Stenting the Urinary System

Cover......Page 1
STENTING THE URINARY SYSTEM......Page 4
Contents......Page 6
List of contributors......Page 11
Preface to the first edition......Page 19
Preface to the second edition......Page 21
Acknowledgements......Page 23
Dedication......Page 24
Stent geometry......Page 26
Implant duration......Page 27
Anatomical site of implantation......Page 28
Clinical indications......Page 29
Stents currently used in urology......Page 30
Stent design and performance......Page 34
Evaluation of stent design and function......Page 35
Factor: (a) technology influencing (drug, chemical; device, physical); (b) mechanism of action (drug, biological; device, materials)......Page 37
References......Page 38
II History of stents......Page 40
History of ureteral stenting......Page 42
Temporary urethral stents......Page 46
Permanently implanted urethral stents......Page 48
References......Page 49
Stent design evolution......Page 50
Double-J design......Page 51
Placement and removal techniques......Page 52
Evaluation and results......Page 53
State of the art......Page 54
References......Page 55
The original concept......Page 56
Early clinical studies......Page 59
Development of a new (current) delivery system......Page 60
Other clinical applications......Page 61
References......Page 62
Design and development of Memokath®......Page 64
References......Page 65
History......Page 68
References......Page 72
Bioabsorbable materials in urology......Page 74
Anterior urethra......Page 75
Posterior urethra......Page 76
References......Page 77
Introduction......Page 78
Female personnel......Page 79
Female patients......Page 80
Conclusions: practical recommendations15−18......Page 81
References......Page 82
III Stent materials......Page 84
Introduction......Page 86
Cobalt-chromium-based alloys......Page 87
Fundamentals of implant metal corrosion......Page 88
Corrosion in clinical practice......Page 92
Metal alloys as stenting materials......Page 93
Shape memory alloy: Nitinol......Page 94
References......Page 96
Further reading......Page 97
Polytetrafluoroethylene (PTFE)......Page 98
Silicone......Page 100
Polyethylene (PE)......Page 101
Styrenic thermoplastic elastomer......Page 102
How might these polymers be improved for endourological application?......Page 103
References......Page 104
Introduction......Page 106
Implantation site......Page 107
Polyglycolide......Page 108
Degradation of SR-PLA 96 and SR-PGA......Page 109
Expansion properties......Page 111
Structure-property relationships of spiral stents......Page 112
References......Page 113
IV Evaluation of stents......Page 116
Biological evaluation of medical devices......Page 118
Test methods and selection of evaluation tests......Page 119
Reference......Page 121
Results......Page 122
References......Page 124
V Infections and encrustations on stents......Page 126
Encrustation......Page 128
Surface treatment with antimicrobial properties......Page 129
Surface treatment with antimitotic compounds......Page 131
References......Page 132
Biofilm and device-related infection/encrustation......Page 134
Techniques of analysis......Page 135
Coatings......Page 137
Bladder irrigation......Page 138
References......Page 139
Basic considerations......Page 142
Hydrophilic surfaces......Page 145
Bacterial adherence to hydrophilic polymer stents......Page 146
Conclusions......Page 147
References......Page 148
Bacterial factors......Page 150
Studies on bacterial adherence......Page 151
Discussion......Page 152
References......Page 153
Statistical analysis......Page 154
Current urinary tract infection......Page 155
Discussion......Page 156
Conclusions......Page 157
References......Page 158
Complications, including encrustation, and their prevention......Page 160
References......Page 161
VI Ureteral stents: urological disease......Page 162
Physiologic consequences of stent placement......Page 164
Complications......Page 165
Patient tolerance......Page 166
Obstruction associated with infection......Page 167
Extrinsic obstruction......Page 169
Conclusions......Page 170
References......Page 171
Problems associated with stent placement......Page 174
The stent may not disobstruct the system as certainly as would a nephrostomy......Page 175
The stent causes pathological changes to the ureter......Page 176
JJ stent design......Page 177
Clinical experience......Page 179
Obstructing ureteric calculus......Page 180
Obstructed kidney in pregnancy......Page 181
Case history......Page 182
References......Page 184
Procedures......Page 186
Routine stent passage......Page 187
Peel-away sheaths......Page 188
Stone displacement......Page 189
Definitive relief of obstruction......Page 190
Bypassing the obstructed ureter......Page 191
The iliac bifurcation......Page 192
Malignant strictures......Page 193
Conclusions......Page 194
References......Page 195
Basic clinical investigation......Page 196
Materials and methods......Page 197
Stent type 3......Page 198
Results with experimental stents......Page 199
Encrustation......Page 201
New type of reflux-preventing (valve) stent......Page 202
