Hysterosalpingography and

Other Interventional Procedures

The hysterosalpingogram (HSG) primarily demonstrates the uterus and uterine (fallopian) tubes of the female reproductive system.

Anatomic considerations for hysterosalpingography include the principal organs of the female reproductive system, including the vagina, uterus, uterine tubes, and ovaries.

The uterus is the central organ of the female pelvis. It is a pear-shaped, hollow, muscular organ that is bordered posteriorly by the rectosigmoid colon and anteriorly by the urinary bladder The size and shape of the uterus vary, depending on the patient's age and reproductive history. The uterus is positioned most commonly in the midline of the pelvis in an anteflexed position supported chiefly by the various ligaments. The position may vary with bladder or rectosigmoid distention, age, and posture.

The uterus is subdivided into four divisions: (1) the fundus, (2) the corpus (body), (3) the isthmus, and (4) the cervix (neck) The fundus is the rounded, superior portion of the uterus. The corpus (body) is the larger central component of the uterine tissue. The narrow, constricted segment, often described as the lower uterine segment that joins the cervix at the internal os, is the isthmus. The cervix is the distal cylindrical portion that projects into the vagina, ending as the external os.The uterus is composed of inner, middle, and outer layers. The inner lining is the endometrium, which lines the uterine cavity and undergoes cyclic changes in correspondence to the woman's menstrual cycle. The middle layer, the myometrium, consists of smooth muscle and constitutes the majority of the uterine tissue. The outer surface of the uterus, the serosa, is lined with peritoneum and forms a capsule around the uterus.

Uterine tubes: The uterine (fallopian) tubes communicate with the uterine cavity from a superior lateral aspect between the body and the fundus. This region of the uterus is referred to as the cornu. The uterine tubes are approximately 10 to 12 centimeters in length and 1 to 4 millimeters in diameter. They are subdivided into four segments. The proximal portion of the tube, the interstitial segment, communicates with the uterine cavity. The isthmus is the constricted portion of the tube, where it widens into the central segment termed the ampulla, which arches over the bilateral ovaries. The most distal end, the infundibulum, contains fingerlike extensions termed fimbriae, one of which is attached to each ovary. The ovum passes through this ovarian fimbria into the uterine tube, where—if it is fertilized—it then passes into the uterus for implantation and development.

The distal infundibulum portion of the uterine tubes containing the fimbriae opens into the peritoneal cavity

Purpose

Hysterosalpingography is the radiographic demonstration of the female reproductive tract with a contrast medium. The radiographic procedure best demonstrates the uterine cavity and the patency (degree of openness) of the uterine tubes. The uterine cavity is outlined by injection of contrast medium throughout the cervix. The shape and contour of the uterine cavity are assessed to detect any uterine pathologic process. As the contrast agent fills the uterine cavity, the patency of the uterine tubes can be demonstrated as the contrast flows through the tubes and spills into the peritoneal cavity.

Pathologic Indications

Infertility assessment: One of the most common indications for HSG is seen in the assessment of female infertility. The procedure is performed to diagnose any functional or structural defects. A blockage of one or both uterine tubes may inhibit fertilization. In some cases, HSG can be a therapeutic tool. Injection of contrast media may dilate or straighten a narrowed, tortuous, or occluded uterine tube

Contraindications

Hysterosalpingography is contraindicated with pregnancy. To avoid the possibility that the patient may be pregnant, the examination typically is performed 7 to 10 days after the onset of menstruation.Other contraindications include acute pelvic inflammatory disease and active uterine bleeding.

Patient Preparation

Departmental protocol should determine patient preparation requirements. These procedures may include proper bowel preparations to ensure adequate visualization of the reproductive tract unobstructed by bowel gas and/or feces. Preparation may include a mild laxative, suppositories, and/or a cleansing enema before the procedure. In addition, the patient may be instructed to take a mild pain reliever before the examination to alleviate some of the discomfort associated with cramping.To prevent displacement of the uterus and uterine tubes, the patient should be instructed to empty her bladder immediately before the examination.The procedure and possible complications should be explained to the patient and informed consent obtained. In some instances, the physician also may perform a manual pelvic examination before the radiographic procedure is begun.

Major EquipmentThe major equipment required for an HSG is a radiographic fluoroscope room. Newer equipment may provide digital fluoroscopy capabilities. Ideally, the table should have the capability to tilt the patient to a Trendelenburg position if needed. If available, gynecologic stirrups should be attached to the table to assist the patient in the lithotomy position.

Accessory and Optional EquipmentRoutinely, a sterile, disposable HSG tray is used The general contents of the tray include a vaginal speculum, basin, cotton balls, medicine cup, sterile gauze, sterile drapes, sponge-holding forceps, 10 ml syringes, 16 and 18 gauge needles, extension tubing, and lubricating jelly. In addition to the HSG tray, sterile gloves, an antiseptic solution, a cannula or balloon catheter, and contrast media are necessary.

