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A
Figure 8.5.5. Use of a 30◦hysteroscope lens can help with visualization or placement of the device. (A)Diagramofa30◦scope to help visualize
ostia. By facing the lens of the 30
situation, the device protrudes through the operative channel parallel to the hysteroscope shaft, which may make placement more difficult. (B)
Diagram of the scope turned the other way to help with placement. If the provider is having difficulty with placement of the device, the 30
hysteroscope can be turned to face away from the tubal ostia. This makes visualization of the ostia more difficult and often requires a more
exaggerated angle to obtain visualization of the tubal opening. However, with this position, the delivery device exits the operative channel at an
angle that can make entry into the tubal opening easier. Blue arrow, line of visualization through the 30
Essure delivery device after exiting the hysteroscope operative channel.
◦
hysteroscope toward the ostia, the tubal ostia can be better visualized because of the optics. However, in this
which exits the working channel at 0◦. The 30◦lens may help
if the tubal ostia are at a difficult acute lateral angle. Once both
ostia have been identified, the one that looks easier should be
cannulated first, which will help prevent the endometrium from
becoming edematous and obscuring the tubal ostium while the
more difficult side is being cannulated.
The Essure delivery system is then passed though the introducer and down the working channel of the hysteroscope. With
the tubalostia in view, the Essuredelivery system isadvancedinto
the proximal fallopian tube with constant, gentle forward pressure, which helps prevent tubal spasm. When the black marker
on the delivery catheter is at the ostia, the insert is in the ideal
position spanning the intramural andproximalisthmic segments
of the fallopian tube (Figure 8.5.6A). The micro-insert is now
ready to be deployed. It is important that the handle of the delivery device is stabilized against the hysteroscope during retraction
of the delivery catheter to prevent forward movement and displacement of the micro-insert. To deploy the insert, the thumbwheel on the Essure handle is rotated at one click per second,
retracting the delivery catheter and exposing the wound-down
B
◦
degree hysteroscope; red ball, path of the
counterclockwise until the delivery catheter has visibly disengaged from the micro-insert, and the delivery system is gently
withdrawn from the insert.[7]
Once the delivery system has been withdrawn, the position
of the micro-insert should be examined. Ideally, three to eight
expanded outer coils should be trailing in the endometrial cavity
(Figure 8.5.6C). If there are 18 or more coils seen in the endometrial cavity, the device should be removed; if fewer than 18 coils
are identified in the cavity, the device should be left in place.[7]
The procedure is then repeated on the contralateral side.
Essure placement is a relatively quick procedure to perform.
During the pivotal, phase III trials, the mean hysteroscopy time
was 13 minutes.[5] In this study, the procedure time decreased
rapidly over the first fivecasesperformed by a provider and slowly
thereafter.[5] Since the pivotal trial, other studies have demonstrated even shorter average procedure times, ranging from 8 to
9 minutes.[11,13] In a study done by an independent group in
Spain, the mean time for the procedure was 9 minutes; however,
in the last 35 procedures (out of 85 total), the mean procedure
time decreased to 4 minutes.[13]
micro-insert and its orange attachment to the delivery catheter
(Figure8.5.6B).Approximately 1 cm of the micro-insert’swounddown coils shouldbe visible in the endometrial cavity; toconfirm
proper placement, the small notch in the wound-down insert
should be located just outside the tubal ostium (Figure 8.5.6C).
Once placement isverified, the button on the handle isdepressed,
enabling the thumbwheel to befurther rotated. When the thumbwheel cannotbe rotated any further, the withdrawal of theorange
release catheter is complete, allowing the micro-insert to expand.
Approximately 10 seconds are allowed for the outer coils to fully
expand. With as few rotations as possible, the handle is rotated
Histologic Studies
To evaluate the histologic response to the Essure micro-inserts,
a prehysterectomy study was performed. The Essure microinserts were placed in 33 women who subsequently underwent
a hysterectomy between 24 hours and 12 weeks after device
placement.[9]
The tissue response varied depending on the time elapsed
since device placement. Initially, there was predominantly acute
inflammation, followed by low-level chronic inflammation and
◦
168 — Stephanie N. Morris and Keith Isaacson
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A
C
Figure 8.5.6. Steps for correct placement of the micro-insert. (A) When the black marker on the delivery catheter is at the ostia, the insert is in
the ideal position spanning the intramural and proximal isthmic segments of the fallopian tube. (B) After retracting the delivery catheter and
exposing the wound-down micro-insert, the orange attachment to the delivery catheter can be identified. To confirm proper placement, the small
notch in the wound-down insert should be located just outside the tubal ostium before completing the deployment of the device. (C) Ideally,
three to eight expanded outer coils should be trailing in the endometrial cavity. Here four coils are seen.
