A feedthrough assembly (92, 130, 160, 180, 210) for a medical device (4A, 4B), the feedthrough assembly comprising: a ferrule (104, 132, 182, 212) configured for attachment to the medical device, the ferrule defining: an outer end surface (108, 140, 190, 220) and an inner end surface (110, 142, 192, 222); an aperture (106A-106G, 134, 184A, 184B, 214A, 214B) extending through the ferrule from the outer end surface to the inner end surface, the aperture comprising: a first portion (112, 144, 194A, 194B) extending from the outer end surface to a point (116, 148) at least halfway from the outer end surface to the inner end surface, the first portion having a first diameter (D 1); and a second portion (114, 146, 196A, 196B) extending from the inner end surface toward the point at least halfway from the outer end surface to the inner end surface, the second portion having a second diameter (D 2) that is less than the first diameter, wherein the aperture defines a longitudinal axis (102, 138) extending through the aperture from the outer end surface to the inner end surface; and a ledge (118, 122A, 122B, 136, 198A, 198B) between the first portion of the aperture and the second portion of the aperture, the ledge extending radially inward toward the longitudinal axis; a conductive pin (98A, 98B, 152, 164, 202A, 202B, 228A, 228B) within the aperture; an insulating member (150, 162, 200A, 200B, 224A, 224B) within the aperture and surrounding at least a portion of the conductive pin, wherein the insulating member is configured to electrically insulate the conductive pin from the ferrule, and wherein the ledge and a surface (168, 206A, 206B) of the insulating member adjacent the ledge define a space (169, 207A, 207B) therebetween; and an adhesive coated onto the surface of the insulating member (150, 162, 200A, 200B, 224A, 224B) adjacent the ledge (118, 122A, 122B, 136, 198A, 198B) such that the adhesive fills at least a portion of the space. a ferrule (104, 132, 182, 212) configured for attachment to the medical device, the ferrule defining: an outer end surface (108, 140, 190, 220) and an inner end surface (110, 142, 192, 222); an aperture (106A-106G, 134, 184A, 184B, 214A, 214B) extending through the ferrule from the outer end surface to the inner end surface, the aperture comprising: a first portion (112, 144, 194A, 194B) extending from the outer end surface to a point (116, 148) at least halfway from the outer end surface to the inner end surface, the first portion having a first diameter (D 1); and a second portion (114, 146, 196A, 196B) extending from the inner end surface toward the point at least halfway from the outer end surface to the inner end surface, the second portion having a second diameter (D 2) that is less than the first diameter, wherein the aperture defines a longitudinal axis (102, 138) extending through the aperture from the outer end surface to the inner end surface; and a ledge (118, 122A, 122B, 136, 198A, 198B) between the first portion of the aperture and the second portion of the aperture, the ledge extending radially inward toward the longitudinal axis; an outer end surface (108, 140, 190, 220) and an inner end surface (110, 142, 192, 222); an aperture (106A-106G, 134, 184A, 184B, 214A, 214B) extending through the ferrule from the outer end surface to the inner end surface, the aperture comprising: a first portion (112, 144, 194A, 194B) extending from the outer end surface to a point (116, 148) at least halfway from the outer end surface to the inner end surface, the first portion having a first diameter (D 1); and a second portion (114, 146, 196A, 196B) extending from the inner end surface toward the point at least halfway from the outer end surface to the inner end surface, the second portion having a second diameter (D 2) that is less than the first diameter, wherein the aperture defines a longitudinal axis (102, 138) extending through the aperture from the outer end surface to the inner end surface; and a first portion (112, 144, 194A, 194B) extending from the outer end surface to a point (116, 148) at least halfway from the outer end surface to the inner end surface, the first portion having a first diameter (D 1); and a second portion (114, 146, 196A, 196B) extending from the inner end surface toward the point at least halfway from the outer end surface to the inner end surface, the second portion having a second diameter (D 2) that is less than the first diameter, wherein the aperture defines a longitudinal axis (102, 138) extending through the aperture from the outer end surface to the inner end surface; and a ledge (118, 122A, 122B, 136, 198A, 198B) between the first portion of the aperture and the second portion of the aperture, the ledge extending radially inward toward the longitudinal axis; a conductive pin (98A, 98B, 152, 164, 202A, 202B, 228A, 228B) within the aperture; an insulating member (150, 162, 200A, 200B, 224A, 224B) within the aperture and surrounding at least a portion of the conductive pin, wherein the insulating member is configured to electrically insulate the conductive pin from the ferrule, and wherein the ledge and a surface (168, 206A, 206B) of the insulating member adjacent the ledge define a space (169, 207A, 207B) therebetween; and an adhesive coated onto the surface of the insulating member (150, 162, 200A, 200B, 224A, 224B) adjacent the ledge (118, 122A, 122B, 136, 198A, 198B) such that the adhesive fills at least a portion of the space.