1457Vol. 11 | No. 02 | March- April 2014 |U R O LO G Y J O U R N A L Comparison of Different Autogenous Graft Materials for Reconstruction of Large Seg- ment Vas Deferens Defect: Experimental Study in Rat Serdar Nasir,1 Sedat Soyupek,2 Selman Altuntas,3 Ersoy Konas,1 Emir Charles Roach,1 Alper Özorak,2 Sema Bircan4 Correspondence Author: Serdar Nasir, MD Ahmet Rasim Sokak 31/11 Cankaya, Ankara, Turkey. Tel: +90 312 305 1762 Fax: +90 312 309 0445 E-mail: snasir@hacettepe.edu. tr;snasir72@gmail.com Received November 2012 Accepted June 2013 1 Department of Plastic and Re- constructive Surgery, Hacettepe University, School of Medicine, Ankara, Turkey. 2 Department of Urology, Süley- man Demirel University, School of Medicine, Isparta, Turkey. 3 Department of Plastic and Reconstructive Surgery, Süley- man Demirel University, School of Medicine, Isparta, Turkey. 4 Department of Pathology, Süleyman Demirel University, School of Medicine, Isparta, Turkey. Purpose:‎Vasectomy‎is‎one‎of‎the‎most‎common‎urological‎operations‎performed,‎and‎pro- vides‎permanent‎contraception.‎Many‎vasectomized‎men‎ultimately‎seek‎vasectomy‎reversal‎ because‎of‎unforeseen‎changes‎in‎lifestyle.‎Vasovasostomy‎has‎varying‎rates‎of‎success.‎In‎ this‎study,‎we‎utilize‎vas‎deferens‎(VD),‎artery,‎and‎vein‎grafts‎to‎reconstruct‎30%‎and‎50%‎ defects‎of‎the‎total‎vas‎deferens‎length. Materials and Methods:‎Forty‎two‎male‎Wistar‎rats‎were‎divided‎into‎three‎groups‎as‎VD‎ graft,‎carotid‎artery‎and‎external‎jugular‎vein‎transplantations.‎Each‎group‎was‎equally‎divided‎ into‎2‎different‎subgroups‎according‎to‎the‎length‎of‎transplant‎material‎as‎1.0‎cm‎(n‎=‎7)‎and‎ 1.5‎cm‎(n‎=‎7).‎To‎evaluate‎whether‎these‎materials‎may‎be‎used‎for‎long‎segment‎vas‎deferens‎ reconstruction,‎the‎patency‎rate,‎partial‎or‎total‎graft‎occlusion,‎and‎histologic‎examination‎of‎ all‎specimens‎were‎examined.‎ Results:‎No‎patency‎was‎found‎in‎any‎of‎the‎grafts‎and‎many‎of‎them‎suffered‎destructive‎ changes‎in‎anatomic‎structure.‎Sperm‎granulomas‎were‎determined‎around‎the‎testicular‎side‎ anastomosis‎due‎to‎accumulated‎semen‎fluid‎which‎was‎in‎our‎belief,‎a‎result‎of‎aperistaltic‎ zone‎caused‎by‎the‎grafts Conclusion:‎‎When‎the‎poor‎results‎obtained‎in‎our‎study‎are‎put‎into‎perspective,‎vasoe- pididymostomy‎is‎the‎only‎treatment‎method‎to‎date‎for‎reconstruction‎of‎large‎segment‎vas‎ deferens‎defects.‎ Keywords:‎vas‎deferens;‎vasovasostomy;‎rats;‎vasectomy;‎transplantation;‎graft‎survival;‎ animals.‎ SEXUAL DYSFUNCTION AND INFERTILITY 1458 | Sexual Dysfunction And Infertility INTRODUCTION The‎safest‎and‎most‎cost-effective‎treatment‎option‎for‎the‎reversal‎of‎the‎vasectomies‎remains‎micro-surgical reconstruction, which also allows natural conception.