of Tuebingen, Schleichstrasse 12-16, 72076 Tuebingen, Germany; fax: ⫹⫹49 7071 295215; e-mail: [email protected]
BRIEF REPORTS
215
FIGURE 1. Intraoperative photographs of cases 1 (Left) and 2 (Right) that disclose one branch/tip of the Tano forceps that is lodged on the posterior pole.
PURPOSE: To report three cases with breakage of a 20-gauge kryptonite forceps during vitreoretinal surgery. DESIGN: Interventional case report. METHODS: Pars plana vitrectomy that included a membrane peeling was performed in three patients through standard ports with 20-gauge vitrectomy systems. The peeling procedure was attempted with the end-gripping kryptonite forceps. RESULTS: Intraoperatively, the branch/tip broke and dropped onto the posterior pole. Removal of the broken part was uncomplicated, and the subsequent clinical course was unremarkable. In one case, the handle and branch/tip part were exchanged inadvertently. In the other two cases, neither an exchange nor a maladaptation of the parts was noted. CONCLUSION: An exchange of the hand piece and gripping end may increase the risk of breakage and retinal damage. The delicate gripping tips, however, may break because of inadequate maintenance and/or aging of the material. Intraoperative visual and functional examination is recommended before intraocular use. (Am J Ophthalmol 2006;141:215–217. © 2006 by Elsevier Inc. All rights reserved.)
E
caused no obvious retinal damage. The tip was removed, and the procedure was completed as planned. ● CASE 2:
At the Department of Ophthalmology, University of Bonn, a 64-year-old woman underwent vitrectomy with membrane peeling for macular pucker. Intraoperatively, the tip broke and fell on the retina (Figure 1 (Right)). The instrument was collected by Synergetics Inc, identified to be a Tano 39.23 S forceps, and shipped immediately to their laboratories in St. Charles, Missouri, for a complete investigation.
● CASE 3:
The third case was reported by the company itself. A loaned Tano 39.23 forceps had been serviced to a German eye hospital to replace another instrument. During routine surgery on actuation, a branch broke off the instrument while it was inside the patient’s eye. In case 1, examination disclosed an accidental exchange of instrument parts during reprocessing. This exchange most probably was responsible for the dysfunction and breakage. As shown in cases 2 and 3, however, a breakage may also occur in accurately fitted instruments. To reduce the risk of iatrogenic infection with transmissible spongiform encephalopathies,1 Germany, like other countries, has introduced new disinfection and sterilization guidelines. These include validated machine wash cycles with alkaline solutions and steam sterilization at 134°C.2,3 Size and geometry of some microsurgical instruments pose a problem within the reprocessing. To enable a more effective cleaning and sterilization, Synergetics Inc instruments are built of two components: a handle and a shaft. Similar, but not identical parts, of different instruments, however, implicate the risk of being exchanged as in the first case: the shaft of the 39.23 forceps was joined falsely to a 39.24 handle (Figure 2), which is designed for the
ND-GRIPPING FORCEPS ARE USED COMMONLY DURING
vitreoretinal surgery. We report on intraocular breakage of the tip using a kryptonite forceps (Tano 39.23; Synergetics Inc, St. Charles, Missouri, USA). This is a 20-gauge instrument shaft with a 25-gauge tip.
● CASE 1:
At the Department of Ophthalmology, University of Tuebingen, a 64-year-old man underwent vitrectomy for silicone oil removal and epiretinal membrane peeling. The peeling was attempted with a Tano 39.23 20-gauge forceps. During this maneuver, the tip broke and dropped onto the posterior pole (Figure 1 (Left)) but
216
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OF
OPHTHALMOLOGY
JANUARY 2006
FIGURE 2. Photograph shows the handle of a 39.24 forceps that is connected to the shaft of a 39.23 Tano forceps.
FIGURE 3. Scanning electron microphotograph shows the broken branch/tip of a 39.24 forceps from case 2.