fibrosis (Figure8.5.7).[9] The PET fibers elicited a strong fibrotic
and inflammatory tissue response that extended into the space
between the inner and outer coils of the micro-insert. The reaction was localized to the inner portion of the fallopian tube wall
without evidence of fibrosis extending into the wall of the tube,
peritubal adhesions,or serositis. Additionally,there was histologically normal tubal architecture within 5 mm of the distal end of
the micro-insert.[9]
B
tubal occlusion. Bilateral tubal occlusion rates have been reported
to be between 96% and 99% in patients with successful bilateral
placement.[4–6,11]
Failure of placement is often the result of tubal factors leading to increased resistance to advancement of the delivery catheter
and micro-insert. If one micro-insert is placed and the contralateral one cannot be placed, the patient may undergo HSG. If the
tube in which placement failed ispatent,arepeatattemptat placement may beoffered. If thetube is blocked, placement shouldnot
Rate of Bilateral Micro-insert Placement
and Tubal Occlusion
The goal of the Essure procedure is to achieve successful placement of bilateral micro-inserts, which results in bilateral tubal
occlusion. There does not appear to be an obvious relationship
between successful placement of Essure micro-inserts and parity,
obesity, history of prior surgery, mode of prior obstetric delivery
(vaginal delivery or cesarean section), or time in the menstrual
cycle during which the procedure was performed.[5,6] NSAIDs
given before the procedure have been demonstrated to increase
placement success rates.[5] According to one multicenter trial,
placement success rates did not improve substantially in relation
to increased surgeon experience with the device.[5] Depending
on the studycited, successful bilateral placementrates range from
85% to 98%.[4–6,11,13] At 3 months after the procedure, HSG
should be done to confirm correct device location and bilateral
be attempted. If bilateral placement of the micro-inserts cannot
be achieved, the patient is still a candidate for laparoscopic sterilization, or may consider vasectomy for her partner.
In the phase I clinical trial for Essure, 130 women between
the agesof 21and 43 seeking permanent birth control underwent
device placementattempts at a single center.[6] Of thesepatients,
85% had successful placement of both micro-inserts and 3.6%
had the micro-inserts in an unacceptable positionon subsequent
HSG; 98% of women with satisfactory placement of the microinserts had bilateral tubal occlusion demonstrated by HSG at
3 months (Figure 8.5.8).[6] Two women (2%) were found to
have a small leakage past a correctly positioned micro-insert; on
repeat HSG 3 months later, both had complete bilateral tubal
occlusion.[6]
A multicenter phaseII clinical trialrevealed that 200 (88%) of
the 227 women in whom the procedure was attempted had successful placement of bilateral devices.[4] Anatomic reasons, such
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A
Figure 8.5.7. Histologic findings after Essure placement. (A) At 1 week, fibrosis and acute inflammatory cells can be seen infiltrating the device.
(B) Four weeks after placement, both acute and chronic inflammatory cells are present and fibrosis is beginning to occlude the lumen. (C)At10
weeks, dense fibrosis is filling the tubal lumen. Used with permission of Conceptus.
as tortuous variants oftubalanatomy,tubalspasm,occlusion,and
stenosis, accounted for 48% of all placement failures. Procedure
failures, such as the inability to cannulate or advance the catheter
for unknown reasons, and device-related failure accounted for
22% and 19% of all placement failures, respectively. Of the 200
women with successful bilateral deviceplacement,HSG 3 months
after the initial procedure confirmed correct device placement in
191 patients (96%). Bilateral tubal occlusion was noted in 191
women (96%). Of the nine women who had evidence of dye passage past themicro-insert,seven had repeat HSGin3 months that
revealed bilateral tubal occlusion. Two women did not undergo
repeat HSG; one patient expelled the device and the other had
the device placed in the myometrium. Thus, 99% of the women
with correct bilateral placement developed tubal occlusion and
could rely on it for contraception by 6 months after placement.
Four of the women with unsatisfactory device placement asiden-
B
tified byHSG had bilateral tubal occlusion and thuscould rely on
these devices for contraception despite unsatisfactory placement
as noted on HSG.
