(CASE REPORT)
Wi Liong, Eddy Hartono
Department of Obstetrics and Gynecology
Faculty of Medicine Hasanuddin University
Wahidin Sudirohusodo General Hospital
Makassar
INTRODUCTION
Menorrhagia is a common clinical problem and makes a large contribution to the workload of gynecologists. Dysfunctional uterine bleeding (DUB) affects 20-30% of women and accounts for 12% of gynecological referrals. Sixty percent of these women will have undergone hysterectomy within 5 years of referral, making it the commonest major gynecological operation. The recent VALUE Survey of over 36,000 hysterectomies reported a mortality rate of 0.38 per 1000 operations and serious morbidity rate of 3% (bleeding, visceral injury and other complications).
Endometrial ablation is a procedure that aims to destroy the endometrial lining of the uterus, causing a reduction or elimination of menstrual bleeding. To suppress menstrual bleeding effectively, it is necessary to remove the full thickness of the endometrial lining as well as the superficial myometrium. The endometrial tissue may be destroyed either by excision with an electrosurgical loop, or by ablation using an energy source which has sufficient power to produce necrosis of the entire thickness of the endometrium as well as the superficial myometrium.
Recently, several ablative techniques have been described to treat menorrhagia in order to reduce hysterectomy rates. Because the majority of women with menorrhagia have a normal sized uterus with no obvious pathology, endometrial ablation are increasingly performed. With the development of minimal access techniques, it has become possibly to destroy the endometrium in situ, in a short, day-care operation. These techniques include endometrium ablation with a Nd:YAG laser and resection of the endometrium with the operative hysteroscopy. Unfortunately, these techniques require considerable surgical skill and a long learning curve. It has been suggested that a surgeon learning the technique of resection, should treat 200 cases. Although resection is considered to be safe, it is still associated with a mortality of 2 per 10,000 and a serious complication rate of 2.1-6.4%.
Figure 1. Operative hysteroscopy with wire loop electrode and rollerball.
Common complications of endometrial ablation are mechanical complications (cervical laceration and uterine perforation), distending-media-related complications (embolism, fluid overload, hyponatremia, pulmonary edema, intravascular coagulation), bleeding and infection.
Endometrial ablation techniques are termed first-generation or second-generation. First-generation techniques [which include transcervical resection of the endometrium (TCRE), rollerball endometrial ablation (RB), TCRE/RB and Nd:YAG laser endometrial ablation] use a hysteroscope and fluid medium, and require a high level of technical skill. Second-generation endometrial ablation techniques are newer techniques which are usually nonhysteroscopic, do not require a fluid medium, and require less training to perform.
Second-generation endometrial ablation techniques are microwave endometrial ablation (MEA), thermal balloon endometrial ablation (TBEA), hydrothermal ablation, radiofrequency electrosurgery, cryoablation, endometrial laser intrauterine thermal therapy (ELITT).
Figure 2. Thermal Balloon Endometrial Ablation
Figure 3. Hydrothermal Endometrial Ablation
The use of media to distend uterus cavity is critical for panoramic inspection of uterine cavity in the first-generation techniques. Without media, the uterus is a narrow slit. Uterine distention during hysteroscopy improves visualization by separating the surfaces of the uterine cavity and creating sufficient pressure to inhibit intracavitary bleeding; however, the most serious hysteroscopic complications are related to excessive absorption of distending media. Intrauterine pressures needed to adequately view the endometrium are proportional to the muscle tone and thickness of the uterus. A pressure of 75 mmHg is adequate for uterine distention. Rarely is more than 100mmHg required, and higher pressure can result in increased risk of intravasation media. The refractive index of each medium option affects magnification and visualization of the endometrium.
Excessive fluid absorption or idiosyncratic reactions to distending media can occur during either diagnostic or operative hysteroscopy. The ideal distending media is isotonic, nonhemolytic, nonconductive, nontoxic, rapidly cleared from the body, and provides ample visualization. In fact, the ideal distending media does not exist; therefore, the hysteroscopist is left with several choices of media, each with certain advantages and disadvantages.