(1)‎The‎success‎rate‎of‎this‎procedure‎depends‎ on‎a‎myriad‎of‎factors,‎including‎the‎performing‎surgeon’s‎ skill,‎presence‎of‎antisperm‎antibodies,‎high‎intravasal‎and‎ epididymal‎pressure‎that‎develops‎after‎vasectomy,‎and‎the‎ obstruction‎interval‎between‎the‎vasectomy‎and‎reversal. (2,3)‎Technical‎failure‎of‎human‎vas‎deferens‎(VD)‎recon- struction‎mainly‎occurs‎several‎weeks‎to‎months‎after‎sur- gery,‎usually‎as‎a‎result‎of‎stricture‎of‎the‎anastomosis.‎The‎ narrowing‎and‎obliteration‎of‎the‎lumen‎takes‎place‎due‎to‎ granuloma‎formation‎at‎the‎site‎of‎anastomosis,‎and‎traction‎ on‎or‎devascularization‎of‎the‎VD‎wall,‎which‎eventually‎ leads‎to‎sperm‎leakage‎after‎the‎reversal.‎Prosthetic‎stents‎ have‎been‎used‎to‎simplify‎the‎procedure‎and‎prevent‎this‎ sperm‎leakage.‎Autodilating‎stents‎have‎been‎put‎forth‎as‎a‎ possible‎solution‎for‎preventing‎the‎secondary‎stricture‎of‎ the‎anastomosis.‎Also,‎by‎preventing‎sperm‎extravasation,‎ there‎ is‎ less‎ perivasal‎ inflammation,‎ reducing‎ secondary‎ stricture‎at‎the‎site‎of‎the‎anastomosis.(4,5) Wald‎and‎colleagues‎evaluated‎a‎biodegradable‎graft‎for‎re- construction‎of‎rat‎vasa‎deferentia‎with‎long‎obstructed‎or‎ missing‎ segments‎ with‎ or‎ without‎ some‎ medical‎ therapy.‎ They‎ found‎ that‎ potential‎ role‎ for‎ biodegradable‎ grafts‎ in‎ the‎reconstruction‎of‎VD‎with‎long‎obstructed‎segments.(4,6)‎ Rothman‎and‎colleagues(7)‎carried‎out‎a‎randomized‎clinical‎ trial‎comparing‎the‎usual‎2-layer‎microsurgical‎vasectomy‎re- versal‎against‎a‎procedure‎using‎the‎new‎stent.‎As‎interesting‎ result,‎they‎found‎that‎the‎microscopic‎vasovasostomy‎(VV)‎ results‎in‎greater‎pregnancy‎rates‎than‎VV‎using‎the‎absorb- able‎stent.‎They‎did‎not‎recommend‎absorbable‎stent‎due‎to‎ poor‎measured‎patency‎ratio‎and‎sperm‎motility(8) were pre- ferred‎for‎reconstruction‎of‎vasectomy.(7) On‎the‎other‎hand,‎large‎sections‎of‎the‎VD‎may‎be‎affected‎ after‎some‎surgical‎operations‎such‎as‎hernia‎repair,‎hydro- celectomy,‎or‎complications‎of‎vasectomy.‎In‎the‎majority‎of‎ such‎cases,‎the‎length‎of‎vas‎defects‎renders‎direct‎vasovaso‎ anastomosis‎either‎impossible‎or‎too‎risky,‎due‎to‎increased‎ tension‎in‎the‎anastomosis‎area.‎To‎overcome‎this‎obstacle,‎ extra‎ anatomical‎ (sub-‎ and‎ suprapubic)‎ vas‎ rerouting‎ was‎ performed‎to‎allow‎shortening‎of‎the‎necessary‎vas‎length‎ for‎anastomosing.‎This‎technique‎has‎been‎established‎to‎be‎ one‎of‎the‎most‎technically‎challenging‎type‎of‎surgery‎of‎the‎ male‎reproductive‎system.‎Another‎interesting‎possibility‎for‎ resolution‎of‎a‎vas‎defect‎might‎be‎the‎use‎of‎a‎vascular‎trans- plant. The‎aim‎of‎this‎study‎presented‎was‎to‎determine‎experimen- tally‎if‎a‎vas‎defect‎could‎be‎repaired‎either‎by‎vas‎transplan- tation‎or‎by‎transplantation‎of‎an‎artery‎and‎vein‎graft.‎Anoth- er‎objective‎was‎to‎determine‎critical‎maximum‎length‎that‎ can‎be‎transplanted‎while‎still‎achieving‎acceptable‎patency‎ for‎sperm‎transport. MATERIAL AND METHODS In‎our‎experimental‎setting,‎we‎used‎male‎adult‎inbred‎Wistar‎ rats,‎weighing‎250-300‎g,‎mean‎270‎g.