20-gauge (shaft) version of the intraocular forceps. Because each individual instrument incorporates different stroke requirements, the handles of the instruments are calibrated to the tips and must not be switched for obvious reasons. Excessive mechanical force applied to the shaft because of the incorrect handle configuration may have caused the first accident. On recommendation to mark the related handles and shafts, Synergetics Inc has now etched all instruments with a unique identification serial number on both parts to ensure correct configuration and proper assembly. Inaccurate fit of the instruments, however, was excluded in cases 2 and 3. Synergetics Inc laboratories received and inspected the instrument from Bonn and reported that this instrument may have been damaged at the tip. They presumed that the damage derived from a previous bump against a harder surface that caused a crack at the shaft and that it may have been present for some time before instrument failure. Poor instrument maintenance was also VOL. 141, NO. 1
assumed to be the reason in case 3. Scanning electron microscopy of the forceps in Bonn revealed changes of the outer and inner surface of the material (Figure 3) that are suggestive for aging of the material rather than accidental damage. It is unclear whether these alterations and finally the breakage of the instruments are caused by the new reprocessing procedures that include validated machine wash cycles with alkaline solutions. In Germany, the company has sold approximately 200 Tano forceps in 20and 25-gauge and more than 5000 forceps worldwide (personal communication from a representative of Synergetics Inc). We are unaware of similar instrument failures in other European countries that have similar guidelines to those in Germany. Two ongoing projects in Germany are analyzing the effect of the new reprocessing procedures on instruments and materials. In summary, a proper maintenance and assembly of microsurgical instruments is prudent. Additionally, a visual and functional examination of these instruments under the microscope is recommended before intraocular use. REFERENCES
1. Rutala W, Weber DJ. Creutzfeld-Jacob. Disease: recommendations for disinfection and sterilization. Healthcare Epidemiol 1995;39:367–374. 2. Kommission für Krankenhaushygiene und Infektionsprävention beim Robert Koch-Institut und des Bundesinstituts für Arzneimittel und Medizinprodukte. Anforderungen der Hygiene bei der Aufbereitung von Medizinprodukten. Bundesgesundheitsbl - Gesundheitsforsch - Gesundheitsschutz 2001;44:1115–1126. 3. Task Force vCJK am Robert Koch-Institut (RKI). Die Variante der Creutzfeldt-Jakob-Krankheit (vCJK). Epidemiologie, Erkennung, Diagnostik und Prävention unter besonderer ¨ bertragung durch MedizBerücksichtigung einer iatrogenen U inprodukte, insbesondere chirurgische Instrumente. Bundesgesundheitsbl - Gesundheitsforsch - Gesundheitsschutz 2002; 45:376 –394.
BRIEF REPORTS
217
TABLE. Changes in Spot Size of Photodynamic Therapy in Three Rhesus Monkeys Monkey 1
spot size setting (A) actual spot size (B) relative size of actual spot (B/A) relative area of actual spot (B2/A2) relative energy/area of actual spot (A2/B2)
Monkey 2
Monkey 3
Average
5000 m 4000 m 3000 m 3900 m 3000 m 2300 m 0.78
0.75
0.77
0.77
0.61
0.56
0.59
0.59
1.64
1.78
1.70
1.71
These values are in agreement with the previous data that were obtained with a model eye.4 In the fourth monkey, the magnification factor was changed from 1.82 to 1.40 (1.82 ⫻ 0.77), based on the results from the other three monkeys (Table). One week after PDT, we noted that the size of PDT spot was larger and that the retinal color change was milder (Figure, right). These results show in the in vivo demonstration that the diameter of PDT laser spot is smaller for eyes with shorter axial lengths when an indirect laser lens (magnification factor, ⬎1.0) is used. The results also suggest that, when PDT is performed on patients with shorter axial lengths, the effects of PDT will be stronger. Although we have not performed PDT on patients with very short axial lengths, a reduction of the spot diameter should be considered for such cases.4 REFERENCES
1. Photodynamic therapy of subfoveal choroidal neovascularization in age-related macular degeneration with verteporfin:
VOL. 141, NO. 1
one-year results of 2 randomized clinical trials-TAP report: treatment of age-related macular degeneration with photodynamic therapy (TAP) Study Group. Arch Ophthalmol 1999; 117:1329 –1345. 2. Verteporfin in Photodynamic Therapy Study Group. Photodynamic therapy of subfoveal choroidal neovascularization in pathologic myopia with verteporfin. 1-year results of a randomized clinical trial-VIP report no. 1. Ophthalmology 2001; 108:841– 852. 3. Mainster MA, Crossman JL, Erickson PJ, Heacock GL. Retinal laser lenses: magnification, spot size, and field of view. Br J Ophthalmol 1990;74:177–179. 4. Stur M, Ansari-Shahrezaei S. The effect of axial length on laser spot size and laser irradiance. Arch Ophthalmol 2001;119:1323–1328.
