Uterine Arteriovenous Malformation - A Rare Cause of Uterine Haemorrhage

UTERINE ARTERIOVENOUS MALFORMATION -A RARE CAUSE OF UTERINE HAEMORRHAGE
Abhang Prabhu*, Alka Gupta**, Shashank Parulekar***
*Former Registrar, Presently, Lecturer, N. Wadia Maternity Hospital;
***Associate Prof.; ***Prof.; Dept. of Ob and Gy, KEMH, Seth GS Medical College.

A uterine arteriovenous malformation is a rare cause of menorrhagia. However it is important to consider in the assessment of a patient with abnormal (especially heavy) uterine bleeding because accurate diagnosis can allow appropriate treatment to be planned and avoid hysterectomy in women who wish to retain their reproductive capacity. Until relatively recently this condition was difficult to diagnose and management almost always required hysterectomy. Special investigations (hysteroscopy, Doppler flow ultrasound and pelvic angiography) are important for diagnosis and assessment. We report a case of uterine arteriovenous malformation diagnosed and successfully treated with uterine embolization.
INTRODUCTION
A diversity of nomenclature is used to describe arteriovenous malformation cirsoid aneurysm, arteriovenous fistula, arteriovenous aneurysm, pulsating angioma, and cavernous angioma are commonly encountered terms. Arteriovenous malformation of the uterus and adnexa is a rare entity; its paucity is established in the gynaecologic literature. That does not detract, however, from diagnostic and therapeutic difficulties encountered by the gynaecologist faced with the serious problem of haemorrhage and its sequelae. Most reported cases have been treated by hysterectomy. Unlike with the more common causes of excessive uterine bleeding, curettage is not therapeutic and may aggravate the bleeding and hormonal therapy also almost always fails. [1] Clinical findings are unreliable, and in the past, diagnosis was usually made only at laparotomy or after examination of the hysterectomy specimen. This report highlights use of newer diagnostic modalities and conservative treatment with successful outcome in a case of uterine arteriovenous malformation.
CASE REPORT
25 year old, married, AAK, Gravida[1], Para 0, Abortus[1] presented with monorrhagia in out patient department of KEMH on July, 1997. Her menarche was at 15 years and since then she was having menorrhagia. Medical history included, spontaneous abortion followed by dilation and curettage in May, 1996. Menorrhagia had worsened 2 months after the curettage. For six months patient was given oestrogen and progesterone combinations but despite that she had heavy withdrawal bleedings. Many attempts were made to control the patient’s recurrent menorrhagia with various oestrogenprogestin combinations. On systemic examination there was no abnormality detected, pallor being prominent feature on general examination. Per abdomen and per speculum examination was normal. On internal examination uterus was bulky, retroverted, mobile, non pulsatile, fornices clear.

On investigation patient had Hb - 7.9 gm/%. Coagulation profile was within normal limits. In view of bulky uterus, transvaginal ultrasonography pelvis was done to rule out intrauterine pathology. Ultrasonography suggested features of uterine arteriovenous malformation on posterior wall of uterus. Uterine artery colour doppler revealed abnormal pulsation near the posterior intramural portion. Angiography of uterine vessels depicted vermiform pattern of opacification confirming a large uterine arteriovenous malformation receiving most of blood from right uterine artery.

After discussing all possibilities of treatment with patient, spring coil embolisation of bilateral uterine arteries was done with due informed consent. Post emoblisation angiography confirmed proper placement of spring coil. Post procedure course in ward was uneventful.

Patient was given hormonal treatment in the form of medroxy progesterone acetate from Day 15 - Day 25 for three cycles. Progesterone withdrawal bleeding was not heavy. Subsequently patient had normal menses without excessive bleeding or pelvic complaints. Patient is still asymptomatic one and half years after the embolisation and her last followup was in December 1998.
DISCUSSION
The first case of arteriovenous malformation was reported in 1926 by Dubreuil and Loubat. [2] An arteriovenous malformation consists of a proliferation of arterial and venous channels with fistula formation and an admixture of small capillary-like channels. In many cases, distinction between arteries and veins is blurred because of secondary intimal thickening in the latter as a result of elevated intraluminal pressure.

A review of literature showed that uterine arteriovenous malformation may be congenital or acquired. Acquired malformation may be due to previous uterine trauma (prior pelvic operation, curettages), intrauterine contraceptive devices, pathologic pregnancy-related events, and the treatment of gestational trophoblastic disease. [2] Our patient’s history of menorrhagia as an adolescent may indicate a congenital aetiology although trauma related to past curettage may have aggravated it.

Review of the 16 documented cases of primary uterine arteriovenous malformations shows that eight were associated with previous spontaneous abortions, including one patient who had a history of habitual abortion. Another patient had a history of three stillbirths associated with antepartum haemorrhage.

In our case clinical examination was unremarkable. The findings such as audible bruits and pulsatile masses felt at vaginal examination were absent. Bleeding was the major presenting symptom. Surprisingly our patient did not give history of profuse bleeding during or immediately after the post abortion curettage. Ideally in such cases bleeding presumably occurs when vessels erode through or about the endometrium, becoming exposed on shedding.

The case also highlights the role of investigational technology in the diagnosis. Diagnosis by uterine angiography is well documented in the literature. However this case is one of the few reported cases, diagnosed by transvaginal ultrasonography. [2] All cases were treated by total hysterectomy, and subsequent bleeding was not a problem. More recently, uterine arteriovenous malformations have been treated successfully by intra-arterial embolization. [3]

Embolization with particulate matter has been reported in various surgical haemorrhagic conditions. Particular substances for embolization used singly or in combination include autologous blood clot, Gelfoam microfibrillar collagen, polyvinyl, alcohol, isobutyl cyanocrylate, and Gianturco stainless steel coil spring occluders.[4]

The clinical significance of such arteriovenous shunting would be abnormal uterine bleeding and haemodynamic effect depending on the size of shunt. Bleeding may cause chronic anaemia or severe life threatening haemorrhagic shock. The possibility of an arteriovenous malformation of the uterus should be considered in cases of refractory bleeding. The potential hazards of curettage, parturition, and surgery in such cases must be evaluated carefully. Vascular embolization by angiography should be included in the armamentarium for managing severe uterine bleeding associated with an arteriovenous malformation.
ACKNOWLEDGEMENT
The authors are grateful to Dr. Mina Bhattacharya, Professor and Head, Dept of Obstetrics and Gynaecology, Seth GS Medical College and Dr. PM Pai, Dean, KEM Hospital for permission to publish hospital data.
REFERENCES

Markoff G, Quagliarello J, Rosen RJ, Beckman EM. Uterine arteriovenous malformation successfully embolized with a liquid polymer, isobutyl 20 Cyanoacrylate. Am J Obstet Gynecol 1986; 155 : 659-60.
Ghosh TK. Arteriovenous malformation of the uterus and pelvis. Obstet Gynecol 1986; 68 (suppl) : 40-3.
Poppe W, Van Assche FA, Wilms G, Favril A, Baert A. Pregnancy after transcatheter embolization of a uterine arteriovenous malformation. Am J Obstet Gynecol 1987; 156 : 1179-80.
Fleming H, Ostor AG, Pickel H, Forune DW. Arteriovenous malformations of the uterus. Obstet Gynecol Feb., 1989; 73 (2) : 209-14.

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