In a phase III multicenter clinical trial, 507 of the 518 women
enrolled underwent an attempt at bilateral device placement.[5]
In 11 women,micro-insert placement wasnot attempted because
of endometrium or uterine polyps blocking the ostia, inability to
visualize the ostia, or cervical stenosis. Bilateral placement of the
micro-inserts was successful in 464 of the 507 women (92%); this
was accomplished in one procedure in 446 women and in two
procedures in 18 women. Of the remaining 8% of women with
bilateral tubes in which bilateral placement was not achieved,
most of the failures were attributed to anatomic abnormalities.
Of the women with successful bilateral inserts, 96% had satisfactorily located inserts on HSG and 92% had bilateral tubal occlusion. Repeat HSG in 3 more months (total of 6 months after
C
the initial procedure) revealed bilateral occlusion in the women
who had correct placement of the micro-inserts but not complete tubal occlusion at 3 months on HSG. Thus, ultimately, 98%
of the women with successful bilateral micro-insert placement
were found to have bilateral tubal occlusion. Overall, 89% of the
women in whom micro-insert placement was attempted could
rely on the device.
To overcomedifficulty with cannulating tubes with anatomic
abnormalities, Conceptus developed a new coil catheter to help
cannulate areas of increased resistance.[11] The new design
includes a hydrophilic coating, animprovedflexible tip, a streamlined profile, and proximal pushability. With this new delivery
catheter, there was a 98% successful bilateral micro-insert placement rate;99% of the patients who had successful bilateraldevice
placementhadcompletetubalocclusionat 3monthsonHSG.[11]
Given the high rate of tubal occlusion after correct bilateral
placement of the Essure micro-inserts, eventually the 3-month
postprocedureHSGmaynotbeneeded.Thismayhelpexpandthe
use ofhysteroscopic sterilization intocommunities and countries
where resources and access to health care are limited or unavailable. In other countries,suchas Australia, the current recommendation by Conceptus is to check the location of the micro-inserts
by anabdominal radiograph at 3 months post placement. Several
studies support the useof ultrasound as a reliable method tocon-
Figure 8.5.8. Hysterosalpingogram 3monthsafterplacementofEssure
micro-inserts. HSG is performed 3 months post procedure to evaluate
micro-insert location andbilateraltubalocclusion.On this radiograph,
bilateral tubal occlusion is demonstrated.
firm micro-insert placement 3 months post procedure.[14,15]
Ultrasound could verify micro-insert placement and possibly
confirm tubal occlusion with the development of new echogenic
contrast media.
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Pregnancy Rates
In women who have had successful placement of theEssuredevice
and a 3-month postprocedure hysterosalpingogram demonstrating bilateral tubal occlusion, there have been no reported
intrauterine or ectopic pregnancies.[4–6] This 100% 1-year and
2-year effectiveness rate is encouraging. However long-term
follow-up is needed and data are still being collected. It is important to note that although the contraceptive efficacy is extremely
high if successful placement of the bilateral micro-inserts is
achieved, a portion of thepatientsundergoingthisprocedure(2%
to 15%) will not achieve successful bilateral placement and thus
will need to use an alternative form of birth control.[4–6,11,13]
Patient Tolerance and Adverse Events
Overall, the placement of the Essure micro-inserts is well tolerated by patients and is associated with a low complication
rate.[4,6,9,13] Patient satisfaction has been extremely high.[4,13]
Patients have had rapid return to normal function, which was
achieved by 60% of women within 1 day and by more than 75%
of the women by day 2 after the procedure.[5] Discomfort and
bleeding were two commonly associated symptoms.
In a large trial of more than 500 women, 65% of the study
participants rated the pain as either mild or none during the
procedure.[5] By discharge, 79% of the women rated the pain as
either mild or none.[5] In women who reported postprocedure
discomfort or pain, the pain was most commonly described as
similar to menstrual cramps.Postproceduralpain resolvedwithin
1 day, 3 days, and 1 week for 59%, 88%, and 99% of patients,
respectively.[4]
Bleeding and spotting were also commonly associated symptoms. In one study, mild postprocedural spotting was noted
in 34% of patients, but bleeding abated within 1 week for all
patients.[9] Similarly, in the multicenter phase II clinical trials,
83% of women who had a device placed reported some bleeding
after the procedure; almost all the patients (96%) stopped bleeding within 1 week.[4] The mean bleeding time was noted to be 3
days.[5]
The risk of other adverse outcomes, such as perforation, is
quite low. The perforation risk has been reported to be around
1%.[4,5,11] In the first multicenter phase II clinical trial, there
were six (3%) reported perforations of the uterine wall or tubal
lumen. In four of these cases, the perforation was thought to be
the result of a support catheter, which was subsequently discontinued. There were no significant complications from the perforations and no evidence of damage to the uterus or fallopian
tubes, inflammation, or adhesion formation in the four patients
who underwent a subsequent laparoscopic sterilization. In the
phase III trials, an adverse outcome rateof 4.5%was reported.[5]
More than two thirds of these “adverse outcomes” were the result
of micro-insert expulsion. The perforation rate was 1%, with no
clinical adverse events.