‎Females‎of‎the‎same‎ Figure 1. View of scrotal contents of rat. Keys: T, testis; E, epididymis; VD, vas deferens. Figure 2. Completed anastomosis of vas deferens autograft. Keys: TS, testicular side anastomosis; AS, abdominal side anas- tomosis. 1459Vol. 11 | No. 02 | March- April 2014 |U R O LO G Y J O U R N A L Vas Deferens Reconstruction | Nasir et al race‎and‎standards‎were‎used‎as‎vascular‎donors‎in‎the‎ex- periment.‎The‎study‎was‎conducted‎in‎accordance‎with‎the‎ Guidelines‎for‎Animal‎Care‎and‎Research‎of‎the‎university.‎ The‎animals‎were‎kept‎in‎a‎room‎with‎standard‎environmen- tal‎conditions‎and‎fed‎ad‎libidum.‎The‎male‎rats‎(n‎=‎42)‎were‎ divided‎into‎three‎groups‎as‎VD‎graft,‎carotid‎artery‎and‎ex- ternal‎jugular‎vein‎transplantations.‎Each‎group‎was‎equally‎ divided‎into‎2‎different‎subgroups‎according‎to‎the‎length‎of‎ transplant‎material‎as‎1.0‎cm‎(n‎=‎7)‎and‎1.5‎cm‎(n‎=‎7).‎ Operative Technique Operations‎took‎place‎under‎ketamine‎(90‎mg/kg)‎and‎xyla- zine‎(10‎mg/kg)‎anesthesia.‎Supplementary‎doses‎were‎given‎ as‎necessary.‎A‎surgical‎operation‎microscope‎(M‎651‎Surgi- cal‎Microscope;‎Leica,‎Sweden),‎standard‎microvascular‎in- struments,‎and‎8-0‎nylon‎suture‎with‎75‎µm‎needle‎were‎used.‎ The‎surgical‎procedure‎and‎postoperative‎observations‎were‎ performed‎by‎the‎leading‎author.‎ The‎left‎side‎was‎preferred‎for‎the‎experimental‎groups.‎An‎ abdominal‎midline‎incision‎was‎used‎to‎explore‎the‎VD‎fol- lowed‎by‎the‎opening‎of‎the‎internal‎spermatic‎fascia‎and‎the‎ VD,‎which‎was‎lying‎loose‎next‎to‎the‎funiculus,‎which‎was‎ easily‎exposed‎leaving‎the‎scrotal‎contents‎in‎situ.‎Two‎differ- ent‎lengths‎of‎VD‎segment‎(1.0‎cm‎and‎1.5‎cm)‎were‎resected‎ to‎create‎defects‎in‎VD‎and‎these‎segments‎represented‎30%‎ and‎50%‎of‎the‎total‎VD‎length‎respectively.‎These‎defects‎ were‎ reconstructed‎ using‎ VD,‎ carotid‎ artery‎ and‎ external‎ Figure 3. (A) View of resected vas deferens segment (1.5 cm) with similar length of the arterial graft (1.5 cm). Arterial graft is seen shortly compared to vas deferens defect due to elastic shrinkage of vessel wall. (B) Completed vas deferens- arterial graft anastomoses. Table . Results of anastomosis condition in all groups. Variables Autotransplantation Groups Artery Graft Groups Vein Graft Groups Total Testicular site anastomosis 1 cm 1.5 cm 1 cm 1.5 cm 1 cm 1.5 cm ------ Normal 2/7 1/7 2/7 0/7 0/7 0/7 5/42 Partial stenosis 2/7 3/7 1/7 2/7 1/7 1/7 10/42 Occluded 3/7 3/7 4/7 5/7 6/7 6/7 27/42 Abdominal site anastomosis 1 cm 1.5 cm 1 cm 1.5 cm 1 cm 1.5 cm ------ Normal 1/7 0/7 1/7 1/7 0/7 0/7 3/42 Partial stenosis 2/7 3/7 1/7 4/7 0/7 0/7 10/42 Occluded 4/7 4/7 5/7 2/7 7/7 7/7 29/42 1460 | Sexual Dysfunction And Infertility jugular‎vein‎grafts‎and‎grafts‎used‎for‎reconstruction‎were‎the‎ same‎length‎as‎the‎resected‎vas‎segment.‎ Autotransplantation Group (n =‎14) In‎this‎group,‎resected‎segment‎of‎VD‎were‎anastomosed‎in‎ the‎same‎place.