ajog.org
Letters to the Editors 4. Tixier H, Thouvenot S, Coulange L, et al. Cesarean section in morbidly obese women: supra or subumbilical transverse incision? Acta Obstet Gynecol 2009;88:1049-52.
ª 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.ajog. 2014.07.010
REPLY We appreciate Drs Gordon and Welch’s interest in our study. They reflect on the potential benefits of the “Sokol” incision in which the transverse skin incision is located in the supraumbilical area to avoid the abdominal pannus. Unfortunately, the Maternal-Fetal Medicine Unit Network cesarean delivery registry did not include the exact location of the transverse skin incision on the maternal abdomen, so we could not assess this clinical question.
It is plausible that the potential benefit of a transverse skin incision (compared with vertical) may be offset by a surgical incision that is located underneath the pannus, with a higher potential for infection. In addition, maternal body mass index and habitus do not always correlate; 2 women with the same body mass index may have substantially different abdominal fat distribution and may benefit from different incision locations. We agree that these questions should be tested in a randomized clinical trial. Caroline C. Marrs, MD Sean C. Blackwell, MD Department of Obstetrics and Gynecology University of Texas Health Science Center at Houston-Children’s Memorial Hermann Hospital Houston, TX The authors report no conflict of interest. ª 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.ajog. 2014.07.011
Re: The debate over robotics in benign gynecology TO THE EDITORS: I read the outstanding article of Dr Rardin1 on robotics and the challenges facing minimally invasive surgery programs with interest. I have 2 comments regarding a statement in his abstract: “.the best currently available science suggests that, in the hands of experts, robotics offers little in surgical advantage over laparoscopy, at increased expense..” The 3 randomized controlled trials cited in support of this statement all found longer operative times, the largest driver of cost, with robotics. Since each study compared robotic and laparoscopic surgeries performed by expert laparoscopists who had relatively little robotic experience (10-30 robotic cases), all 3 authors, I believe, made the assumption that experienced laparoscopists can transition to robotics with a short learning curve. There is evidence that this assumption is incorrect. For example, Payne and Dauterive2 found that robotic operative times for 2 experienced laparoscopic surgeons continued to decrease through the first 75 robotic cases, and then plateaued at 16% shorter than laparoscopic procedures (79 vs 92 minutes). Woelk et al3 analyzed 566 robotic hysterectomies performed over a 36-month period at the Mayo Clinic, and estimated the learning curve to be 91 cases. Thus, the “best currently available science” on this subject may be flawed by invalid assumptions regarding the learning curve for robotic surgery, even “in the hands of experts.” Second, intraoperative conversion rates to laparotomy appear to be lower with robotics. Payne and Dauterive2 compared their last 100 laparoscopic to their first 100 robotic hysterectomies, and found a significantly lower (4% vs 9%) intraoperative conversion rate for robotics. In particular, intraoperative conversion because of pelvic adhesive disease was less likely with robotics (0 vs 8 patients). Patzkowsky et al4 compared outcomes for 3 experienced laparoscopic surgeons 710 American Journal of Obstetrics & Gynecology DECEMBER 2014
performing laparoscopic and robotic hysterectomies for benign disease over a 9-year period at the University of Michigan (288 laparoscopic, 255 robotic), and found fewer conversions (1.7% vs 6.2%, P ¼ .007) and reoperations (1.7% vs 5.1%, P ¼ .03) in the robotics group, despite a higher incidence of previous laparotomies (78.4% vs 49.8%, P ¼ .002), stage III/IV endometriosis (15.3% vs 4.7%, P ¼ .001), and severe adhesions (23.3% vs 13.2%, P ¼ .003) in that group. Our patients care deeply about our ability to deliver the minimally invasive procedures we recommend to them. If robotics increases our probability of success, with a better ability to deal with complex pelvic pathology and a lower likelihood of intraoperative conversion to laparotomy, I believe this is the strongest argument for robotics over traditional laparoscopy in benign gynecology. W. Scott Walker, MD Department of Obstetrics and Gynecology Alpert School of Medicine, Brown University Providence, RI [email protected] W.S.W. serves as a proctor and case observation site (2011 through 2014) and served on the speakers’ bureau (2011 through 2013) for Intuitive Surgical Inc.