only option for women who haveundergone the Essure procedure
is IVF. Thereisa theoretical concern that theportion of thedevice
protruding into theuterine cavity could potentially interfere with
implantation. Kerin et al. [4] argue that there is progressive tissue
encapsulation of the deviceandthatthe device is madefrominert,
biocompatible materials, and thus the micro-insert is unlikely
to interfere with embryo transfer and implantation. However,
further studies will beneeded to evaluate the impactof the Essure
device on subsequent IVF.
OTHER PRODUCTS
Although Essure is the only FDA-approved hysteroscopic sterilization device, there are other products undergoing clinical trials
for transcervical sterilization.
Ovion
At the time of this writing, the Ovion system has not been FDAapproved for use in the United States and is currently undergoing clinical trials. The Ovion system is 1 mm in outer diameter
and can be placed through 3F working channels found in small
rigid or flexible hysteroscopes (Figure 8.5.9A). The micro-insert
is composed of a self-expanding nitinol frame embedded with
PET fibers that support tissue ingrowth (Figure 8.5.9B). Similar to the Essure system, the nitinol frame acutely anchors the
device in place, giving the PET fibers time to elicit the inflammatory response that leads to tissue ingrowth and subsequent tubal
occlusion. The micro-insert isplacedin the intramuralportion of
the fallopian tube. No portion of the device trails into the uterine
cavity. Both micro-inserts are loaded into the delivery catheter at
once, so theycan be deployed one afterthe other without removal
and replacement of the delivery catheter.Additionally, the microinsert is released through a one-step push of a button once the
correct location has been identified. This offers the benefit of
Delivery Catheter Handle
- Delrin
- ABS
- Polyolefin
A
Delivery Catheter Shaft
- Polytetrafluoroethylene (PTFE)
- Stainless Steel Microbraid
- PFBAX Outer Layer
Other Considerations
Similar to any other sterilization procedure, the Essure microinserts cause permanent occlusion of the fallopian tubes. It is
inevitable that some women who undergo the procedure will
regret their decision later in life and wishtobecomepregnant.The
B
Figure 8.5.9. The Ovion system. (A)TheOvionsystemis1mmin
outer diameter and can be placed through 3F working channels found
in small rigid or flexible hysteroscopes. (B) The micro-insert is made
up of a self-expanding nitinol frame embedded with PET fibers, which
support tissue ingrowth.
Hysteroscopic Sterilization — 171
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a shorter procedure with fewer maneuvers. During the limited
perihysterectomystudies,theproceduretime was less than5minutes, with a successful placement rate of 94%.[16]
The Ovion systemmay have several potential advantagesover
the current available device. First, compatibility with the flexible
hysteroscope allows for easier office use with less potential for
patient discomfort and lessneedfor anesthesia. In a small feasibility study,14of15women(93%)whohadthe Ovion system placed
through a flexible hysteroscope did not require any anesthesia
(local or intravenous). Additionally, the procedure may prove to
be faster, given that both micro-inserts are loaded into the same
delivery catheter and that the release mechanism involves only
the push of a button. Finally, no portion of the device protrudes
into the endometrial cavity. This could have potential benefits if
pregnancy via IVF is desired later or if other hysteroscopic procedures, such as endometrial ablation, are desired at the time of
or subsequent to device insertion.
Adiana
The Adiana transcervical sterilization system is currently undergoing clinical trials but is not yet approved by the FDA for clinical use at the time of this writing. This system uses a twostep approach to achieve tubal occlusion using an alternative
technology.[17] First, a controlled thermal lesion is created with
bipolar radiofrequency within the intramural portion of the fallopian tube.Next, a porousmatrix aboutthe size ofa grain of rice
is inserted within the tubal lumen, with no part protruding into
the uterine cavity. The thermal injury tothe endosalpinx removes
the surface epithelium and stimulates healing, with ingrowth of
healthy, vascularized tissue into thematrixpores.Tissueingrowth
both achieves occlusion of the tubal lumen and anchors the
matrix.
