Purpose: Previous ultrastructural and clinical studies have established criteria for distinctive ultrastructural patterns in the normal, overactive, hypocontractile and obstructed detrusor of the elderly. This study was conducted to standardize procedures of detrusor biopsy processing, identify and address pitfalls and difficulties in applying the criteria to routine evaluation of biopsies in the surgical pathology laboratory, verify reproducibility of ultrastructural observations and diagnosis in biopsies from different sites in the bladder wall, and develop a standard approach to routine ultrastructural evaluation of the biopsy.
Materials and methods: Blinded to clinical information, 25 randomly selected detrusor biopsies were evaluated by a pathologist with prior knowledge of electron microscopy but none of detrusor ultrastructure. The observations and diagnoses made were subsequently correlated with urodynamic bladder behavior evaluated comprehensively before biopsy. Biopsies from different sites of 4 detrusors and specimen samples of multiple sites from a bladder obtained at autopsy were also blindly assessed to determine the reproducibility of single site biopsies.
Results: Essential parameters of all criteria were verified. Potential pitfalls and sources of difficulty in some were identified and corrected to refine the criteria. Diagnoses were reproducible in all 5 detrusors with multiple site biopsies. Detailed protocols for electron microscopic study and diagnosis of dysfunctional detrusor biopsies were generated.
Conclusions: The protocols eliminate problems that may be encountered in ultrastructural evaluation of biopsies from dysfunctional detrusors, and have been applied readily and successfully in our subsequent studies. Uniformity of structural organization of detrusor allows valid application of the protocols and study criteria to small biopsies obtained from different sites in the bladder wall.