Bedside Method to Check the Adequacy of Kidney Biopsy Sample with a Smartphone Camera and Macro Lenses: A Prospective Cohort Study

Abstract

Background: The utilization of smartphone-assisted evaluation is emerging in the field of histopathology. This technique improves the adequacy of samples at the bedside, avoids procedure-related complications, reduces unnecessary repeat biopsies, and saves the cost of the procedure. This study aims to compare the number of glomeruli in a renal biopsy specimen obtained by an ultrasound-guided percutaneous needle biopsy, counted at the bedside using a smartphone fitted with a 16-megapixel macro lens (Bedside method) with that observed under a light microscope after the processing of the biopsy specimen (LM method).

Materials and methods: In this prospective cohort study, 24 consecutive adult patients (48 kidney biopsy samples) who underwent kidney biopsies were enrolled. All specimens were extracted by an ultrasound-guided percutaneous renal biopsy from the lower pole of the left kidney. Patients' demographics and clinical data were prospectively collected. The number of glomeruli in all the biopsy specimens was counted using a smartphone fitted with a 16-megapixel macro lens at the bedside (Bedside method) and subsequently under a light microscope by a pathologist after processing the biopsy specimen (LM method). Seven or more glomeruli in the specimen were considered adequate in our study.

Results: The mean age of patients at biopsy was 46.9 ± 16 years with slightly male predominance (54.2%). A total of 47 specimens were obtained from 24 patients. Of the 24 patients, 22 had native kidney biopsy and 2 had renal allograft biopsy. The average number of cores obtained per patient was 1.96. The length of core specimens ranged from 1.5 to 2 cm. A good agreement was found between bedside adequacy and slide adequacy, κ =0.684, P = 0.000. The positive agreement rate and negative agreement rate were 91.4% and 23.1%, respectively.

Conclusion: In the modern era of technology, the smartphone is a good tool to evaluate the adequacy of biopsy specimens at the bedside.

Keywords: Adequacy; biopsies; immunofluorescence; kidney; light microscopy; smartphone.

Figure 1:

Cortical tissue with glomeruli appears as reddish, circular structures.

Figure 2:

Predominant medullar tissue-lacking typical glomerular dotted appearance.