REFERENCES 1. Rardin CR. The debate over robotics in benign gynecology. Am J Obstet Gynecol 2014;210:418-22. 2. Payne TN, Dauterive FR. A comparison of total laparoscopic hysterectomy to robotically assisted hysterectomy: surgical outcomes in a community practice. J Minim Invasive Gynecol 2008;15:286-91. 3. Woelk JL, Casiano ER, Weaver AL, Gostout BS, Trabuco EC, Gebhart JB. The learning curve of robotic hysterectomy. Obstet Gynecol 2013;121:87-95.
ajog.org 4. Patzkowsky KE, As-Sanie S, Smorgick N, Song AH, Advincula AP. Perioperative outcomes of robotic versus laparoscopic hysterectomy for benign disease. JSLS 2013;17:100-6. ª 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.ajog. 2014.07.013
REPLY Dr Walker’s comments are representative of some of the important features of the more global conversation among surgeons and administrators of robotics programs (proponents and naysayers alike). Surgical trials are often plagued by the issue that participating surgeons have different experience levels for different techniques. Thus, Dr Walker’s critique of the available randomized controlled trials in robotic gynecologic surgery is valid, in that the surgeons’ experience with laparoscopy was overall more extensive than with robotic surgery. However, the methodological quality of a welldesigned randomized controlled trial is generally better at controlling confounders than retrospective cohort designs using historical controls. The conversation around the extent of the learning curve for robotics has been a difficult one. Why robotic surgery should demonstrate a more prolonged learning curve than many other procedures in gynecology, especially when many surgeons are coming to robotic surgery as experienced endoscopic surgeons, has not been well studied. Certainly part of the answer lies in the fact that the entire surgical team must learn a new set of tasks with robotic surgery; the operating room team, not just the expertise of the surgeon, will contribute to the efficiency of the case. Still, the acknowledgment of the extent of the robotic learning curve poses a challenge to surgeons and systems alike; should surgeons inform each of their first 70-100 patients that they are “on the learning curve” and, therefore, may have longer operative times and potentially adverse events associated with this? It is my hope that educational
Letters to the Editors efforts, notably simulation programs for skills acquisition and maintenance, can shorten the learning curve. A growing number of published trials have provided support to the role that simulation might play in new technologies such as robotic surgery, where an extended learning curve has been observed.1,2 The intent of my message was not to malign robotic surgery, but rather to support all forms of minimally invasive surgery, and to promote efforts to define a set of circumstances in which a robotic approach might be better suited to positive outcomes than others. These assessments should be carried out at local as well as academic levels. I would echo the following statement by the Society of Gynecologic Surgeons’ Systematic Review Group, which concluded, “Conflicting data are obtained when comparing robotics vs laparoscopic techniques. Therefore, the specific method of minimally invasive surgery, whether conventional laparoscopy or robotic surgery, should be tailored to patient selection, surgeon ability, and equipment availability.”3 Charles R. Rardin, MD Women and Infant’s Hospital Warren Alpert Medical School of Brown University Providence, RI [email protected] The author reports no conflict of interest.
REFERENCES 1. Abboudi H, Khan MS, Aboumarzouk O, et al. Current status of validation for robotic surgery simulatorsea systematic review. BJU Int 2012;111:194-205. 2. Culligan P, Gurshumov E, Lewis C, et al. Predictive validity of a training protocol using a robotic surgery simulator. Female Pelvic Med Reconstr Surg 2014;20:48-51. 3. Gala RB, Margulies R, Steinberg A, et al. Systematic review of robotic surgery in gynecology: robotic techniques compared with laparoscopy and laparotomy. J Minim Invasive Gynecol 2014;21:353-61. ª 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.ajog. 2014.07.014
Noninvasive prenatal screening for fetal trisomies 21, 18, 13 and the common sex chromosome aneuploidies from maternal blood using massively parallel genomic sequencing of DNA TO THE EDITORS: We read with interest the study by Porreco et al1 on noninvasive prenatal screening (NIPS) of common aneuploidies by massively parallel sequencing of cell-free DNA that is derived from placental trophoblasts. The NIPS results were compared with cytogenetic findings that
were obtained from karyotyping of chorionic villi or amniotic fluid samples. For trisomy 21 (T21), there were 3 false-positive (FP) and no false-negative (FN) cases; for trisomy 18 (T18) and 13 (T13), there were 3 and 2 FN cases, respectively, and no FP cases. The DECEMBER 2014 American Journal of Obstetrics & Gynecology
711
Letters to the Editors 4. Tixier H, Thouvenot S, Coulange L, et al. Cesarean section in morbidly obese women: supra or subumbilical transverse incision? Acta Obstet Gynecol 2009;88:1049-52.