The 5F catheter is placed down a continuous-flow hysteroscope that has a 6F working channel. An electrolyte-free distention medium is necessary for uterine distention. A black mark
on the delivery catheter helps assure correct placement. Once
the catheter is properly positioned, as indicated when the black
marker is at the tubal ostia, the radiofrequency generator is activated. There is apositiondetectionarray and temperature sensors
distal to the black mark to provide feedback to the generator as
the tissues are heated (Figure 8.5.10). Once the tissue has been
satisfactorily heated, the matrix is then released from the tip of
the delivery catheter. Throughout the procedure, only the most
proximal 12 mm are cannulated.[18] As the thermally damaged
Figure 8.5.10. The Adiana system.
fallopian tube heals, healthy, vascularized tissue grows into the
porous matrix.
In one of the initial reports of the Adiana system, there was
successful placement of the device in 94% of the 376 women
undergoing attempt at placement.[19] In a more recent report of
a multicenter trial of 500 women, there was a similar successful
bilateral placement rate of 95%.[18] Of these 500 patients, 51%
underwent the procedure with only local anesthesia; the remainder had additional sedation. The mean procedure time was 12
minutes. The pregnancy prevention rate was 99.7% at 1 year.
There were no serious device-related adverse events noted.
CONCLUSION
Hysteroscopic sterilization offers patients an option for highly
effective permanent contraception that avoids incisions and the
need for general anesthesia and can be done in the office setting. It is well tolerated by the patient, affords rapid recovery and
resumption of normal activities, and is associated with a low rate
of adverse outcomes. Furthermore, hysteroscopic sterilization is
a great alternative for women in whom laparoscopy is especially
challenging and even contraindicated, such as those with obesity,
severe cardiopulmonary disease, or a history of prior abdominal
or pelvic surgery with known extensive adhesions.
REFERENCES
1. MacKay AP, Kieke BA Jr, Koonin LM, Beattie K. Tubal sterilization in the United States, 1994–1996. Fam Plann Perspect.
2001;33(4):161–165.
2. Westhoff C, Davis A. Tubal sterilization: focus on the U.S. experience. Fertil Steril. 2000;73(5):913–922.
3. Cooper JM. New approaches to hysteroscopic sterilization. Con-
temp Ob Gyn. 2003;48:8–20.
4. Kerin JF, Cooper JM, Price T, et al. Hysteroscopic sterilization
using a micro-insert device: results of a multicentrephase II study.
Hum Reprod. 2003;18:1223–1230.
5. Cooper JM, Carignan CS,Cher D,Kerin JF; Selective Tubal Occlusion Procedure 2000 Investigators Group. Microinsert nonincisional hysteroscopic sterilization. Obstet Gynecol. 2003;102(1):
59–67.
6. Kerin JF, Carignan CS, Cher D. The safety and effectiveness of
a new hysteroscopic method for permanent birth control: results
of the first Essure pbc clinical study. Aust N Z J Obstet Gynaecol.
2001;41(4):364–370.
7. Essure [package insert]. San Carlos, CA: Conceptus Inc.; 2002.
8. Valle RF, van HerendaelBJ.Newindications for hysteroscopy: sterilization. In: van Herendael BJ, Valle R, Bettochi S, ed. Ambulatory
Hysteroscopy: Diagnosis andTreatment . Chipping Norton, Oxfordshire, UK: Bladon Medical Publishing; 2004:143–151.
9. Valle RF, CarignanCS, Wright TC; STOP Prehysterectomy Investigation Group. Tissue response to theSTOPmicrocoiltranscervical
permanent contraceptive device: results from a prehysterectomy
study. Fertil Steril. 2001;76(5):974–980.
10. Estridge TD, Feldman DS. Quantification of vascular ingrowth
into Dacron velour. J Biomater Appl. 1991;6(2):157–169.
11. Kerin JF, Munday DN, Ritossa MG, Pesce A, Rosen D. Essure
hysteroscopic sterilization: results based on utilizing a new coil
catheter delivery system. J Am Assoc Gynecol Laparosc. 2004;11(3):
388–393.
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12. Glantz JC, Shomento S. Comparison of paracervical block
techniques during first trimester pregnancy termination. Int J
Gynaecol Obstet . 2001;72(2):171–178.
13. Ubeda A, Labastida R, Dexeus S. Essure: a new device for hysteroscopic tubal sterilization in an outpatient setting. Fertil Steril.
2004;82(1):196–199.
14. Kerin JF, Levy BS. Ultrasound: an effective method for localization of the echogenic Essure sterilization micro-insert: correlation
with radiologic evaluations. J Minim Invasive Gynecol. 2005;12(1):
50–54.
