Air embolism during transcervical resection of endometrium

Monitoring of Gas Emboli During Hysteroscopic Surgery: A Prospective Study

OBJECTIVES

Previous studies have demonstrated a high frequency of gas emboli during hysteroscopy, but guidelines for the prevention, early detection, and intervention of gas embolism during hysteroscopic procedures are still lacking. This study aimed to gain a clearer understanding of risk factors and specific signs and symptoms associated with gas emboli.

METHODS

This prospective study enrolled 120 women scheduled for hysteroscopy using 5% glucose as distension medium. The gas bubbles were monitored sequentially in internal iliac vein, common iliac vein, inferior vena cava, superior vena cava, heart, and pulmonary artery under the gray-scale imaging of Doppler ultrasound. The frequency, extent, and the hemodynamic and respiratory effects of gas emboli were evaluated. The interventions and outcomes were recorded. The risk factors associated with gas emboli, and their relationship with the frequency and extent of gas emboli, were assessed.

RESULTS

In our study, evidence of gas emboli under Doppler ultrasound monitoring was observed in 44 (36.7%) patients. The operation was continued and finished as soon as possible for patients presenting with stable vital signs or transient hemodynamic and respiratory changes, which resolved spontaneously without intervention. The operation was paused for patients presenting with significant hemodynamic changes or loss of consciousness, and the operation was resumed shortly after resumption of stable vital signs following symptomatic treatment. All patients in our study finished the operation and recovered without developing serious complications. Data analysis showed prolonged procedure duration and increased bleeding volume were both positively correlated with the frequency and extent of gas emboli.

CONCLUSION

Our study demonstrated a high frequency of gas emboli during hysteroscopy. Doppler ultrasonic monitoring combined with a clearer understanding of specific signs, symptoms, and risk factors will facilitate early detection and intervention of gas emboli during hysteroscopy.

Outcomes-based systematic review for management of massive intra-cardiac or pulmonary thrombotic emboli during surgery

INTRODUCTION

The management of massive intra-operative embolism remains controversial. Our hypothesis was that either surgical or medical thrombectomy offers survival benefit in these patients.

METHODS

Published case reports were reviewed for intra-operative intra-cardiac or pulmonary embolism and outcomes for the following four intervention groups were evaluated for mortality benefit: surgical embolectomy; thrombolysis; anticoagulation; supportive care alone. We also assessed whether the use of diagnostic modalities prior to each embolism event resulted in a mortality benefit and, separately, whether post-intervention improvement in physiologic parameters resulted in improvement in outcomes. Univariate analyses and logistic regression were performed to assess the impact of the four primary interventions on mortality, the primary outcome.

RESULTS

Seventy-eight cases were reviewed and therapeutic interventions resulted in improved survival (70%) compared to supportive care (45%), odds ratio=0.38[0.15-0.98], p=0.04. Univariate analysis of primary interventions with death as a primary outcome resulted in a lack of significantly different outcomes (p=0.08). Mortality rates were 71% in the thrombolytic; 28% in surgical embolectomy; 18% in anticoagulation and 43% in the supportive care groups. The routine pre-event use of trans-esophageal echocardiography was not related with improved outcomes (p=0.36) but the use of pulmonary artery or central venous catheters was (p=0.035). Post-intervention improvements in the physiologic parameters of each diagnostic modality were associated with an improvement in mortality (p<0.05).

CONCLUSIONS

Our data present some important trends among the intervention groups, raising significant concerns about the safety for the use of thrombolytics in the management of intra-operative embolism.

Probable gas embolism during operative hysteroscopy caused by products of combustion

PURPOSE

Gas embolism is a rare but well documented entity during operative hysteroscopy, with an incidence of 10-50%. Catastrophic outcomes occur at a rate of three in 17,000 procedures. The purpose of this report is to present a non-fatal case of gas embolism probably caused by the gaseous products of combustion.

CLINICAL FEATURES

A 50-yr-old woman with a history of menorrhagia was scheduled for hysteroscopy and endometrial ablation and polypectomy. Fifteen minutes into the procedure, with the patient in lithotomy position, 20 degree head down tilt, and breathing spontaneously, a sudden oxygen desaturation occurred from 97% to 87%. The patient's end-tidal carbon dioxide dropped from 46 mmHg to 27 mmHg. The patient's breathing pattern remained normal, respiratory rate remained 11-12 breaths x min(-1) but amplitude of the reservoir bag movement was increased. Cardiovascular variables remained stable. She responded rapidly to 100% oxygen and made an uneventful recovery. Having ruled out other possible causes, we concluded gas embolism was responsible for the fall in oxygen saturation and end-tidal CO(2).

CONCLUSION

With all the precautions in place to minimize the likelihood of fluid overload and ambient air embolism occurring, we surmised that products of combustion were the cause of the gas embolism. During endometrial ablation, gaseous products of combustion, mainly carbon dioxide, accumulate. The gases may then contribute to the rise in uterine pressure that occurs as irrigation fluid enters the uterus and this rise in pressure in turn encourages passage of gas into the open venous sinuses.