‎Anastomoses‎were‎performed‎by‎applying‎4‎ stitches‎and‎only‎seromuscular‎suture‎was‎placed‎using‎8-0‎ non-absorbable‎nylon.‎The‎first‎two‎sutures‎were‎placed‎at‎ opposite‎ends‎180‎degrees‎apart‎precisely‎aligning‎mucosa‎of‎ two‎ends‎of‎VD.‎One‎suture‎was‎placed‎between‎these‎stitch- es‎on‎each‎of‎the‎front‎and‎back‎wall. Artery and Vein Groups Carotid‎artery‎and‎external‎jugular‎vein‎grafts‎were‎harvested‎ the‎same‎length‎(1.0‎cm‎and‎1.5‎cm)‎as‎the‎vas‎defect‎from‎ the‎female‎Wistar‎rats.‎For‎the‎anastomosis‎of‎VD‎with‎artery‎ and‎vein‎grafts,‎the‎same‎operative‎technique‎described‎as‎above‎ was‎used‎with‎exception‎that‎only‎full-thickness‎sutures‎were‎ applied‎through‎the‎vascular‎wall.‎The‎skin‎was‎closed‎with‎4-0‎ silk‎sutures‎in‎every‎rat‎after‎the‎application‎pf‎the‎procedure.‎ Final Examination Four‎weeks‎postoperatively‎the‎rats‎were‎euthanized.‎Occur- rence‎of‎sperm‎granulomas(9)‎was‎recorded.‎The‎abdominal‎ end‎of‎ the‎VD‎after‎both‎anastomosis‎zones‎ in‎all‎groups‎ were‎transected‎and‎the‎intraluminal‎fluid‎was‎microscopi- cally‎examined‎for‎functional‎patency‎with‎the‎occurrence‎of‎ sperm‎at‎400‎×‎magnification.‎The‎VDs‎were‎transected‎dis- tal‎from‎the‎anastomoses‎and‎functional‎patency‎checked‎by‎ smear‎examination‎to‎see‎the‎presence‎of‎sperm‎at‎the‎distal‎ portion.‎The‎transplanted‎segment‎was‎then‎incised‎longitudi- nally‎in‎order‎to‎explore‎if‎there‎are‎any‎occlusions‎or‎partial‎ stenosis.‎Equal‎segments‎of‎the‎VD,‎artery‎and‎vein‎grafts‎ with‎the‎anastomoses‎included‎were‎excised.‎For‎the‎control‎ specimen,‎ductus‎deferens‎from‎one‎male‎animal,‎carotid‎ar- tery‎and‎external‎jugular‎vein‎from‎one‎female‎animal‎were‎ harvested.‎All‎specimens‎were‎fixed‎in‎neutral‎buffered‎4%‎ formalin‎and‎paraffin‎embedded‎for‎further‎slicing.‎Multiple‎ tissue‎segments‎of‎each‎specimen‎were‎taken‎from‎anasto- mosis‎area‎and‎proximal‎and‎distal‎to‎the‎anastomosis.‎All‎ samples‎were‎cut‎at‎4‎µm‎thickness‎and‎slides‎were‎stained‎ with‎hematoxylin‎and‎eosin.‎All‎the‎samples‎were‎examined‎ by‎the‎same‎pathologist.‎ Figure 4. Sperm granulomas in the vein graft. This collection populated neighbor areas of testicular side anastomosis while abdominal side anastomosis did not occupied this structure. Figure 6. (A) Control artery tissue (hematoxylin and eosin × 40), (B) vascular wall was fragmented in artery graft, and mix inflammatory cells and also suture material (arrow) were seen (hematoxylin and eosin × 200). 1461Vol. 11 | No. 02 | March- April 2014 |U R O LO G Y J O U R N A L RESULTS Autotransplantation Group Anatomical‎ patency‎ was‎ not‎ preserved‎ in‎ any‎ of‎ the‎ seg- ments.‎In‎the‎1‎cm-long‎graft‎group,‎normal,‎partial‎stenosis,‎ and‎occlusion‎were‎observed‎as‎2/7,‎2/7‎and‎3/7‎in‎testicu- lar‎side‎(TS)‎anastomosis,‎and‎1/7,‎2/7‎and‎4/7‎in‎abdominal‎ side‎(AS)‎anastomosis,‎respectively.‎In‎the‎1.5‎cm‎long‎graft‎ group,‎normal,‎partial‎stenosis,‎and‎occlusion‎were‎observed‎ as‎1/7,‎3/7,‎and‎3/7‎in‎TS‎anastomosis,‎and‎0/7,‎3/7,‎and‎4/7‎ in‎AS‎anastomosis‎respectively.