15. Thiel JA, Suchet IB, Lortie K. Confirmation of Essure microinsert tubal coil placement with conventional and volume-contrast
imaging three-dimensional ultrasound. Fertil Steril. 2005;84(2):
504–508.
16. Robles R, Isaacson K. Placement of a transcervical tubal occlusion device through a 3.5-mm O.D. flexible hysteroscope. J Minim
Invasive Gynecol. 2005;12(5):S40.
17. Abbott J. Transcervical sterilization. Best Pract Res Clin Obstet
Gynaecol. 2005;19(5):743–756.
18. Price T, HerbstS,Harris M, Prethus J,AndersonT, Garinger D.Permanent transcervical sterilization: the first 500 womentreated in a
multi-center trial. Presented at the American Collegeof Obstetrics
and Gynecology, 53rd Annual Meeting, San Francisco, CA, May
9–11, 2005.
19. Vancaillie T. Adiana hysteroscopic sterilization: interim results of
the EASE clinical trial. Presented at the American Association of
Gynecologic Laparoscopists Global Meeting; November 12, 2004;
San Francisco, CA.
Section 8.6. Global Endometrial Ablation
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Philip G. Brooks
In general, abnormal uterine bleeding has been recognized as
a frequent and serious problem affecting women for hundreds
of years. Its management has included attempts at destruction of
the endometrium, especially for women who refusehysterectomy
or are poor candidates for major surgery. Previous methods of
endometrial ablation included injection of sclerosing chemicals
and drugs into the uterine cavity, delivery of ionizing radiation
to the uterine cavity, and photoinactivation of the uterine lining, all of which were too toxic or too unsuccessful to be widely
used. Prompted by the revolutionary miniaturization of hysteroscopes, the improvement in safety and effectiveness of distention
media, and the successful development of cold light transmission, intrauterine exploration and surgical techniques developed
rapidly and gave rise to investigation of ways to reduce the bleeding. Thefirst breakthrough occurred in1981 when Goldrath et al.
[1] reported the development of hysteroscopically directed laser
endometrial ablation, and the hope for effective, relatively safe,
minimally invasive hysteroscopic ablation became reality.
This first technique used Nd:YAG laser energy delivered
through the operative channel of the hysteroscope via a fiber.
The results were very satisfactory, but because of the expense
of the equipment and the fears of complications by less-skilled
operators, the procedure was limited to a handful of well-trained
hysteroscopists.
The next and most significant stimulustothefieldofendometrial ablation for the conservative management of abnormal
bleeding wasthe adaptationof the urologic resectoscope to gynecologic operative procedures. Hallez et al. [2], Neuwirth and
Amin [3], and DeCherney and Polan [4] in the English-speaking
literature and Lin [5] in the Japanese literature published reports
on the successful management of such bleeding using electricity
and resecting loops. As the number of cases accumulated, data
presented to theU.S. Food and Drug Administration (FDA) were
sufficient to warrant approval of the resectoscope for gynecologic
indications in December 1989.[6] Subsequently, the lower cost,
the equaleffectiveness,and the greater ease ofteaching and learning this technique resulted in the resectoscope becoming the gold
standard for the management of abnormal uterine bleeding.
Despite intensive interest by both resectoscope manufacturers and teachers in training students and practicing physicians,
the number of resectoscopic endometrial ablations grew slowly
and the number of hysterectomies forabnormal uterine bleeding
in the United States did not decrease. Complications due to electrical injuries of adjacent or adherent organs (bowel, bladder, or
blood vessels) or due to excessive absorption (intravasation) of
the sodium-free solutions required to complete these procedures
have prompted theleaders in this field to seek other methods that
ablate the endometrium and destroy the vascular supply to the
underlying stroma in a more user-friendly, safe, and consistent
manner.
The following text describes the new technologies approved
by the FDA for endometrial ablation. Currently they include
the Thermachoice (Gynecare), NovaSure (Cytyc), Cryogen
HerOption
Endometrial Ablation, Microsulis Medical Limited), and HTA
(HydroThermAblator, Boston Scientific) devices. FDA phase III
studies required all these devices to be evaluated with standardized measuring of pre- and posttreatment blood loss, and to be
compared with resectoscopic ablations in randomized, prospective trials. The presentation that follows attempts to describe the
methodology, potential risks incurred in using the devices, complications reported to the FDA, and outcomes as reported to the
FDA during the phase III studies and follow-up of the patients.
