HYSTEROSCOPY and transcervical resection of uterine diseases are popular and well-accepted diagnostic and therapeutic procedures. Complications include cervical laceration, uterine perforation, and absorption of hysteroscopic fluid. However, the incidence of these complications is low (< 5%).
We describe the treatment of a patient undergoing hysteroscopy and transcervical resection of a large, type I myoma, in whom the symptoms of intraabdominal hemorrhage from an unrecognized uterine perforation were masked by volume uptake, which caused hemodilution and hyponatremia.
A 56-yr-old healthy woman (162 cm, 54 kg) presented to the gynecologic unit for hysteroscopy and transcervical endoscopic myoma resection because of abnormal uterine bleeding as a result of a posterior submucous uterine type I myoma. Spinal anesthesia resulted in a T4 sensory block, which was assessed by the absence of cold discrimination. There was no significant change in blood pressure or heart rate. For hysteroscopy, commercial equipment was used, which consisted of a piston pump that allowed for infusion pressure control of low-viscosity fluids in a continuous-flow hysteroscopic system. The distending medium was an electrolyte-free mixture of 27 g/l sorbitol and 5.4 g/l mannitol (osmolality, 178 osmol/l; pH, 4.5–7). After a hysteroscopy time of approximately 60 min, shortly before the end of the procedure, the patient suddenly became hypotensive (70/40 mmHg), and bradycardia developed (43 beats/min). The patient remained alert and oriented. No change in oxygen saturation was observed. Vital signs improved quickly with use of an intravenous fluid bolus of lactated Ringer’s solution, supplemented by 20 mg intravenous ephedrine and 1 mg intravenous atropine. The patient was administered perioperatively 1,700 ml lactated Ringer’s solution and 500 ml hydroxyethyl starch, 6%. During the 70-min operation, approximately 800 ml of a total of 3,500 ml irrigating fluid was unaccounted for and was considered to have been intravascularly absorbed. Results of laboratory testingwere consistent with dilutional hyponatremia (125 vs. 143 mm preoperatively) and anemia (91 vs. 153 g/l preoperatively).
The surgical procedure was discontinued, and the patient was immediately transferred to the postoperative care unit. Intravenous furosemide (20 mg) was administered to enhance diuresis. A few minutes later, hypotension with a systolic blood pressure of 60 mmHg reoccurred, although no vaginal bleeding was apparent. Administration of 500 ml hydroxyethyl starch, 6%, and repetitive 10-mg boluses of intravenous ephedrine were administered. After blood pressure restoration, generalized convulsions developed that lasted for 2 min and resolved without pharmacologic intervention (127 mm serum sodium; 69 g/l hemoglobin). Neither airway nor oxygen saturation were compromised.
During the next 60 min, the patient experienced progressively increased dull abdominal pain; sonographic imaging revealed intraabdominal fluid, measuring not more than 200 ml. The hemoglobin concentration decreased to 64 g/l, accompanied by slight coagulopathy (international normalized ratio, 1.5). A packed erythrocyte transfusion was initiated, and the patient was transferred to the operating room for emergency laparotomy. General anesthesia was rapidly induced with use of etomidate and fentanyl and tracheal intubation was facilitated with use of succinylcholine; induction was uneventful. When the peritoneum was open, approximately 3,000 ml blood was evacuated. A tear in the right internal iliac vein was repaired. Although no obvious uterine perforation was found, there were two necrotic areas, both measuring 5 mm in diameter, on the posterior uterine wall. During surgical repair, seven packed erythrocyte concentrates and 4 units of fresh frozen plasma were administered, which resulted in a hemoglobin concentration of 91 g/l and an international normalized ratio of 1.3. Postoperative course was uneventful, and the patient was discharged from the hospital in good medical condition on the tenth postoperative day.
Absorption of irrigating solutions, resulting in fluid overload, is a well-known and severe complication of ablative hysteroscopy; the incidence rate is from 3 to 6%. Vascular uptake of irrigating fluid depends on a variety of factors. Surgical skills and the nature of the operation are considered to be key factors. Fluid absorption correlates with the surface area of the surgical field, opened venous channels, duration of the procedure, chemophysical characteristics of the distending medium, and pressure produced by the delivery system. Because rapid absorption of irrigation fluids during operative hysteroscopy cannot be completely prevented, careful perioperative monitoring of hysteroscopic fluid management is paramount, and abnormalities of fluid balance must be treated.
An awake patient may be the best monitor for early detection of excessive fluid absorption. Therefore, regional anesthesia offers a distinct advantage over general anesthesia. When early signs (i.e. , apprehension, disorientation, nausea, and visual disturbances) of excessive fluid absorption are suspected, interruption of the procedure must be considered. The safety of the patient should never be jeopardized, and steps should be taken to reduce the risk of fluid overload.
Uterine perforation is the most frequent complication of hysteroscopy (14.2 occurrences of 1,000 cases) and usually does not necessitate intervention. In our case, however, two areas of thermal necrosis of the posterior uterine wall were detected during laparotomy. We hypothesize that the tear in the internal iliac vein may have occurred as a result of direct laceration of the resectoscope or indirect thermal injury, causing transmural uterine necrosis; this has not been reported previously in scientific literature. The tear then triggered significant intraperitoneal bleeding. Acute anemia was thought initially to be caused by intravascular volume overload with hypoosmotic fluid, which caused hyponatremic hemodilution, and not by blood loss. Our hypothesis was consistent with the clinical symptoms of our patient. Only the onset of hemodynamic instability in combination with increased abdominal pain led to the correct diagnosis.
Our case clearly shows that minimally invasive surgery, such as hysteroscopy, may also include the risk of massive occult bleeding, and, therefore, careful monitoring of the patient during and after the procedure is warranted.
The authors thank Mrs. Joan Etlinger, Department of Anesthesia, University of Basel, Kantonsspital, Basel, Switzerland, and Kere Frey, D.O., Assistant Professor of Anesthesia, Department of Anesthesia, Kantonsspital, Luzerne, Switzerland, for their assistance with the manuscript.