‎Sperm‎granulomas‎(SG)‎oc- curred‎in‎all‎14‎segments‎and‎they‎were‎situated‎12/14‎and‎ 2/14‎TS‎and‎AS‎anastomoses,‎respectively.‎ Artery Graft Group Anatomical‎patency‎was‎not‎observed‎in‎any‎of‎the‎segments.‎ In‎the‎1‎cm-‎long‎graft‎group,‎normal,‎partial‎stenosis,‎and‎oc- clusion‎were‎observed‎as‎2/7,‎1/7‎and‎4/7‎in‎TS‎anastomosis,‎ and‎1/7,‎1/7‎and‎5/7‎in‎AS‎anastomosis,‎respectively.‎In‎the‎ 1.5‎cm‎long‎graft‎group,‎normal,‎partial‎stenosis,‎and‎occlu- sion‎0/7,‎2/7,‎and‎5/7‎were‎observed‎as‎in‎TS‎anastomosis,‎ and‎1/7,‎4/7,‎and‎2/7‎in‎AS‎anastomosis,‎respectively.‎SG‎oc- curred‎in‎all‎12‎segments‎and‎they‎were‎situated‎11/12‎and‎ 1/14‎TS‎and‎AS‎anastomoses,‎respectively. Vein Graft Group Anatomical‎patency‎was‎not‎recorded‎in‎any‎of‎the‎segments.‎ In‎the‎1‎cm-‎long‎graft‎group,‎normal,‎partial‎stenosis,‎and‎oc- clusion‎were‎observed‎as‎0/7,‎1/7‎and‎6/7‎in‎TS‎anastomosis,‎ Figure 5. (A) Control vas deferens (hematoxylin and eosin × 40), (B) the lumen was obliterated and the thickness of muscle layer was reduced, and subepithelial area was expanded by fibrous tissue growing and inflammatory cells in the vas deferens graft (hematoxylin and eosin × 100). Figure 7. (A) Control vein tissue (hematoxylin and eosin × 100), (B) necrotic debris and semen material filled the vein lumen and covered the inner surface, and also inflammatory cells were seen in the vascular wall and the lumen of graft (hematoxylin and eosin × 100). Vas Deferens Reconstruction | Nasir et al 1462 | Sexual Dysfunction And Infertility and‎0/7,‎0/7‎and‎7/7‎in‎AS‎anastomosis,‎respectively.‎In‎the‎ 1.5‎cm‎long‎graft‎group,‎normal,‎partial‎stenosis‎and‎occlu- sion‎were‎observed‎as‎0/7,‎1/7,‎and‎6/7‎in‎TS‎anastomosis,‎ and‎0/7,‎0/7,‎and‎7/7‎in‎AS‎anastomosis,‎respectively.‎SG‎oc- curred‎in‎all‎12‎segments‎and‎they‎were‎situated‎12/12‎and‎ 0/12s‎TS‎and‎AS‎anastomoses,‎respectively. Intraluminal Fluid Examination No‎ motile‎ sperm‎ were‎ found‎ in‎ intraluminal‎ fluid‎ micro- scopically.‎Only‎necrotic‎cells‎and‎debris‎were‎observed‎upon‎ smear‎examination. Histological Examination VD Grafts The‎muscle‎layer‎of‎the‎graft‎was‎reduced,‎to‎between‎10‎ and‎35%‎of‎the‎original‎thickness‎in‎most‎of‎the‎cases.‎For‎ some‎cases‎especially‎in‎ the‎longer‎grafts,‎ the‎whole‎wall‎ was‎replaced‎by‎fibrous‎tissue.‎Atrophic‎epithelial‎layer‎was‎ observed‎with‎intact‎epithelium‎in‎short‎grafts‎while‎longer‎ grafts‎had‎only‎remnants‎of‎an‎atrophic‎epithelium.‎ Artery Grafts The‎thickness‎of‎the‎muscular‎layer‎was‎slightly‎or‎moder- ately‎reduced.‎Inflammatory‎changes‎were‎present,‎especially‎ with‎massive‎SG.‎Intimal‎layer‎was‎destroyed‎and‎detached‎ from‎basal‎layer‎and‎protruded‎into‎the‎vascular‎lumen.‎ Vein Grafts The‎whole‎walls‎of‎vein‎grafts‎were‎invaded‎by‎inflamma- tory‎cells.‎The‎lumens‎of‎many‎vein‎grafts‎were‎occluded‎by‎ pannus-like‎tissue,‎which‎is‎granulation‎and‎fibrous‎tissues.