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‘Isolation bag’ trial renews debate about power morcellation
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A planned clinical trial to evaluate the safety and efficacy of a device designed to catch cancerous tissue in women who undergo power morcellation during laparoscopic hysterectomies has rekindled the debate about the controversial procedure.
The study will assess use of the Olympus PK morcellator and its revamped PneumoLiner tissue containment system in 140 pre- and perimenopausal women aged 35 to 50 years. Olympus America — the manufacturer of both devices — will sponsor the 2-year trial, to be conducted at University of North Carolina at Chapel Hill.
In November 2014, the FDA warned against the use of laparoscopic power morcellators in the majority of women who undergo myomectomy or hysterectomy for treatment of fibroids. The morcellators’ spinning blades can spread undetected uterine sarcomas or other cancers, increasing risks for morbidity and mortality.
“You’re essentially taking tissue and mincing it into smaller pieces in the abdominal cavity,” Jason D. Wright, MD, chief of the division of gynecologic oncology and associate professor of obstetrics and gynecology at Columbia University Medical Center, told HemOnc Today.
“If there is cancer [in the fibroid tissue], there is the potential that you can spread those cancer cells throughout the abdominal cavity,” added Wright, who is not involved in the planned trial. “With morcellation occurring in a bag, theoretically, these cancerous fragments of tissue would not be able to spread.”
Trial under review
The FDA approved the PneumoLiner containment system in April 2016 and the PK Morcellator in November 2016, but the agency indicated heath care providers must share the potential risks of the device with patients. The bag also must include a warning label stating it has not been clinically demonstrated to reduce the risk for spreading cancer.
Hooman Noorchashm, MD, PhD, a cardiac surgeon whose wife, Amy Reed, died of uterine leiomyosarcoma at age 44 years — 4 years after undetected cancer spread during power morcellation — described the planned trial as “unethical and flawed” via a post on the online publishing platform Medium.com.
Noorchashm pointed to the FDA’s acknowledgement that the Pneumoliner containment system has not been proven to reduce the risk for cancer spread during surgery. In addition, gynecological morcellation is “a dangerous violation of a time-tested surgical principle” that resection of tumors with malignant potential always be done in one piece, he wrote.
“It is frankly shocking that an academic institution of UNC’s caliber and its [institutional review board], ethics board and risk managers would ever buy into such flawed and unethical experimentation on women,” he added.
A description of the trial on ClinicalTrials.gov indicates the study is expected to start this month. However, officials at UNC-Chapel Hill are reviewing the concerns Noorchashm raised.
“The university is committed to protecting the rights, safety and welfare of research participants,” Joanne Peters Denny, a UNC-Chapel Hill spokeswoman, told HemOnc Today. “Consistent with this commitment, we take seriously any questions or concerns arising from third parties about our research studies.
“Our institutional review boards are charged with reviewing, approving and overseeing all research studies involving human participants to ensure risks are properly identified and disclosed to research participants,” Peters Danny added. “Our [review board] is currently reviewing the matters Dr. Noorchashm raised. At the conclusion of this review, we will provide further information.”
Stephanie Sherry, executive director of public affairs at Olympus America, told HemOnc Today patient safety is the company’s number one priority.
“Olympus has listened to what doctors, scientists, public health advocates and patients have said about the potential risks associated with power morcellators and their effect on patient safety and health,” Sherry said. “Combined, the PneumoLiner and PK Morcellator provide certain low-risk patients with a minimally invasive, laparoscopic surgical option that avoids open hysterectomy and myomectomy, potentially reducing hospital stays and perioperative complications.”
The primary endpoint of the study is to determine the durability of the PneumoLiner containment system.
Failure will be defined as “disruption of the isolation bag or visible tissue dissemination.” The device will be declared safe if no more than one bag failure is observed in 140 procedures.
Secondary endpoints include ease of use of the PK Morcellator in conjunction with the PneumoLiner bag, intra- or postoperative complications, mean procedure time, estimated blood loss, postoperative pain, hospitalization length and specimen weight.
“When used as directed, the PneumoLiner significantly reduces the risk of disseminating cells and tissue into the peritoneal cavity during power morcellation,” Sherry said. “Because of our commitment to continuing innovation, improvements to our products, and increases in patient safety and service, Olympus frequently conducts additional research, development or studies related to our products, including after they are approved by the FDA or other regulatory bodies around the world. This practice, which is common in the medical device industry, serves the interests of patients and the doctors that use our products.”