Venous air and gas emboli in operative hysteroscopy

Air and gas emboli have been reported in almost all areas of clinical and surgical practice. The literature is replete with observations and methods for treating these events. It is possible to mitigate the consequences of this risk, particularly in operative hysteroscopy. Recommendations include monitoring devices such as capnography to facilitate intraoperative diagnosis of these emboli.

Microwave endometrial ablation: development, clinical trials and outcomes at three years

OBJECTIVE

To describe the introduction of microwave endometrial ablation to clinical practice, and to report the outcomes three years after endometrial ablation.

DESIGN

A clinical trial using prototype microwave endometrial ablation equipment.

SETTING

District general hospital.

POPULATION

Forty-three women with completed families and with failed medical management for menorrhagia were treated with microwave endometrial ablation between October 1994 and April 1995.

MAIN OUTCOME MEASURES

A statement of perceived menstrual loss and satisfaction supported by a menstrual symptom questionnaire score. Dysmenorrhoea was graded as a measure of described severity. Treatment time.

RESULTS

Forty-three women had a total of 46 treatments. Mean treatment time: n = 43, was 141 seconds (50-310). Amenorrhoea: n = 16; 37.2%. Very light periods/discharge: n = 11; 25.6%. Improved periods and woman satisfied: n = 9; 20.9%. Improved periods and woman not satisfied: n = 1; 2.3%. Overall satisfaction at three years is 83.7%. Moderate (55.8%) or severe (27.9%) dysmenorrhoea pre-operatively had improved to 11.6% and 6.8% respectively at three years. Three re-treatments and four hysterectomies will be discussed.

CONCLUSIONS

Microwave endometrial ablation is a new treatment for dysfunctional uterine bleeding using the application of microwave energy to the endometrium. This results in a rapid but restricted depth of intrauterine heating avoiding hysteroscopic fluid, operative haemorrhage and earthing risks. The technique is simple to learn and perform. Women report a high level of satisfaction three years after microwave endometrial ablation.

Venous air embolism during operative hysteroscopy

The world literature, including hospital and medicolegal case records, was reviewed to collate cases of venous air embolism resulting from the increasing number of operative hysteroscopies being performed. Seven women undergoing operative hysteroscopy for five different indications had clear-cut evidence of venous air embolism early in the course of the procedure. Five of these patients died. This complication is rare but devastating, resulting from traumatic opening into large uterine sinuses, especially with the patient in the Trendelenburg position, when the heart is below the level of the uterus. Several steps can be taken to try to prevent this problem.

Transcervical endometrial resection

STUDY OBJECTIVES

To determine the safety and efficacy of endometrial resection, and to provide an indicator of the operative problems and treatment outcomes.

DESIGN

Prospective study.

SETTING

Academic practice tertiary care setting.

PATIENTS

One hundred twenty-six consecutive women undergoing endometrial resection because of menorrhagia, who wished to retain their uterus.

INTERVENTION

Hysteroscopic endometrial resection performed as a day procedure.

MEASUREMENTS AND MAIN RESULTS

In 126 women, 2 cases of uterine perforation were readily identified on the operating monitor screen; they had no serious sequelae. Three patients had heavy uterine bleeding, which was controlled by intrauterine tamponade. No women had other serious complications.

CONCLUSION

Hysteroscopic endometrial resection is a safe, successful, and cost-effective treatment of menorrhagia.

Complications of hysteroscopy-their cause, prevention, and correction

Complications of hysteroscopy occur more frequently in operative than in diagnostic cases. Problems related to uterine distention are common, usually preventable, and potentially extremely serious. Perforation of the uterus may occur during hysteroscopy but do not always cause significant problems. In procedures of high risk for perforation the use of mechanical energy is safer than either laser or electrical energy. Laparoscopy and ultrasonography have some limited use in facilitating operative hysteroscopic procedures. Most complications occur during the hysteroscopic surgical procedure. However, some problems may not be apparent until the post operative period.

Transcervical endometrial cryoablation (ECA) for menorrhagia

OBJECTIVE

To evaluate endometrial cryoablation (ECA) as a treatment for menorrhagia.

METHOD

Prospective study of 67 women. ECA uses the Joule Thompson principle of expanding gases. The ECA probe has a channel to inject saline solution into the uterine cavity. The probe is introduced into the uterine cavity, which is distended with 5 ml saline solution. The device is activated for two freeze-thaw cycles. The saline solution forms an ice mold of the uterine cavity which can be observed by ultrasound scan.

RESULTS

No surgical or long-term complications were observed. Two-thirds of patients followed up for > 3 months were completely satisfied.

CONCLUSIONS

ECA is technically very easy, can be learned quickly, is free of complications and led to improvement of menstrual symptoms in 63% of patients followed up for 3-18 months. The device is virtually maintenance-free and requires only a small initial investment, while running costs are negligible.