Introduction
Abnormal uterine bleeding in perimenopusal and postmenopausal women is associated with endometrial carcinoma in approximately 10%.1 In 1980’s Endometrial Pipelle was introduced as an outpatient device to obtain an endometrial biopsy.2 It is a thin plastic suction tube, 3mm in diameter, with graduated markings designed to create a high vacuum without vacuum pump. The Pipelle will pass through the cervical canal to the uterine cavity and endometrium to obtain a sample for histological analysis. It is mainly used in women with abnormal uterine bleeding who are mainly from perimenopausal or postmenopausal age group.3 It is also suitable for women under 40 years of age with very low risk of developing endometrial carcinoma, further investigation may be needed in high risk symptomatic women i.e. It is appropriate for those at relatively low risk of carcinoma.4
The procedure
The procedure is easy to perform, the steps may include: obtaining verbal consent, then speculum being passed, cervix being visualised with a good light source and the Pipelle gently being passed through the cervical canal and held between finger and thumb. Then advance the Pipelle gently until it reaches the uterine fundus and withdraw the inner plunger. The Pipelle should be moved back and forth in the cavity and rotated to obtain tissue from 360 degrees of the endometrial wall. The patient should be informed that she may experience mild cramp abdominal pain with some vaginal spotting for a short time after the procedure. The vulsellum may be used to grasp the anterior lip of the cervix and straighten the canal if Pipelle does not pass easily.4
Advantages
With the Pipelle, it takes only a few minutes to perform the procedure, it is most convenient, and is best tolerated, causing less pain. It is the least expensive; one Pipelle sampler may cost less than ten pounds.5 It is conducted in outpatient setting to obtain endometrial tissue, not requiring hospitalisation, anaesthesia or cervical dilatation. It is an excellent method for screening and diagnostic purposes and has a high degree of sensitivity and specificity for the detection of endometrial carcinoma.6 The detection rates for endometrial carcinoma using the Pipelle device were found by one meta-analysis of 39 studies involving 7914 women (2000) to be 99.6% in postmenopausal women and 91% in premenopausal women.7 In addition, in postmenopausal women, the combined use of Pipelle sampling and ultrasound has a high detection rate for endometrial carcinoma.8 Since abnormal vaginal bleeding is a common problem with both general practice and the Pipelle, by being an office technique, using the latter allows general practitioners early diagnosis of endometrial cancer and reassurance for women without serious pathology.9
Disadvantages
The disadvantages of the Pipelle may include the procedure itself being uncomfortable or even painful, especially in nulliparous women, and insertion failure, which is high in this group. By being a blind procedure, it can miss focal lesions in the uterine cavity, such as polyp and sub mucous fibroid, and inadequate sampling may be obtained, particularly in post menopausal women with thin endometrium. However, since the ability to obtain adequate endometrial sampling is mainly affected by the endometrial thickness e.g. with endometrial thickness 10 and little can be gained from thin endometrium, it is accepted that the risk of malignancy in postmenopausal women with thin endometrium is rare.7 There is no therapeutic benefit with Pipelle compared to D&C i.e. Pipelle is mainly used for diagnostic purposes. Prophylactic antibiotics are not necessary during endometrial sampling for the prevention of infection or bacterial endocarditis.11 The Pipelle has very low risk of perforation compared with other devices for obtaining endometrial sampling; a case has been reported in a perimenopasal patient,12 showing the risk as 0.1 to 0.2% versus 0.3 to 2.6% from D&C.11
The Pipelle is absolutely contraindicated when pregnancy is suspected.11 The procedure may also not be advisable in the presence of acute vaginal or cervical infection, pelvic inflammatory disease and in patients with clotting disorders.
Efficacy of the Pipelle
Several studies have been carried out to assess the accuracy of the endometrial sampling for detection of endometrial tumours.
At Montefiore Medical Center in New York, between 1995 and 2005, a study conducted on 360 patients diagnosed with endometrial cancer evaluated the ability of preoperative endometrial sampling to diagnose high grade endometrial tumours accurately. The sensitivity for the detection of malignancy by the Pipelle was 93.8% in patients with low grade cancer and 99.2% in those with high grade cancer. When using curettage, the sensitivity of detection of malignancy was 97% in patients with low grade cancer and 100% in those with high grade cancer.13
In Magee-Women’s Hospital, USA, a study carried out in 1995 on 65 patients with known endometrial cancer, showed that the Pipelle biopsy was able to detect endometrial cancer in 54 patients out of 65. The study concludes that the Pipelle endometrial suction is an effective office device for evaluating patients, however, tumours localised to a polyp or small area of endometrium may go undetected.14
In 2004, the Department of Obstetrics and Gynaecology, School of Medicine, Zonguldak Karaelmas University, Turkey, carried out research to determine the reliability and accuracy of the Pipelle device in acquiring an adequate endometrial sample and compare it with D&C histology. A total of 127 women were prospectively included in the study. After the Pipelle endometrial sampling, D&C was performed on the same patients. The result was that samples for 29 of the patients in the Pipelle group were insufficient compared to 13 patients in D&C group. However, in 100 of the 127 patients (79%), the Pipelle endometrial biopsy result were the same as the D&C histology results, but the Pipelle biopsy was unable to diagnose one of the five endometrial hyperplasia. The study concluded that the Pipelle device is a limited endometrial sampling technique for obtaining an adequate and representative endometrial sample. It should be reserved for those patients in whom there is only a minimal risk for endometrial carcinoma, hyperplasia and polyps. Any failure to obtain an endometrial specimen would suggest performing a full endometrial curettage is adviseable, especially in high risk patients for endometrial cancer.6
In Lahor between January and December 2004, a study was carried out on 100 patients with abnormal uterine bleeding to assess the efficacy of the Pipelle as a tool for endometrial biopsy. These patients were scheduled for hysterectomies and they had endometrial sampling with the Pipelle before the surgery. Among 100 patients, 66 underwent hysterectomies. The finding of the final histopathologies were compared with those of the Pipelle. Of the remaining, six had inadequate specimens, and 28 were postponed for medical reasons. In 61 out of 66 patients, the histology results were identical (correlation of 92.4%), and five results were different. The Pipelle was unable to detect one case of endometrial cancer, and labeled it as complex hyperplasia due to the focal nature of malignancy, or the tumour present in an endometrial polyp. The sensitivity of the Pipelle in diagnosing endometrial cancer is 75%, and the specifcity is 100%. The conclusion was that Pipelle biopsy is useful, and it can reduce the number of D&C performed in the operation theater. However, hysteroscopy examinations of high risk patients is emphasised, as certain lesions in the endometrium can be missed wi