‘Data we need’
The FDA estimates approximately one in 352 women who undergo hysterectomy or myomectomy to remove presumed benign fibroids learns she has uterine cancer, and that one in 498 women has an unsuspected leiomyosarcoma.
However, a meta-analysis by Pritts and colleagues — published in 2015 in Journal of Minimally Invasive Gynecology — estimated the prevalence of leiomyosarcoma among women who undergo surgery for presumed benign fibroids at one in 1,960 (0.051%).
Another study by Bojahr and colleagues, published in Archives of Gynecology and Obstetrics, analyzed 8,720 women who had surgery for fibroids, two (0.023%) of whom had leiomyosarcoma.
The percentage of minimally invasive hysterectomies in which power morcellation was used declined significantly after the FDA warning, according to a study by Wright and colleagues.
The rate declined from 13.7% (95% CI, 13.2-14.2) in the fourth quarter of 2013 to 2.8% (95% CI, 2.4-3.1) in the first quarter of 2015 (P < .001).
Wright said he would not deter women from participating in a trial like the one planned at UNC-Chapel Hill.
Most women would prefer a minimally invasive surgery that requires 2 to 4 weeks of recovery instead of an open procedure that requires a longer hospital stay and a 6-week recovery period, he added.
“This is the type of data we need,” Wright said. “We know minimally invasive surgery offers a lot of benefits and we want to be able to offer it to as many women as possible. These types of devices and innovation need to be tested. Theoretically, this should be a safe procedure, morcellating in a bag and trying to limit interabdominal dissemination. But, until this is thoroughly investigated, we won’t know the safety of this.”
It is possible that occult microscopic tumor cells still can escape the bag, Wright added.
“We don’t really know the true incidence of rupture of the bag and spillage of the contents,” he said. “One of the problems with morcellators is that they’ve been diffused in practice without solid scientific evidence, and this is the exact type of study we need to be doing to get this evidence before these devices are used widely in practice.”
The incidence of occult cancer is higher among postmenopausal women who undergo hysterectomies. Consequently, if the Olympus PK morcellator and PneumoLiner system are shown to be effective, oncologists may be more likely to recommend the procedure for premenopausal women who require laparoscopic hysterectomies, Wright said.
“In postmenopausal women, in particular, the risks of the procedure may outweigh the benefits,” he said. “In younger women, the risk for cancer is still quite low. ... In these women, the benefits of being able to have a minimally invasive surgical procedure may outweigh the small risks associated with morcellation. If the bag is found to be a safe technology and there is published data on this, I would think it would start to diffuse into practice again.” – by Chuck Gormley
References:
Bojahr B, et al. Arch Gynecol Obstet. 2015;doi:10.1007/s00404-015-3696-z.
ClinicalTrials.gov. Safety and efficacy of using PK morcellator with Pneumoliner containment hysterectomy. Available at: clinicaltrials.gov/ct2/show/NCT03216772?term=Devices&recrs=abc&cntry1=NA%3AUS&rcv_d=100&show_rss=Y. Accessed on Sept. 5, 2017.
FDA. Immediately in effect guidance document: Product labeling for laparoscopic power morcellators. 2014. Available at www.fda.gov/downloads/medicaldevices/deviceregulationandguidance/guidancedocuments/UCM424123.pdf. Accessed on Sept. 5, 2017.
Noorchashm H. The University of North Carolina’s IRB approves an unethical and flawed clinical trial in women: The power morcellator, risen. Available at: medium.com/@noorchashm/recently-the-university-of-north-carolina-unc-announced-the-start-of-a-very-concerning-clinical-a530ad80889c. Accessed on Sept. 5, 2017.
Pritts E, et al. J Minim Invasive Gynecol. 2015;doi:10.1016/j.jmig.2014.08.781.
Pritts EA, et al. Gynecol Surg. 2015;12:165-177.
Wright JD, et al. JAMA. 2016;doi:10.1001/jama.2016.9432.
For more information:
Joanne Peters Denny can be reached at joanne.peters@unc.edu.
Stephanie Sherry can be reached at stephanie.sherry@olympus.com.
Jason D. Wright, MD, can be reached at jw2459@columbia.edu.
Disclosure: Wright reports no relevant financial disclosures.