References......Page 204
Introduction......Page 206
Experimental model and results......Page 207
Clinical experience......Page 209
References......Page 213
Introduction......Page 216
Stent hardness......Page 217
Bacterial infection and biofilm formation......Page 218
Stent design......Page 220
Fracture......Page 221
Encrustation and biofilm......Page 222
References......Page 223
Retrieval methods......Page 226
Magnetic stent retrieval revisited......Page 228
References......Page 229
Recommended length of indwelling time......Page 232
Best approach for removing complicated stents......Page 233
Surgical technique......Page 236
Conclusions......Page 237
References......Page 238
Anatomical considerations......Page 240
Retrograde endopyelotomy......Page 241
Results......Page 242
Discussion......Page 244
References......Page 245
Patient selection......Page 248
Technique......Page 249
Results......Page 251
Retrograde techniques......Page 252
Stenting after endopyelotomy......Page 253
Stent design......Page 255
Stent composition......Page 256
Stent size......Page 257
Duration of stenting......Page 258
References......Page 259
Ideal ureteral stent for endopyelotomy......Page 262
Internal or external stent?......Page 263
Stent after endopyelotomy in children......Page 264
References......Page 265
Rationale and indications for stent placement......Page 266
Results of ureteral stenting with ESWL......Page 267
Discussion......Page 268
References......Page 270
Procedure......Page 272
Clinical experience......Page 275
References......Page 276
History of metallic ureteric stents......Page 278
Memokath stent design......Page 279
Memokath removal technique......Page 280
Discussion......Page 281
References......Page 283
Materials and methods......Page 284
Results......Page 285
References......Page 289
Introduction......Page 290
Mechanical ablation of proliferated tissues......Page 292
Recanalization by haemolysis (necrosis) of proliferated tissue......Page 293
Recanalization by retrogradely placed double-J catheter......Page 294
References......Page 295
Indwelling ureteric stents: a source of problems......Page 296
Ureteric Stent Symptoms Questionnaire (USSQ): a valid approach for the assessment of the impact of stents......Page 297
References......Page 298
APPENDIX 1 URETERIC......Page 299
Phase I: assessment of quality of current information and patient expectations......Page 310
Results and discussion......Page 311
References......Page 313
Your urologist is planning to use such a stent for you.......Page 314
Your urologist will explain the specific details applicable to you.......Page 315
What are the effects of obstruction?......Page 316
How is a stent removed?......Page 317
• Urinary symptoms......Page 318
Let us look at this in relation to various daily activities:......Page 319
When should I call for help?......Page 320
VII Ureteral stents: non-urological diseases......Page 322
Incidence and causes of upper urinary tract dilatation and hydronephrosis during pregnancy......Page 324
Diagnosis of upper urinary tract dilatation during pregnancy......Page 325
Interventional therapy for symptomatic upper urinary tract dilatation during pregnancy......Page 326
Clinical experience with pregnant women with symptomatic dilatation of the upper urinary tract......Page 327
Symptoms after stenting......Page 329
Stent versus nephrostomy......Page 330
References......Page 331
Introduction......Page 334
Stent placement at the time of surgery......Page 337
Crush injury......Page 338
Ureteral fistulae......Page 339
Ureteral strictures......Page 340
Radiation injury of the ureter......Page 341
Malignant ureteral obstruction......Page 342
Conclusions......Page 345
References......Page 346
Urological procedures......Page 348
Treatment......Page 349
Ureteral dilatation......Page 350
Conclusions......Page 351
References......Page 352
Materials and methods......Page 354
Summary and discussion......Page 356
References......Page 357
Description and characteristics of the stent......Page 358
Patients......Page 359
Technique......Page 360
Results......Page 361
Discussion......Page 362
References......Page 365
Clinical considerations......Page 366
Materials and methods......Page 367
Results and complications......Page 372
Discussion......Page 373
References......Page 378
VIII Prostatic stents in begin prostatic hyperplasia......Page 380
Introduction......Page 382
Prostate stents......Page 383
Patient selection......Page 384
Stent insertion......Page 385
Radiology......Page 386
Ashford series21......Page 387
Complications (Table 44.5)......Page 390
Discussion......Page 391
References......Page 393
Patients......Page 394
Monitoring......Page 395
Results......Page 396
Discussion......Page 397
References......Page 398
Alternatives......Page 400
Use of the Memokath......Page 401
Conclusions......Page 402
References......Page 403
Introduction......Page 404
Indications for ProstaCoil insertion......Page 405
Insertion technique......Page 406
Removal of the stent......Page 408
Clinical experience and results......Page 409
References......Page 411
History of the Urolume stent......Page 412
