Hsiao et al developed 2 nomograms for evaluating successful reversal of a vasectomy using microsurgery. One nomogram is preoperative and one is postoperative. The authors are from Weill Cornell Medical College, Memorial Sloan-Kettering Cancer Center and the Cleveland Clinic.
Patient selection: male undergoing microsurgical reversal of a vasectomy
Parameters:
(1) age in years, from 25 to 70 years of age
(2) duration of obstruction in years, from 0 to 30
(3) history of previous vasectomy reversal
(4) presence of sperm granuloma
(5) average testis volume in mL from 8.5 to 30 (or greater)
(6) type of reversal procedure performed
|
Parameter
|
Finding
|
Points
|
|
history of previous vasectomy reversal
|
no
|
21
|
|
|
yes
|
0
|
|
sperm granulomas
|
absent
|
0
|
|
|
present
|
10.6
|
|
type of reversal
|
bilateral vasoepididymostomy
|
0
|
|
|
unilateral vasovasostomy and unilateral vasoepididymostomy
|
48
|
|
|
bilateral vasovasostomy
|
78.5
|
points for age =
= (0.03122 * ((years)^2)) - (4.229 * (years)) + 144.4
points for duration of obstruction =
= 82.14 - (2.796 * (years))
points for average testis volume from 8.5 to 22 mL =
= (-0.09178 * ((volume)^2)) + (10.41 * (volume)) - 82.78
points for average testis volume from 22 to 30 mL =
= (-0.9240 * ((volume)^2)) + (40.15 * (volume)) - 335.1
total score =
= SUM(points for all 6 parameters)
Interpretation:
• minimum score: 0
• maximum score: 353
• The higher the score the greater the likelihood of patency.
|
Score
|
Percent with Patency
|
|
0 to 183
|
(0.000639 * ((points)^2)) + (0.1526 * (points)) + 11.05
|
|
183 to 371
|
(-0.000535 * ((points)^2)) + (0.4815 * (points)) - 9.242
|