Contrast Media

Two categories of radiopaque (positive) iodinated contrast media have been used in HSG. Water-soluble iodinated contrast media, such as Omnipaque 300, is preferred. It is absorbed easily by the patient, does not leave a residue within the reproductive tract, and provides adequate visualization. This medium does, however, cause pain when injected within the uterine cavity, and the pain may persist for several hours after the procedure.In the past, oil-based contrast media that allowed for maximal visualization of uterine structures was used. However, it has a very slow absorption rate and persists in the body cavities for an extended time. It also introduces the risk that an oil embolus that could reach the lungs may form.The amount of contrast medium to be introduced into the reproductive tract is variable, depending on radiologist preference. On average, approximately 5 ml is necessary to fill the uterine cavity, and an additional 5 ml is needed to demonstrate uterine tube patency. Fractional injections may be performed during the study.

Cannula/Catheter Placement and Injection ProcessAt the beginning of the procedure, the patient lies supine on the table in the lithotomy position. If gynecologic stirrups are unavailable, the patient bends her knees and places her feet at the end of the table. The patient is draped with sterile towels, and with sterile technique, a vaginal speculum is inserted into the vagina. The vaginal walls and cervix are cleansed with an antiseptic solution. A cannula or balloon catheter then is inserted into the cervical canal. Dilation with a balloon catheter helps to occlude the cervix, preventing contrast medium from flowing out of the uterine cavity during the injection phase. Once cervical placement of the cannula or catheter has been obtained, the physician may remove the speculum and place the patient in a slight Trendelenburg position. This position facilitates the flow of contrast media into the uterine cavity. A syringe filled with contrast is attached to the cannula or balloon catheter. Using fluoroscopy, the physician slowly injects contrast medium into the uterine cavity. If the uterine tubes are patent (open), contrast media will flow from the distal ends of the tubes into the peritoneal cavity.

RADIOGRAPHIC ROUTINESRoutine positioning for hysterosalpingography varies with the method of examination. Fluoroscopy, conventional radiography, or a combination of both may be used.

FLUOROSCOPY/SPOT FILMING OR DIGITAL FLUOROSCOPY/IMAGING

Imaging of the reproductive tract is most commonly acquired with the use of spot-film fluoroscopy or, more recently, digital fluoroscopy. Typically, a collimated scout image is obtained with fluoroscopy. During injection of the contrast medium, a series of collimated images may be taken while the uterine cavity and uterine tubes are filling After injection of the contrast medium, an additional image may be taken to document spillage of the contrast into the peritoneum The patient most commonly remains in the supine position during imaging, but additional images may be taken with the patient in an LPO or RPO position to adequately visualize pertinent anatomy

RADIOGRAPHY

An overhead AP scout image may be obtained on a 24 × 30-centimeter (10 × 12-inch) IR. The central ray and IR are centered to a point 2 inches (5 cm) superior to the symphysis pubis. If fluoroscopy is unavailable, fractional injection of contrast medium is implemented, with a radiograph performed after each fraction to document filling of the uterine cavity, the uterine tubes, and contrast medium within the peritoneum. Additional images as determined by the radiologist may include LPO or RPO positions.

RADIOGRAPHIC CRITERIA

• The pelvic ring as seen on an AP projection should be centered within the collimation field. • The cannula or balloon catheter should be demonstrated within the cervix. • An opacified uterine cavity and uterine tubes are demonstrated centered to the IR. • Contrast medium is seen within the peritoneum if one or both uterine tubes are patent. • Appropriate density and short-scale contrast demonstrate anatomy and contrast medium. • The patient ID marker should be clear, and the R or L marker should be visualized without superimposition of anatomy

Scout

Other Interventional Procedures

Interventional imaging procedures are radiologic procedures that intervene in a disease process, providing a therapeutic outcome. Simply stated, interventional procedures use angiographic techniques for the treatment of disease, in addition to providing certain diagnostic information.This is a rapidly growing specialty in medical imaging as interventional procedures have become an increasingly important tool in the management of an ever-growing list of pathologies.

The purpose of these procedures and benefits to the patient and health care system include the following: •Techniques that are minimally invasive with lower risk compared with traditional surgical procedures•Procedures that are less expensive than traditional medical and surgical procedures•Shorter hospital stays for the patient•Shorter recovery time because of a safer, less invasive procedure•Alternatives for patients who are not candidates for surgery

These procedures typically are performed in an angiographic suite under the direction of an interventional radiologist. Fluoroscopic guidance is crucial to follow the path of the required needles and catheters.

The increase in complexity of the type of interventional procedures currently performed has resulted in the upgrading of many angiography units to meet operating room specifications. This reduces the risk for infection and allows rapid surgical management in case of complications.