References......Page 414
Patients and methods......Page 416
Results......Page 417
Discussion......Page 418
References......Page 419
Three-dimensional imaging of the prostatic urethra......Page 420
References......Page 422
Insertion......Page 424
Results......Page 425
Memotherm™......Page 426
Titanium stent (Titan)......Page 427
References......Page 428
The Barnes stent......Page 430
Results......Page 431
Conclusions......Page 432
References......Page 433
Criteria for a successful stent......Page 434
The Spanner™ device description......Page 435
Selecting the correct stent length: the Surveyor™......Page 436
Insertion and removal procedure......Page 437
Clinical evaluation of the Spanner™......Page 438
Results......Page 439
From BPH to LUTS......Page 440
TUMT, TUNA, ILC, WIT: minimally invasive therapies (MIT) for LUTS......Page 441
References......Page 442
Introduction......Page 444
Results......Page 445
Discussion......Page 446
References......Page 447
Materials and methods......Page 450
SR-PGA spiral stent: randomized study......Page 451
SR-PLA 96 spiral stent......Page 454
Discussion......Page 455
References......Page 456
IX Prostatic stents in prostate cancer......Page 458
Use of intraprostatic stents......Page 460
Conclusions......Page 461
References......Page 462
Stent system......Page 464
Results......Page 465
Discussion......Page 466
References......Page 468
Materials and methods......Page 470
Results......Page 471
Discussion......Page 472
References......Page 473
X Stents in uretheral strictures......Page 476
Configuration......Page 478
Urethrography......Page 479
Dilatation, calibration and endoscopic urethrotomy......Page 480
Graft repair......Page 481
References......Page 482
Wound healing and stent use......Page 484
Urinary diversion systems......Page 485
Indwelling bladder catheters......Page 486
MAGPI, Arap and urethral advancement repairs......Page 487
Complications from urethral drainage catheters......Page 488
References......Page 489
Introduction......Page 490
Why do most urethral strictures recur?......Page 491
Role of stents in urethral strictures......Page 492
Insertion technique......Page 493
Clinical experience and results......Page 497
References......Page 499
Urolume stent......Page 500
Technique......Page 501
Results......Page 502
Discussion......Page 504
References......Page 505
Classic treatment......Page 506
Indications and contraindications......Page 507
Technique......Page 508
Results......Page 510
Adverse events......Page 512
References......Page 514
Clinical experience and results......Page 516
Discussion......Page 517
References......Page 518
Urethral stenting......Page 520
References......Page 523
XI Stents in detrusor-sphincter dyssynergia......Page 526
Removal technique......Page 528
Probable explanations for stent failure......Page 529
References......Page 530
Patient demographics......Page 532
Epithelialization and hyperplasia......Page 533
Complications seen during the trial......Page 534
Need for a longer stent for the sphincter......Page 535
Infertility concerns......Page 536
Discussion......Page 537
References......Page 538
XII Vascular stents......Page 540
Our experience......Page 542
Discussion......Page 545
References......Page 546
Introduction......Page 548
Think of the future......Page 550
Acute PTA-induced rupture......Page 551
Soft post-PTA recoiling stenosis......Page 553
Restenosis......Page 555
Periprocedural management......Page 557
References......Page 558
Conventional management......Page 560
Minimally invasive approach......Page 561
Diagnosis......Page 562
Stent insertion......Page 563
Discussion......Page 565
References......Page 566
XIII The future......Page 568
Introduction......Page 570
Stent insertion (Figs. 71.1 and 71.2)......Page 571
Patients and results......Page 572
References......Page 573
Incomplete expansion......Page 574
Progressive recoil and mechanical collapse (stent crush)......Page 575
Stent discomfort......Page 576
Generic functional role and advantages of paving......Page 577
Solid paving......Page 578
Gel paving......Page 580
Liquid paving......Page 581
Solid paving: prostatic urethra......Page 582
Solid paving: ureter......Page 583
Gel paving as a stand-alone endo-urological method......Page 584
Paving provides superior endoluminal support via conformal moulding and intimate wall apposition, ensuring complete tract expansion......Page 585
Paving as a stand-alone system provides a biodegradable implant with limited potential for surface biofouling, encrustation and infection......Page 586
Paving effectively provides sustained local drug delivery......Page 587
References......Page 588
Permanent stents......Page 590
Temporary stents......Page 591
Stent-shortening at deployment/accurate positioning......Page 592
Incontinence......Page 593
Lumen vs urine flow......Page 594
The new stent design......Page 595
Shape and conformability......Page 596
Sphincter conforming for incontinence prevention......Page 597
Tissue proliferation......Page 598
Shape-regaining ability......Page 599
References......Page 600
Index......Page 602