The operating time is important because more fluid absorption occurs during lengthier cases. The surgeon must operate quickly, as well as safely, and be willing to stop a procedure when fluid management becomes problematic. Excess fluid absorption can occur even when pressures are well controlled and surgery progresses appropriately. This means the most important factor in preventing fluid overload is the accurate monitoring of inflow and outflow, keeping track of the difference between them, known as the fluid deficit.
The most commonly used media are gases, low viscosity fluid and high viscosity fluids.
CASE REPORT
- A 46-year-old female, PIII A0 who complained of bleeding for the last ten months. She has been treated with hormonal therapy, and dilatation and curettage (D&C), hystopathological examination revealed simple endometrial hyperplasia. USG showed normal sized uterus, irregular and thick endometrium, and normal adnexa. Then, she underwent monopolar TCRE/RB endometrial ablation.
- A 43-year-old female, PII AI, who complained of prolonged periods (more than two months). She responded poorly to hormonal therapy. Afterwards, she underwent monopolar TCRE/RB endometrial ablation. During diagnostic laparoscopy, subserous leiomyoma is found, therefore laparoscopic leiomyoma enucleation was also done.
- A 46-year-old female, PVII A0, who complained of irregular menstrual bleeding for the last two years. She has been treated with hormonal therapy and D&C, hystopathological examination revealed simple endometrial hyperplasia. Thus, she underwent monopolar TCRE/RB endometrial ablation and laparoscopic bilateral tubectomy as she requested.
All three patients above underwent endometrial ablation, using 5% Dextrose as a distending media. Until now, they all have been being amenorrhea for more than a year.
DISCUSSION
Endometrial ablation techniques, which had been done to the three patients, is TCRE/RB. TCRE/RB is a combination of two procedures (TCRE and RB). This technique is considered the gold standard for endometrial ablation by most experts in the fields.
The procedure involves using the rollerball at the cornual region and the isthmus where the myometrium is thinnest, and the loop electrode (TCRE) to excise the remainder of the endometrium.
The advantages of TCRE are that enables histological assessment of excised endometrium and also enables submucous fibroids and polyps to be excised if present. The uterine distention media used during TCRE must be electrolyte-free, and this increases the risk of hyponatraemia if excess fluid is absorbed during the procedure.
A further disadvantage of TCRE is that it is associated with a higher risk of uterine perforation than other endometrial ablation techniques, but the risk is lower when TCRE is combined with RB.
RB is similar to TCRE; however, instead of a loop electrode excising the endometrium, a rollerball electrode is used to systematically coagulate the endometrium. As with TCRE, the fluid media used must be electrolyte-free, increasing the risk of hyponatraemia if excess fluids is absorbed.
The advantage of fluid over gas is the symmetric distention of the uterus with fluid, as well as its capacity to flush blood, mucus, bubbles, and small tissue fragments more effectively out of the visual field. Both low-viscosity and high-viscosity fluid media can be used for distention.
1. High-viscosity Fluid:
The only high-viscosity medium available is dextran 70 or Hyskon, which is 32% dextran 70 in 10% dextrose in water. Dextran is a high-molecular weight substance of 70,000 d. It is a nonelectrolytic, nonconductive fluid that can be applied in operative and diagnostic procedures. Because of its high viscosity, dextran 70 is immiscible with blood and has minimal leakage through the cervix and tubes, allowing for excellent visibility during surgical procedures.
However, avoid more than 500 mL of absorption to prevent fluid overload because it is a volume expander with a high risk of pulmonary edema. With each 100 mL of dextran 70 is absorbed, the intravascular volume is increased by 800 mL. This medium has a large adverse effect profile, including allergic reactions and anaphylaxis, adult onset respiratory distress syndrome (ARDS), fluid overload, pulmonary edema, disseminated intravascular coagulopathy, and destruction of instruments (which must be cleaned shortly after use because the solution can stick to the equipment).
