Map of the fistula tract before surgery
Chronic paraproctitis with fistula requires surgery, and its success is determined by how accurately the surgeon understands the anatomy of the tract. The fistula may pass over, through or below the sphincter, have lateral branches and blind spots, and the secondary opening in the skin is often located far from the true internal opening in the intestine. Operating blindly means either not removing the entire stroke and getting a relapse, or cutting too much muscle and getting incontinence.
Ultrasound with an intracavitary sensor builds an actual map: shows the internal opening, direction and level of movement relative to the external and internal sphincters, detects branches and purulent leaks in the ischiorectal and pelviorectal spaces. The introduction of hydrogen peroxide into the outer hole makes the stroke contrasting and clearly visible.
The same method is used in acute paraproctitis to determine the location and volume of the abscess, in the epithelial coccygeal tract, in assessing the integrity of the sphincters after birth injuries and operations, as well as in the staging of rectal tumors, where ultrasound shows the depth of wall invasion and the condition of the pararectal lymph nodes.
Ultrasound capabilities
Ultrasound remains the first choice for imaging in almost every situation: it is accessible, safe, does not require radiation, and provides images in real time. It perfectly shows parenchymal organs, fluid formations, walls of hollow organs and soft tissues, and in Doppler mode, blood flow in the vessels.
A separate advantage is the possibility of dynamic tests: the doctor can ask you to strain, change your body position, fill or empty an organ and see how the picture changes. Neither computed tomography nor magnetic resonance imaging provide such an opportunity.
What influences the quality of research
The main enemy of ultrasound is gas: it completely reflects the wave. Therefore, distended intestines can make the pancreas, aorta, and retroperitoneal structures invisible. For the same reason, preparation for examining the abdominal cavity is not a formality, but a condition for a reliable result.
Severe obesity, postoperative scars, bandages and open wounds in the area of interest also have an effect. If the picture turns out to be uninformative, the doctor indicates this in the protocol and recommends an alternative method - computed tomography or magnetic resonance imaging.
Doppler mode
Dopplerography shows the movement of blood: color mapping reflects the direction of flow, spectral analysis measures velocities and resistance indices. This allows you to assess the patency of the vessel, identify stenosis, thrombus, aneurysm, pathological reflux and the nature of the blood supply to the formation.
Increased blood flow in Doppler mode is an important sign of active inflammation or tumor growth, which is why many organ studies are supplemented with Doppler as a mandatory part of the protocol.