THERMACHOICE
TM
(American Medical Systems), MEA (Microwave
Methodology
The Thermachoice system incorporates an intrauterine balloon
(Figure 8.6.1) originally made of latex then changed to silicone
to avoid the risk of latex allergy and to increase the pliability
of the balloon to better conform to the configurations of the
endometrial cavity and cornual areas. The balloon is inserted
into the uterus via a 5-mm sheath. The balloon is then filled with
saline solution, maintained at an intrauterine pressure of 160 to
180 mm Hg, and the liquid is heated to 87
◦
C for 8 minutes.
Risk Factors
Because the device is inserted blindly into the endometrial cavity,
there is a risk of partial or complete perforation of the uterus. A
cavity integrity test, performed by injectingfluid through a channel in the inserter before heating the saline, attempts to avoid this
risk. The device can be activated within a partial perforation of
the uterine wall and with part of the balloon being in the cervical canal. The obvious fear of rupture of the balloons, with spill
of hot saline into the vagina, has not been seen as the integrity
of the balloons is tested before packaging. Through September
2004, 273 adverse events were reported to the MAUDE (Manufacturer and User Facility Device Experience) database of the FDA,
including several deaths, 72 severe adverse events, and numerous
bowel injuries.[7]
Outcomes
Thermachoice is the only device that has 5-year follow-up
data: 23% of patients had amenorrhea, and overall success (as
173
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Figure 8.6.1. The ThermachoiceTMsystem, showing console and disposable hand-piece with intrauterine balloon.
determined by menstrual scores and patientsatisfaction,etc.) was
reported as 68%. Hysterectomies were performed in 16% of the
originally studied patients undergoing Thermachoice endometrial ablations, as noted in the 5-year follow-up report. The
original FDA phase III studies required that all patients have a
dilatation and curettage immediately before undergoing a Thermachoice endometrial ablation.
NOVASURE
Methodology
The NovaSure system is composed of an expandable wire mesh
array (Figure 8.6.2) that is compressed into a 7.2-mm sheath
when inserted into the uterus, then expands to fit the cavity. The
semirigid mesh delivers bipolar electrical energy until electrical
resistance (impedance) is complete, transmitting no more electrical energy through the electrically “dead” cells.
Figure 8.6.2. The NovaSureTMsystem showing console and disposable
wand with expandablewiremesh array at distal end.(CourtesyofCytyc
Corporation and affiliates)
Unfortunately, according to the MAUDE database reports after
the modification was instituted, there have been additional serious adverse events, including bowel burns.
Outcomes
Despite the number of complications reported tothe FDA, NovaSure endometrial ablationsarefastand effective. At the 24-month
follow-up of the phaseIIIstudy, amenorrhea wasreportedin 47%
of patients, with a 92% satisfaction rate.The meanprocedure time
was 4.32 minutes, about one tenth as long as the resectoscopic
ablation procedures. No pretreatment of the endometrium was
required or provided in the FDA trials for this method.
Risk Factors
Because the device also is inserted blindly into the endometrial
cavity, there is a risk of partial or complete perforation of the
uterus and a risk of extrusion or inadvertent placement into the
upper cervical canal. A cavity integrity test, performed by injecting carbon dioxide through achannelinthe sheath before activating the electricity, attempts to avoid this risk. Before activation,
a negative pressure (suction) draws the uterine wall into closer
apposition to the bipolarwand,andthe negativepressureis maintained throughout the procedure. If the suction is broken (e.g.,
by an unrecognized perforation), the controller rapidly stops the
flow of electricity. Despite thesesafety features, the FDA MAUDE
database cites numerous serious adverse events, including bowel
burns and uterine perforations. A recent modification to the system was instituted whereby once the system stops because of
an alarm, the alarm and stoppage cannot be overridden. This
modification was intended to prevent the alarm from being overridden, as occurred in the past, with very serious consequences.
CRYOGEN
Methodology
The Cryogen, or HerOption, system (Figure 8.6.3) uses a 5.5mm metal-tipped probe inserted first into one cornu and then
the other to deliver a liquid nitrogen coolant at −90
◦
Ctoeach
area,generating a cytotoxicfreezezone.Treatment time is approximately 10 to 15 minutes, depending on the decision of the surgeon and the size of the uterine cavity. Requirements by the
FDA include concomitant sonographic monitoring to ensure the
uterine myometrial thickness is adequate to prevent transmural
spread of damaging temperatures to adjacent or adherent bowel
or bladder.
