Overview.
Renal tuberculosis is a secondary infection caused by tubercle bacilli spreading from the lungs or other organs to the kidneys via the bloodstream. It is a part of systemic tuberculosis and often involves the kidneys, ureters, bladder and the reproductive system, and is collectively known as genitourinary tuberculosis. The disease starts slowly, with no obvious symptoms in the early stage, and in severe cases, intractable urinary tract irritation is the main clinical manifestation, which is rare in children, and there are more males than females, about 2:1.
Causes
The main primary lesion of renal tuberculosis is pulmonary tuberculosis, with a few tuberculous lesions from bones, joints, intestines and lymph nodes. Occasionally, it spreads from the genital tract to the kidneys. The average interval from pulmonary to renal tuberculosis is 8 years.
The most common pathogen in China is human-type Mycobacterium tuberculosis; other rare pathogens include bovine-type Mycobacterium tuberculosis and Mycobacterium undulatum.
Symptoms
Clinical symptoms can be relatively insidious, but more than half have a clear history of previous extrarenal tuberculosis infection, and less than 10% show active extrarenal lesions.
1. Urinary tract irritation
Urinary frequency is the earliest to appear, the first onset of urinary frequency may not be accompanied by urinary pain, progressive urinary frequency aggravation at the same time as the emergence of urinary urgency, urinary pain, urinary incontinence, urinary difficulties and nocturia can occur in severe cases, the application of general antibiotic treatment is ineffective.
2. Hematuria, pyuria
Tuberculosis of kidney, ureter or bladder can cause hematuria and pyuria. If it is caused by tuberculous ulcer in the bladder triangle, it is mostly hematuria at the end. Full bladder hematuria is seen in lesions above the bladder. There are large numbers of pus cells in the urine and sometimes necrotic tissue can be found. Severe patients may have “rice soup-like” urine.
3. Pain and swelling in kidney area
Low back pain is not obvious, but if the ureter is blocked, dull pain or colic may occur. In a few cases, a mass may be palpable due to renal pus or hydronephrosis.
4. Systemic symptoms
In severe cases or when there is tuberculosis in other organs, symptoms of tuberculosis poisoning such as emaciation, fatigue, hot flashes, night sweats and loss of appetite may appear. Chronic renal insufficiency, such as edema, anemia, oliguria or anuria, can be seen in patients with severe dysfunction of both kidneys.
Examination
1. Laboratory examination
Urine routine suggests obvious pyuria; blood sedimentation rate increases, urine common bacterial culture is negative, PPD (++) or more.
2.Imaging examination
(1) Ultrasound, suggesting hydronephrosis or cyst-like changes.
(2) Intravenous pyelogram (IVP) is one of the most important diagnostic tools, especially in the early stage, when the common worm-like changes have not yet appeared, but only show a slightly blunt and fuzzy calyx, which may suggest the presence of tuberculosis.
(3) CT is used when the first two examinations fail to confirm the diagnosis, and its diagnostic compliance rate is the highest, which can be more than 90%.
Diagnosis
Symptoms of urinary tract infection, after active antibiotic treatment is ineffective, urine culture shows tubercle bacilli, further combined with imaging, cystoscopy can be diagnosed. If there is a history of tuberculosis or close contact with tuberculosis, and those who have not been vaccinated with BCG vaccine can help to diagnose the disease, and the diagnosis can be confirmed by analyzing with the above clinical manifestations.
Treatment
1. Principles of treatment
As renal tuberculosis is a systemic disease, the following four principles must be emphasized in treatment:
(1) Treatment of primary foci That is, while treating renal tuberculosis, attention should also be paid to the condition of the primary foci causing renal tuberculosis.
(2) Supportive therapy Attention should be paid to strengthening nutrition and improving the immunity and tissue repair ability of the affected children.
（For children with severe and complicated renal tuberculosis, especially those with closed renal abscess, urinary tract obstruction that cannot be relieved by medical treatment, or severe bladder contracture, medical treatment should be combined with surgical treatment.
(4) Treatment of male cases Because men are prone to complications of tuberculosis of the reproductive system, the course of drug treatment for male patients is longer than that for women.
2. General treatment
Nutrition should be strengthened, living environment should be improved, appropriate rest, reasonable exercise, and a good attitude should be maintained.
3. Drug treatment
Regardless of whether surgical treatment is needed, sufficient, regular, complete and combined use of anti-tuberculosis drugs should be used to control the spread of tuberculosis. The use of drugs is guided by a precise bacteriologic diagnosis, often using a combination of rifampicin, isoniazid, ethambutol, or pyrazinamide for a 4- to 6-month period. A short course of therapy reduces treatment reactions (e.g., jaundice, loss of appetite, nausea, vomiting, and elevated transaminases). Urinary Mycobacterium tuberculosis culture test is required at the end of treatment, six months and one year later, and renal calcification images are followed up.
4. Surgery
Patients with indications for surgery should be given sufficient amount of anti-tuberculosis drugs before and after surgery, and nephrectomy, partial nephrectomy, or lesion removal surgery should be performed according to the situation.
(1) Surgical methods and indications ① Nephrectomy Total nephrectomy is suitable for patients with severe unilateral renal lesions without obvious damage on the opposite side or mild lesions with normal renal function. For severe renal lesions on one side with bladder contracture and contralateral pyelonephrosis and normal renal function, nephrectomy can still be performed first. If there is renal insufficiency, simple urinary drainage surgery can be performed first to normalize renal function, and then nephrectomy can be performed later. For lesions limited to a part of the kidney and communicating with the renal pelvis, most of them can be cured by drug treatment, and very few cases only need partial nephrectomy. ② Removal of renal lesions For closed abscess cavities in renal tuberculosis, which is now being treated by ultrasound-guided local puncture aspiration or drug instillation instead. ③ Correction of upper urinary tract obstruction If the obstruction still persists after chemotherapy, pyeloplasty or ureteral reimplantation, etc. are feasible. Surgical treatment of bladder contracture: Bowel, cecum or colon cystoplasty is feasible for severe bladder contracture. ⑤ End-stage renal failure caused by double renal tuberculosis, blood purification or renal transplantation.
(2) Contraindications to surgery ①Severe lesions of both kidneys. ② Poor general condition, or extra-renal tuberculosis still in the progressive stage. ③ Unilateral renal tuberculosis can be cured by chemotherapy.
Prognosis
Prognosis is determined by the following factors: ① general condition and tuberculosis outside the urinary tract. ② The severity of tuberculosis lesions in the bladder. The severity of tuberculosis of the bladder. ③ The disease and function of the opposite side of the kidneys. The timing and correctness of treatment.
Most of the cases can be cured by drug treatment, and the prognosis of unilateral lesions is better, but it is still not optimistic due to the increase of drug-resistant Mycobacterium tuberculosis infection year by year. In recent years, the total morbidity and mortality rate has been reported to be 2% to 50%.
Prevention
1. BCG vaccination: BCG vaccination for uninfected tuberculosis patients is the fundamental measure to prevent tuberculosis.
2. Active treatment to prevent spreading.
3. Strengthen nutrition and avoid overwork.