ª 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.ajog. 2014.07.010
REPLY We appreciate Drs Gordon and Welch’s interest in our study. They reflect on the potential benefits of the “Sokol” incision in which the transverse skin incision is located in the supraumbilical area to avoid the abdominal pannus. Unfortunately, the Maternal-Fetal Medicine Unit Network cesarean delivery registry did not include the exact location of the transverse skin incision on the maternal abdomen, so we could not assess this clinical question.
It is plausible that the potential benefit of a transverse skin incision (compared with vertical) may be offset by a surgical incision that is located underneath the pannus, with a higher potential for infection. In addition, maternal body mass index and habitus do not always correlate; 2 women with the same body mass index may have substantially different abdominal fat distribution and may benefit from different incision locations. We agree that these questions should be tested in a randomized clinical trial. Caroline C. Marrs, MD Sean C. Blackwell, MD Department of Obstetrics and Gynecology University of Texas Health Science Center at Houston-Children’s Memorial Hermann Hospital Houston, TX The authors report no conflict of interest. ª 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.ajog. 2014.07.011
Re: The debate over robotics in benign gynecology TO THE EDITORS: I read the outstanding article of Dr Rardin1 on robotics and the challenges facing minimally invasive surgery programs with interest. I have 2 comments regarding a statement in his abstract: “.the best currently available science suggests that, in the hands of experts, robotics offers little in surgical advantage over laparoscopy, at increased expense..” The 3 randomized controlled trials cited in support of this statement all found longer operative times, the largest driver of cost, with robotics. Since each study compared robotic and laparoscopic surgeries performed by expert laparoscopists who had relatively little robotic experience (10-30 robotic cases), all 3 authors, I believe, made the assumption that experienced laparoscopists can transition to robotics with a short learning curve. There is evidence that this assumption is incorrect. For example, Payne and Dauterive2 found that robotic operative times for 2 experienced laparoscopic surgeons continued to decrease through the first 75 robotic cases, and then plateaued at 16% shorter than laparoscopic procedures (79 vs 92 minutes). Woelk et al3 analyzed 566 robotic hysterectomies performed over a 36-month period at the Mayo Clinic, and estimated the learning curve to be 91 cases. Thus, the “best currently available science” on this subject may be flawed by invalid assumptions regarding the learning curve for robotic surgery, even “in the hands of experts.” Second, intraoperative conversion rates to laparotomy appear to be lower with robotics. Payne and Dauterive2 compared their last 100 laparoscopic to their first 100 robotic hysterectomies, and found a significantly lower (4% vs 9%) intraoperative conversion rate for robotics. In particular, intraoperative conversion because of pelvic adhesive disease was less likely with robotics (0 vs 8 patients). Patzkowsky et al4 compared outcomes for 3 experienced laparoscopic surgeons 710 American Journal of Obstetrics & Gynecology DECEMBER 2014
performing laparoscopic and robotic hysterectomies for benign disease over a 9-year period at the University of Michigan (288 laparoscopic, 255 robotic), and found fewer conversions (1.7% vs 6.2%, P ¼ .007) and reoperations (1.7% vs 5.1%, P ¼ .03) in the robotics group, despite a higher incidence of previous laparotomies (78.4% vs 49.8%, P ¼ .002), stage III/IV endometriosis (15.3% vs 4.7%, P ¼ .001), and severe adhesions (23.3% vs 13.2%, P ¼ .003) in that group. Our patients care deeply about our ability to deliver the minimally invasive procedures we recommend to them. If robotics increases our probability of success, with a better ability to deal with complex pelvic pathology and a lower likelihood of intraoperative conversion to laparotomy, I believe this is the strongest argument for robotics over traditional laparoscopy in benign gynecology. W. Scott Walker, MD Department of Obstetrics and Gynecology Alpert School of Medicine, Brown University Providence, RI [email protected] W.S.W. serves as a proctor and case observation site (2011 through 2014) and served on the speakers’ bureau (2011 through 2013) for Intuitive Surgical Inc.