Risk Factors
In addition to the risk of inadvertent perforation due to blind
insertion, the probe may be activated in a false passage or in
Global Endometrial Ablation — 175
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Figure 8.6.3. The Cryogen, or HerOptionTM, system, showing console (top) and disposable a 5.5-mm metal-tipped probe that is inserted into the
uterus (bottom).
the endocervical canal. In addition, since 2002, despite a very
small number of procedures performed in the United States,
the MAUDE database has reported 11 serious adverse events,
including six internal bowel injuries associated with the use of
this device, some in the absence of documented uterine perforation.[7]
Outcomes
At 36 months, the amenorrhea rates are only 26% – among the
lowest of all the global techniques. In addition, the hysterectomy
and retreatment rates totaled 11%. Of special note is the fact that
in the original 12-month FDA trial, over 25% of the procedures
had a mechanical failure at the time of the original procedure,
resulting in the cancellation of the procedure or the need to open
another kit.
MICROWAVE ENDOMETRIAL ABLATION
Methodology
The MEA system consists of a computerized controller and a
7-mm disposable probe (Figure 8.6.4) inserted blindly into the
uterine cavity and then gradually withdrawn through the cavity with continued sweeping motions. The uterine temperature
is monitored on a dial, and safety and efficacy are achieved by
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Figure 8.6.4. MEATMsystem, showing a 7-mm disposable intrauterine probe, which is inserted and manipulated inside the uterine cavity (left),
and the diagram of the action inside the uterus (right).
observing that the temperature remains in the prescribed zone.
FDA phase III trials used GnRH agonists as pretreatment, but
subsequent studies showed no difference in outcomes with or
without pretreatment. The average treatment time is 11 minutes,
including diagnostic hysteroscopy.
Risk Factors
Because the probe is inserted into the uterus and manipulated
blindly, there are risks of perforation of the uterine wall and
inadvertent damage to the endocervix. In addition, as a result
of a number of bowel injuries in patients in whom no perforation was detected [7], the FDA approved the device with the
mandate thatuterine wall thickness must be ascertained by ultrasound before the procedure and diagnostic hysteroscopy must be
performed after cervical dilatation but before the probe is placed
inside the uterus.
Outcomes
Three-year results of the multicenter randomized FDA phase III
trials demonstrateda very highamenorrhea rate.[8] Sixtypercent
of patients reported no menses, and overall success was reported
to be 97%.
HYDROTHERMABLATOR
Methodology
The HTA system (Figure 8.6.5A) is the only system for global
endometrial ablation that is performed under constant visualization – that is, it uses hysteroscopy to determine that the sheath is
placed in the right spotand to make sure itstaysthere throughout
the procedure. Thetelescope, any 3-mm hysteroscope, fits within
a 7.8-mm polycarbonate sheath that allows the circulation of
physiologic saline solution into the uterine cavity by gravity. The
saline fluid bag is placed at a prescribed height to produce an
intrauterine pressure to about 50 mm Hg. Initially the fluid is
room temperature, and the computerized console monitors the
volume to ascertain that a watertight seal exists. Once the computer confirms the seal, the operator activates the heating system
and the fluid is heated to a temperature of 90
◦
C for 10 minutes,
resulting in the sealing of the vessels and the destruction of the
surface epithelium. Because there is no rigid wand or confining
balloon, the fluid can flow to all parts of the endometrial cavity, getting the destructive heat energy to a greater area than is
achievable with probes, balloons, or wands. The original FDA
study included preprocedure thinning of the endometrium with
the use of an injectable GnRH agonist, Depo Lupron (TAP Pharmaceuticals), but recent reports confirm that this is unnecessary
as it adds nothing to the success of the procedure in terms of
control of the bleeding.
Risk Factors
Since the entire procedure is performed under direct visualization, the risk of perforation and internal organ damage is exceedingly low. The major risk appears to be the spill of hot saline into
the vagina due to leakage through the cervix or from premature
withdrawal of the sheath before adequate cooling of the liquid.
Since 2002, the MAUDE database has reported only two internal
injuries with the HTA procedure, one due to a known perforation – after which the procedure continued anyhow, against
the manufacturer’s instructions – and the other in a procedure
wherein concomitant laparoscopy with intra-abdominal electrosurgery was performed, with no clear-cut definition as to which
procedure caused the burn. A modification of the equipment
recently was adopted by the manufacturer: the attachment of a
tenaculum-stabilizing device (Figure 8.6.5B) that prevents inadvertent removal or slipping of the sheath through or out of the
cervix before intended. Leakage of heated liquid through the
oviducts has never been seen because intrauterine pressures is
maintained at a level too low to overcome minimum cornual
opening pressures.
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