Interventional procedures may be categorized as vascular or nonvascular procedures

VASCULAR INTERVENTIONAL PROCEDURES

Embolization

Transcatheter embolization is a procedure that uses an angiographic approach to create an embolus in a vessel, thus restricting blood flow. A number of clinical indications for this procedure exist, including the following:

•Stop blood blow to a site of pathology.•Reduce blood flow to a highly vascular structure and tumor before surgery.•Stop active bleeding at a specific site.•Deliver a chemotherapeutic agent

Uterine fibroid embolizationThis procedure is used to treat symptomatic fibroids. Embolization of the uterine artery can shrink the fibroids and eliminate associated pain and bleeding, thus replacing a hysterectomy.

Uterine artery embolizationThe uterine artery also may be embolized to stop life-threatening postpartum bleeding, potentially preventing hysterectomy.

ChemoembolizationThis is used most commonly for hepatic malignancies. The chemotherapy agent is injected into the tumor vasculature. The survival rate from this procedure is comparable with that following treatment by a more invasive surgical resection. Investigation is under way regarding the use of this technique for other locally advanced cancers (e.g., lung, breast, brain).

Angioplasty

Percutaneous transluminal angioplasty (PTA) uses an angiographic approach and specialized catheters to dilate a stenosed vessel. This procedure is a long-standing interventional technique that has applications for a wide variety of vessel types and sizes (e.g., coronary, iliac, renal arteries).A catheter with a deflated balloon is advanced to the vessel of interest. Hemodynamic pressures proximal and distal to the stenosis are obtained, and a preangioplasty angiogram is performed. The balloon portion of the catheter is placed at the vessel stenosis, and the balloon is inflated. The pressure of the inflation is monitored by a pressure gauge to prevent vessel rupture, and more than one inflation may be required. The duration of the inflations is carefully timed to eliminate damage to distal tissue because the blood supply is temporarily occluded.Final steps of the procedure include obtaining arterial pressures proximal and distal to the dilated portion of the vessel and performing a post-angioplasty angiogram. This allows assessment of the effectiveness of the procedure.

Stent placement

To assist in maintaining patency of the vessel, a stent is inserted across the treated area during the angioplasty. A stent is a cagelike metal device that is placed in the lumen of a vessel to provide support. It can be a self-expanding type or a balloon-expandable type. The self-expanding type automatically expands when the stent cover is removed from the vessel, and the balloon-expandable type (the compressed stent covers the balloon on the catheter) is positioned during the balloon inflation phase of the angioplasty. Currently, many stents are impregnated with a pharmacologic agent that inhibits the regrowth of vascular tissue within the artery and interferes with the process of restenosis.

An inferior vena cava filter is indicated for patients who have recurrent pulmonary emboli or who are at high risk for developing them (e.g., post trauma with pelvic and lower extremity fractures). A filter is placed in the inferior vena cava to trap potentially fatal emboli that originate in the lower limbs. A variety of filter designs are available for this procedure andA femoral or jugular vein puncture is used to gain access to the inferior vena cava. An angiographic technique then is used to deploy the filter by a catheter. The filter has struts that anchor it to the walls of the vessel. The filter must be placed inferior to the renal veins to prevent renal vein thrombosis.Risks and complicationsBesides the usual angiographic complications (e.g., infection, bleeding), the added risk that the filter may migrate into the heart and lungs exists. The filter also may become occluded in the long term.

NONVASCULAR INTERVENTIONAL PROCEDURES

Vertebroplasty

Percutaneous vertebroplasty is used to treat patients who have vertebral pain and instability caused by osteoporosis, spinal metastases, compression fractures, or vertebral angiomas. Percutaneous injection of acrylic cement into the vertebral body under fluoroscopic guidance contributes to stabilization of the spine and long-term pain relief.This procedure is performed in the OR or in the interventional suite. The surgeon will place a small hollow needle through the patient's back until it reaches the affected area of the vertebrae. Once the needle is in place and this has been verified by C-arm fluoroscopy (PA and lateral views), the surgeon injects an orthopedic cement mixture that also may include contrast (for better visibility on the monitor). The surgeon usually will ask for continuous fluoro while the cement mixture is being injected. At this point, the surgeon checks to ensure that the cement has filled the entire affected vertebral area and withdraws the needle. The orthopedic cement hardens quickly and stabilizes the fractured vertebrae, which results in pain relief.

Kyphoplasty

The vertebroplasty technique has been modified recently, resulting in a procedure known as kyphoplasty. Through small incisions, a kyphoplasty balloon is inserted into a collapsed vertebral body. The balloon is inflated for the purpose of restoring the collapsed portion of the vertebrae Acrylic cement then is injected to stabilize the vertebrae.

Risks and complicationsComplications of vertebroplasty include leakage of the cement into adjacent structures, which may require emergency surgery. A less common complication is pulmonary embolus, which causes migration of the cement into perivertebral veins.Complications associated with kyphoplasty are less than with vertebroplasty because less cement is required and it is injected in a more controlled fashion.