2. Low-viscosity Fluid:
There are two types of low-viscosity distending media: those that contain electrolytes and those that do not. Two types of electrolyte-containing fluids exist, sodium chloride (0.9% sodium chloride, which is 154 mEq/L sodium and chloride) and acetated Ringer solution. These solutions can be used for diagnostic hysteroscopy as well as for limited operative procedures.
Operative procedures using mechanical, laser, or bipolar energy are safe. Both options are readily available, and complex equipment is not needed.
Two major disadvantages are associated with these solutions. They are miscible with blood, obscuring visibility with bleeding and thus requiring larger volumes to clear the operative field, and they are excellent conductors, which precludes procedures that use monopolar.
The nonelectrolyte fluids consist of 5% mannitol, 3% sorbitol, 1.5% glycine, and 5% dextrose. These fluids do not conduct electrical current and allow for better visualization when bleeding occurs. The common disadvantage of all the nonelectrolyte media is their risk of overload from intravascular absorption (particularly >2 L), which requires fluid monitoring during use.
However, 5% mannitol can be used only with monopolar operative procedures. It is broken down by the liver to glycogen and excreted through the kidney, with a half-life of 100 minutes. If 5% mannitol is administered intravenously, it remains in the extracellular compartment when intravasation occurs with this media, fluid and electrolyte imbalances can result in pulmonary edema, which can be treated with a diuretic.
The 3% sorbitol is broken down by the liver to fructose and glucose, which increases postoperative risks of hyponatraemia and hyperglycemia, hemolytic or signs of hypervolemia.
Use caution when 1.5% glycine is used in a patient with impaired hepatic function because glycine is metabolized to ammonia and serine.
Overload with glycine may produce:
a. Nausea and vertigo
b. Hyponatraemia
c. Transient hypertension followed by hypotension associated with confusion and disorientation
d. Excess overload may produce elevated blood ammonia levels leading to encephalopathy and rarely, death.
Karci and Erkin report the case of a woman who developed transient blindness following hysteroscopic myomectomy in which a total of 800 mL of 1.5% glycine was used as the irrigation solution.
Complications with the use of 5% dextrose are very rare. In fact, there are no reports in the world literature of major morbidity or mortality with the use of 5% dextrose at hysteroscopy.
Possible complications include:
- Water intoxication (a reduction in serum osmolality) with a dilutional reduction in sodium concentration,
- Volume overload (when the circulating volume in the vascular system exceeds the ability of the heart to adequately pump this volume and the excess fluid typically begins to collect in the tissue of the lungs),
- Hypothermia (significant excess in circulating glucose concentration that may not be rapidly metabolized if the patient has insulin resistance or diabetes mellitus).
The major complication that most hysteroscopic surgeon’s focus on avoiding is water intoxication. The risk of water intoxication from 5% dextrose in a healthy woman with normal renal function is very low, since the kidneys can typically produce in excess of 1000 cc of dilute urine in response to a decrease in serum osmolality.
Besides the advantages quoted above, 5% dextrose is easier to get and cheaper than other fluid distending media.
All three cases reported are treated by endometrial ablation using 5% dextrose as a distending media and the results are satisfying.
Visualization from using 5% dextrose is adequate, therefore ablation procedure could be done with minimum difficulties. This procedure is considered success because the three patients have been being amenorrhea for more than a year.
Prevention of fluid overload (media-related complication) may be accomplished by:
1. Using appropriate distending media and delivery system
2. Keeping operating time to a minimum
3. Avoiding entering the vascular channels
4. Keeping fluid pressures below 80 mmHg and gas pressures below 100 mmHg
5. Meticulous accountancy of fluid balance
6. The procedure must be abandoned if the deficit rises to 2 litres or there is evidence of venous congestion
Besides, distending media absorption can be decreased by using GNRH analog or intracervical diluted vasopressin preoperatively.
Second-generation endometrial ablation techniques do not use a hysteroscope, therefore complications related to distending media can be avoided. But these techniques involve relatively high equipment purchase and utilization costs.
Further researches about safety and effectivity of endometrial ablation, especially related to distending media are highly needed.
