In surgery the name sinus is given to a 'long narrow, suppurating canal,' and fisiula to such a canal when it communicates with a mucous, synovial or serous cavity. An unnatural direct communication between two adjacent mucous surfaces is also called a fistula.<Callout type="important" title="Important">The diagnosis of a sinus is established by the passage of a probe along it, but the size and character of its aperture, the induration of its wall, and the amount of discharge which flows from it, or the special means by which that discharge can be made to flow, are other signs by which a sinus can generally be recognized.</Callout> A sinus being recognized, the surgeon must first decide whether it is a fistula by noticing the character of the discharge, and also whether a probe passed along it enters a mucous synovial, or serous cavity.<Callout type="risk" title="Risk">Fistulas can be dangerous if left untreated as they may lead to chronic infections.</Callout> Recto-vesical fistula is recognized by the passage of faeces and mucus with urine, and sometimes by the escape of urine from the bowel. Recto-vaginal and vesico-vaginal fistulae are diagnosed by the passage of faeces or urine from the vagina, and also by 'direct inspection of the part: where urine dribbles continually into the vagina the fistula opens into the bladder; where it only flows into the vagina during micturition the fistula opens into the urethra beyond the internal sphincter.<Callout type="tip" title="Tip">Always perform a thorough examination to identify any foreign bodies or exposed bone within the sinus.</Callout> In cases of doubt or difficulty, the sinus should be filled with Beck's paste (bismuth carbonate 1 part, glycerin 2 parts), injected under some pressure, and a skiagram of the part be taken; the track of the sinus and its relation to bones, joints, and serous cavities can thus be demonstrated.<Callout type="warning" title="Warning">Necrosis and caries are very common causes and accompaniments of sinus. In necrosis the exposed bone is felt to be firm, often smooth, and it gives a clear sound on being tapped.</Callout> If neither of these causes for the sinus is found, the surgeon must see whether the cavity drains efficiently, as retention of discharge is a very common cause of non-healing; in other cases he will find the sinus runs between muscles or other structures which are constantly being moved with any movement of the part.<Callout type="important" title="Important">Persistence of a sinus may possibly be due to any of the above causes, or alone associated with any of the superficial parts of a chronic inflammatory process due either to actinomyces and streptococcus.</Callout>
Key Takeaways
- Diagnosis of sinus involves probing the canal, examining its aperture, wall induration, discharge, and special means to induce flow.
- Recto-vesical fistula can be identified by faeces and mucus in urine or bowel leakage.
- Thorough examination is crucial for identifying foreign bodies and exposed bone within a sinus.
Practical Tips
- Always use Beck's paste when diagnosing difficult cases to visualize the track of the sinus.
- Perform direct inspection for recto-vaginal and vesico-vaginal fistulas to determine their exact location.
- Look for signs of necrosis or caries in the bone around a sinus, as these can indicate underlying causes.
Warnings & Risks
- Fistulas can lead to chronic infections if left untreated, so prompt diagnosis and treatment are critical.
- Necrosis and caries must be carefully distinguished from other causes of sinus to ensure proper treatment.
- Persistence of a sinus may not always have an obvious cause, requiring careful examination.
Modern Application
While the techniques described in this chapter are historical, the principles of thorough diagnosis and identifying underlying causes still apply. Modern imaging and diagnostic tools can enhance these methods, but understanding the basics remains crucial for emergency preparedness.
Frequently Asked Questions
Q: How is a sinus diagnosed according to this manual?
A sinus is diagnosed by probing it, examining its aperture, wall induration, discharge characteristics, and using special means to induce flow. Beck's paste can also be used for difficult cases.
Q: What are the signs of necrosis in a sinus?
Necrosis is indicated when the exposed bone feels firm, smooth, and gives a clear sound on tapping. However, these signs may not always be observed in typical cases.
Q: How can one differentiate between recto-vesical and vesico-vaginal fistulas?
Recto-vesical fistula is recognized by the passage of faeces and mucus with urine or bowel leakage, while vesico-vaginal fistula is diagnosed by the passage of urine from the vagina during urination.