Intraoperative Breakage of 20-Gauge Tano Forceps Karl U. Bartz-Schmidt, MD, Ihab El-Araj, MD, Faik Gelisken, MD, Eva Reinthal, MD, Focke Ziemssen, MD, Nicole Eter, MD, Frank G. Holz, MD, and Salvatore Grisanti, MD
Accepted for publication Aug 1, 2005. From the Department of Ophthalmology I, Division of Vitreoretinal Surgery, Eberhard-Karls University of Tuebingen, Tuebingen, Germany (K.U.B.-S., H.El-A., F.G., E.R., F.Z., S.G.); and the Department of Ophthalmology, University of Bonn, Bonn, Germany (N.E., F.H.). Inquiries to Salvatore Grisanti, MD, Department of Ophthalmology I, Division of Vitreoretinal Surgery, Eberhard-Karls University of Tuebingen, Schleichstrasse 12-16, 72076 Tuebingen, Germany; fax: ⫹⫹49 7071 295215; e-mail: [email protected]
BRIEF REPORTS
215
FIGURE 1. Intraoperative photographs of cases 1 (Left) and 2 (Right) that disclose one branch/tip of the Tano forceps that is lodged on the posterior pole.
PURPOSE: To report three cases with breakage of a 20-gauge kryptonite forceps during vitreoretinal surgery. DESIGN: Interventional case report. METHODS: Pars plana vitrectomy that included a membrane peeling was performed in three patients through standard ports with 20-gauge vitrectomy systems. The peeling procedure was attempted with the end-gripping kryptonite forceps. RESULTS: Intraoperatively, the branch/tip broke and dropped onto the posterior pole. Removal of the broken part was uncomplicated, and the subsequent clinical course was unremarkable. In one case, the handle and branch/tip part were exchanged inadvertently. In the other two cases, neither an exchange nor a maladaptation of the parts was noted. CONCLUSION: An exchange of the hand piece and gripping end may increase the risk of breakage and retinal damage. The delicate gripping tips, however, may break because of inadequate maintenance and/or aging of the material. Intraoperative visual and functional examination is recommended before intraocular use. (Am J Ophthalmol 2006;141:215–217. © 2006 by Elsevier Inc. All rights reserved.)
E
caused no obvious retinal damage. The tip was removed, and the procedure was completed as planned. ● CASE 2:
At the Department of Ophthalmology, University of Bonn, a 64-year-old woman underwent vitrectomy with membrane peeling for macular pucker. Intraoperatively, the tip broke and fell on the retina (Figure 1 (Right)). The instrument was collected by Synergetics Inc, identified to be a Tano 39.23 S forceps, and shipped immediately to their laboratories in St. Charles, Missouri, for a complete investigation.
● CASE 3:
The third case was reported by the company itself. A loaned Tano 39.23 forceps had been serviced to a German eye hospital to replace another instrument. During routine surgery on actuation, a branch broke off the instrument while it was inside the patient’s eye. In case 1, examination disclosed an accidental exchange of instrument parts during reprocessing. This exchange most probably was responsible for the dysfunction and breakage. As shown in cases 2 and 3, however, a breakage may also occur in accurately fitted instruments. To reduce the risk of iatrogenic infection with transmissible spongiform encephalopathies,1 Germany, like other countries, has introduced new disinfection and sterilization guidelines. These include validated machine wash cycles with alkaline solutions and steam sterilization at 134°C.2,3 Size and geometry of some microsurgical instruments pose a problem within the reprocessing. To enable a more effective cleaning and sterilization, Synergetics Inc instruments are built of two components: a handle and a shaft. Similar, but not identical parts, of different instruments, however, implicate the risk of being exchanged as in the first case: the shaft of the 39.23 forceps was joined falsely to a 39.24 handle (Figure 2), which is designed for the
ND-GRIPPING FORCEPS ARE USED COMMONLY DURING
vitreoretinal surgery. We report on intraocular breakage of the tip using a kryptonite forceps (Tano 39.23; Synergetics Inc, St. Charles, Missouri, USA). This is a 20-gauge instrument shaft with a 25-gauge tip.