CONCLUSION
TCRE/RB endometrial ablation using 5% dextrose as distending media has been done to three endometrial hyperplasia cases, and the results are satisfying.
REFERENCES
<!–[if supportFields]> ADDIN EN.REFLIST <![endif]–>1. Munro MG. Dysfunctional uterine bleeding: advances in diagnosis and treatment. Curr Opin Obstet Gynecol. 2001;13:475-89.
2. Fernandez H, Kobelt G, Gervaise A. Economic evaluation of three surgical interventions for menorrhagia. Human reproduction. 2003;18(3):583-7.
3. Endometrial ablation techniques for chronic refractory menorrhagia. Canberra: The Medical Services Advisory Committee (MSAC); 2005.
4. Lessard C, Framarin A. Endometrial ablation techniques in the treatment of dysfunctional uterine bleeding. Montreal: Agence d’Evaluation des Technologies et des Modes d’Intervention en Sante (AETMIS); 2002.
5. Shaw JA, Shaw HA. Menorrhagia. 2005 [cited 2006 06/04]; Available from: http://www.emedicine.com
6. Gervaise A, Fernandez H, Capella-Allouc S, Taylor S, La Vieille S, Hamou J, et al. Thermal balloon ablation versus endometrial resection for the treatment of abnormal uterine bleeding. Human reproduction. 1999;14(11):2743-47.
7. Munro MG. Abnormal uterine bleeding: surgical management-part III. J Am Assoc Gynecol Laparosc. 2000;7(4):18-47.
8. League DD. Endometrial ablation as an alternative to hysterectomy. AORN J. 2003;77(2):322-38.
9. Cameron LT. Menstrual disorders. In: Edmonds DK, editor. Dewhurst’s textbook of obstetrics and gynaecology for postgraduates. 6th ed. London: Blackwell Science Ltd; 1999. p. 410-9.
10. Baggish MS. Operative hysteroscopy. In: Rock AJ, Jones HW, editors. Te Linde’s operative gynecology. 9th ed. Philadelphia: Lippincott Williams & Wilkins; 2003. p. 379-411.
11. Carlson KJ, Schiff I. Alternatives to hysterectomy for menorrhagia. N Engl J Med. 1996;335(3):198-9.
12. Pinion SB, Parkin DE, Abramovich DR, Naji A, Alexander DA, Russell IT, et al. Randomised trial of hysterectomy, endometrial laser ablation, and transcervical endometrial resection for dysfunctional uterine bleeding. BMJ. 1994;309:979-83.
13. Daiter E. Advanced operative hysteroscopy and laparoscopy. [cited 2006 06/04]; Available from: http://www.obgyn.net
14. Julian TM. Hysteroscopic complications. Journal of Lower Genital Tract Disease. 2002;6(1):39-47.
15. Guido RS, Stovall DW. Hysteroscopy. [cited 2006 06/04]; Available from: http://www.isge.org
16. Chan SCS, Fraser IS. The role of diagnostic hysteroscopy in modern gynaecological practice. HKMJ. 1995;1(2):161-6.
17. Nagele F, Wieser F, Deery A, Hart R, Magos A. Endometrial cell dissemination at diagnostic hysteroscopy: a prospective randomized cross-over comparison of normal saline and carbon dioxide uterine distension. Human reproduction. 1999;14(11):2739-42.
18. Petrozza JC, Sikking E. Hysteroscopy. 2005 [cited 2006 03/04]; Available from: http://www.emedicine.com
19. Karci A, Erkin Y. Transient blindness following hysteroscopy. The Journal of International Medical Research. 2003;31:152-5.
20. Homer HA, Li TC, Cooke ID. The septate uterus: a review of management and reproductive outcome. Fertility and Sterility. 2000;73(1).
21. Indman PD, Brooks PG, Cooper JM, Loffler FD, Valle RF, Vancaillie TG. Complications of fluid overload from resectoscopic surgery. J Am Assoc Gynecol Laparosc. 1998;5(1):63-7.
22. Valle RF. Facilitating and implementing hysteroscpy for over a century. J Obstet Gynecol Ind. 2002;52(1):28-32.
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