REFERENCES 1. Rardin CR. The debate over robotics in benign gynecology. Am J Obstet Gynecol 2014;210:418-22. 2. Payne TN, Dauterive FR. A comparison of total laparoscopic hysterectomy to robotically assisted hysterectomy: surgical outcomes in a community practice. J Minim Invasive Gynecol 2008;15:286-91. 3. Woelk JL, Casiano ER, Weaver AL, Gostout BS, Trabuco EC, Gebhart JB. The learning curve of robotic hysterectomy. Obstet Gynecol 2013;121:87-95.
ajog.org 4. Patzkowsky KE, As-Sanie S, Smorgick N, Song AH, Advincula AP. Perioperative outcomes of robotic versus laparoscopic hysterectomy for benign disease. JSLS 2013;17:100-6. ª 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.ajog. 2014.07.013
REPLY Dr Walker’s comments are representative of some of the important features of the more global conversation among surgeons and administrators of robotics programs (proponents and naysayers alike). Surgical trials are often plagued by the issue that participating surgeons have different experience levels for different techniques. Thus, Dr Walker’s critique of the available randomized controlled trials in robotic gynecologic surgery is valid, in that the surgeons’ experience with laparoscopy was overall more extensive than with robotic surgery. However, the methodological quality of a welldesigned randomized controlled trial is generally better at controlling confounders than retrospective cohort designs using historical controls. The conversation around the extent of the learning curve for robotics has been a difficult one. Why robotic surgery should demonstrate a more prolonged learning curve than many other procedures in gynecology, especially when many surgeons are coming to robotic surgery as experienced endoscopic surgeons, has not been well studied. Certainly part of the answer lies in the fact that the entire surgical team must learn a new set of tasks with robotic surgery; the operating room team, not just the expertise of the surgeon, will contribute to the efficiency of the case. Still, the acknowledgment of the extent of the robotic learning curve poses a challenge to surgeons and systems alike; should surgeons inform each of their first 70-100 patients that they are “on the learning curve” and, therefore, may have longer operative times and potentially adverse events associated with this? It is my hope that educational
Letters to the Editors efforts, notably simulation programs for skills acquisition and maintenance, can shorten the learning curve. A growing number of published trials have provided support to the role that simulation might play in new technologies such as robotic surgery, where an extended learning curve has been observed.1,2 The intent of my message was not to malign robotic surgery, but rather to support all forms of minimally invasive surgery, and to promote efforts to define a set of circumstances in which a robotic approach might be better suited to positive outcomes than others. These assessments should be carried out at local as well as academic levels. I would echo the following statement by the Society of Gynecologic Surgeons’ Systematic Review Group, which concluded, “Conflicting data are obtained when comparing robotics vs laparoscopic techniques. Therefore, the specific method of minimally invasive surgery, whether conventional laparoscopy or robotic surgery, should be tailored to patient selection, surgeon ability, and equipment availability.”3 Charles R. Rardin, MD Women and Infant’s Hospital Warren Alpert Medical School of Brown University Providence, RI [email protected] The author reports no conflict of interest.
REFERENCES 1. Abboudi H, Khan MS, Aboumarzouk O, et al. Current status of validation for robotic surgery simulatorsea systematic review. BJU Int 2012;111:194-205. 2. Culligan P, Gurshumov E, Lewis C, et al. Predictive validity of a training protocol using a robotic surgery simulator. Female Pelvic Med Reconstr Surg 2014;20:48-51. 3. Gala RB, Margulies R, Steinberg A, et al. Systematic review of robotic surgery in gynecology: robotic techniques compared with laparoscopy and laparotomy. J Minim Invasive Gynecol 2014;21:353-61. ª 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.ajog. 2014.07.014
Noninvasive prenatal screening for fetal trisomies 21, 18, 13 and the common sex chromosome aneuploidies from maternal blood using massively parallel genomic sequencing of DNA TO THE EDITORS: We read with interest the study by Porreco et al1 on noninvasive prenatal screening (NIPS) of common aneuploidies by massively parallel sequencing of cell-free DNA that is derived from placental trophoblasts. The NIPS results were compared with cytogenetic findings that
were obtained from karyotyping of chorionic villi or amniotic fluid samples. For trisomy 21 (T21), there were 3 false-positive (FP) and no false-negative (FN) cases; for trisomy 18 (T18) and 13 (T13), there were 3 and 2 FN cases, respectively, and no FP cases. The DECEMBER 2014 American Journal of Obstetrics & Gynecology
711