● CASE 1:
At the Department of Ophthalmology, University of Tuebingen, a 64-year-old man underwent vitrectomy for silicone oil removal and epiretinal membrane peeling. The peeling was attempted with a Tano 39.23 20-gauge forceps. During this maneuver, the tip broke and dropped onto the posterior pole (Figure 1 (Left)) but
216
AMERICAN JOURNAL
OF
OPHTHALMOLOGY
JANUARY 2006
FIGURE 2. Photograph shows the handle of a 39.24 forceps that is connected to the shaft of a 39.23 Tano forceps.
FIGURE 3. Scanning electron microphotograph shows the broken branch/tip of a 39.24 forceps from case 2.
20-gauge (shaft) version of the intraocular forceps. Because each individual instrument incorporates different stroke requirements, the handles of the instruments are calibrated to the tips and must not be switched for obvious reasons. Excessive mechanical force applied to the shaft because of the incorrect handle configuration may have caused the first accident. On recommendation to mark the related handles and shafts, Synergetics Inc has now etched all instruments with a unique identification serial number on both parts to ensure correct configuration and proper assembly. Inaccurate fit of the instruments, however, was excluded in cases 2 and 3. Synergetics Inc laboratories received and inspected the instrument from Bonn and reported that this instrument may have been damaged at the tip. They presumed that the damage derived from a previous bump against a harder surface that caused a crack at the shaft and that it may have been present for some time before instrument failure. Poor instrument maintenance was also VOL. 141, NO. 1
assumed to be the reason in case 3. Scanning electron microscopy of the forceps in Bonn revealed changes of the outer and inner surface of the material (Figure 3) that are suggestive for aging of the material rather than accidental damage. It is unclear whether these alterations and finally the breakage of the instruments are caused by the new reprocessing procedures that include validated machine wash cycles with alkaline solutions. In Germany, the company has sold approximately 200 Tano forceps in 20and 25-gauge and more than 5000 forceps worldwide (personal communication from a representative of Synergetics Inc). We are unaware of similar instrument failures in other European countries that have similar guidelines to those in Germany. Two ongoing projects in Germany are analyzing the effect of the new reprocessing procedures on instruments and materials. In summary, a proper maintenance and assembly of microsurgical instruments is prudent. Additionally, a visual and functional examination of these instruments under the microscope is recommended before intraocular use. REFERENCES
1. Rutala W, Weber DJ. Creutzfeld-Jacob. Disease: recommendations for disinfection and sterilization. Healthcare Epidemiol 1995;39:367–374. 2. Kommission für Krankenhaushygiene und Infektionsprävention beim Robert Koch-Institut und des Bundesinstituts für Arzneimittel und Medizinprodukte. Anforderungen der Hygiene bei der Aufbereitung von Medizinprodukten. Bundesgesundheitsbl - Gesundheitsforsch - Gesundheitsschutz 2001;44:1115–1126. 3. Task Force vCJK am Robert Koch-Institut (RKI). Die Variante der Creutzfeldt-Jakob-Krankheit (vCJK). Epidemiologie, Erkennung, Diagnostik und Prävention unter besonderer ¨ bertragung durch MedizBerücksichtigung einer iatrogenen U inprodukte, insbesondere chirurgische Instrumente. Bundesgesundheitsbl - Gesundheitsforsch - Gesundheitsschutz 2002; 45:376 –394.
BRIEF REPORTS
217