Role of imaging in predicting salvageability of kidneys in urinary tract tuberculosis.
OBJECTIVE
To study the role of imaging in predicting salvageability of kidneys and the role of early nephrectomy in urinary tract tuberculosis (TB).


METHODS
This was a retrospective study of 103 cases managed between 1990 to 1998. Intravenous urograms (IVUs) were reviewed and based on the IVU findings. Patients were stratified into three groups. Treatment consisted of immediate surgery, defined as nephrectomy within six weeks of starting anti-TB treatment (ATT) and delayed as nephrectomy done after completion of ATT. Chi square test was applied to find the significance of early nephrectomy. Logistic regression analysis model was used to identify factors predicting salvageabilty of the nephron mass.


RESULTS
Of the 103 cases, 23 had early nephrectomy and all of them achieved cure and had good renal function at follow up. Of the 76 who received only ATT, 43 were cured and the remaining 33 deteriorated symptomatically with high serum creatinine and decreasing GFR. Of the 33 who deteriorated, radiological and biochemical deterioration was seen in 24, two developed flank sinus and one developed multi drug resistant TB. On sub-grouping of the patients based on IVU, it was found that those with major renal lesion alone (group A) or with bladder involvement (group C) required either early or delayed nephrectomy and those who had minor lesion (group B) or bladder involvement with or without minor lesion (group C) did well on ATT alone. Logistic regression model showed cavitory lesions, GFR < 20ml/min/m2 and gross hydronephrosis as statistically significant unfavourable factors and ureteric stricture as a favourable factor.


CONCLUSIONS
In the era of modem ATT, nephrectomy is still an essential procedure. We recommend early nephrectomy for patients with major renal lesion with or without bladder involvement, gross hydronephrosis and for those who have GFR of < 20 ml/min/m2. Lower ureteric strictures and renal units with GFR of > 20 ml/min/m2 are favourable factors and salvage procedures are successful in these cases. It is likely that nephrectomy removes a large focus of disease and possibly dormant bacteria. With continuance of ATT, this further helps in improved patient outcome.
Viswaroop
Bobby
B
Department of Urology, Christian Medical College, Vellore-632 004.
Gopalakrishnan
Ganesh
G
Nath
Vishwambhar
V
Kekre
Nitin S
NS
D000995:Antitubercular Agents / Q000627:therapeutic use; D005260:Female; D006801:Humans; D007668:Kidney / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D009169:Mycobacterium tuberculosis / Q000187:drug effects; D009392:Nephrectomy; D011237:Predictive Value of Tests; D011859:Radiography; D012189:Retrospective Studies; D016879:Salvage Therapy; D014401:Tuberculosis, Urogenital / Q000000981:diagnostic imaging / Q000628:therapy*; D014463:Ultrasonography
D000995:Antitubercular Agents