‎ Intimal‎layer‎was‎not‎found‎in‎many‎grafts‎and‎it‎was‎de- tached‎from‎basal‎layer‎into‎the‎lumen.‎‎ DISCUSSION There‎are‎a‎lot‎of‎techniques‎described‎for‎the‎reversal‎of‎va- sectomies‎and‎the‎reconstruction‎of‎defects‎in‎the‎vas‎defer- ence‎area.‎It‎was‎reported‎that‎one-layer‎VV‎and‎two-layer‎ VV‎seem‎to‎be‎equal‎with‎regard‎to‎vasal‎patency.(9)‎Further- more‎we‎preferred‎one‎layer‎VV‎as‎our‎microsurgical‎skills‎ with‎our‎clinical‎cases.‎We‎believed‎that‎one‎layer‎approxi- mation‎of‎vasal‎ends‎is‎easier,‎quicker‎and‎safer‎compare‎to‎ two‎layer‎technique. ‎However,‎in‎large‎defects,‎when‎the‎VV‎is‎not‎possible‎due‎to‎ technical‎reasons,‎hollow‎structures‎such‎as‎vessels‎might‎come‎ up‎as‎an‎idea‎for‎grafting.‎However,‎since‎there‎is‎contractility‎ present‎in‎VD,‎especially‎due‎to‎parasympathetic‎stimulation,(8) it‎is‎extremely‎hard‎to‎demonstrate‎that‎contractility‎with‎graft‎ materials.‎In‎human,‎the‎VD‎epididymis‎and‎efferent‎ducts‎has‎ proximodistal‎increase‎in‎the‎muscle‎layer,‎and‎also‎the‎thick- ness‎of‎the‎muscle‎layer‎is‎greater‎than‎any‎structure‎in‎human‎ body,‎compared‎to‎its‎lumen.‎VD‎and‎distal‎epididymis‎propel‎ the‎sperm‎with‎their‎rhythmic‎contractions,‎and‎if‎this‎peristal- sis‎is‎disrupted,‎a‎sperm‎granuloma‎might‎occur. It‎was‎reported‎thirty‎years‎ago‎that‎microsurgical‎VV‎tech- nique‎for‎vasectomy‎reversal‎has‎resulted‎in‎significantly‎im- proved‎outcomes‎compared‎to‎older‎techniques.(10) Patency rates‎ after‎ microsurgical‎VV‎ using‎ non-absorbable‎ sutures‎ have‎reached‎99%.‎The‎semen‎can‎pass‎through‎the‎anasto- mosis‎zone‎as‎well‎as‎an‎aperistaltic‎segment‎in‎anastomosis‎ zone‎shortly‎after‎VV.‎The‎obstructive‎interval‎after‎vasec- tomy‎is‎a‎significant‎determinant‎of‎the‎patency‎and‎preg- nancy‎rates.‎Which‎can‎be‎exemplified‎by‎the‎patency‎and‎ pregnancy‎rates‎decreased‎88%‎and‎53%‎between‎3-8‎years‎ after‎vasectomy.(11)‎Those‎poor‎results‎may‎be‎related‎to‎long‎ segment‎fibrosis‎in‎VD‎following‎a‎long‎term‎interval‎after‎ vasectomy.‎Shandling‎and‎Janik‎found‎that‎simply‎clamping‎ the‎vas‎of‎rats‎could‎produce‎muscle‎disruption‎and‎fibrosis. (12)‎The‎thick‎muscle‎layers‎can‎easily‎get‎damaged‎with‎an‎ insult‎minor‎than‎vasectomy‎which‎triggers‎fibrosis.‎Inflam- mation‎and‎fibrosis‎worsening‎the‎whole‎scenario‎by‎causing‎ more‎extensive‎damage‎with‎vasectomy.(13)‎The‎problem‎as- sociated‎with‎vasectomy‎or‎iatrogenic‎injury‎to‎the‎VD‎in- clude‎a‎long‎obstructive‎interval,‎unpredictable‎length‎of‎oc- clusion,‎injury‎to‎the‎testicular‎blood‎supply‎and‎these‎factors‎ may‎cause‎long‎segment‎injuries‎to‎VD.(14)‎Vasoepididymos- Figure 8. Normal seminiferous tubules were seen at the lower area, but some tubules at the upper side (arrows) were degener- ated and filled with necrotic and cellular debris (hematoxylin and eosin × 100). 1463Vol. 11 | No. 02 | March- April 2014 |U R O LO G Y J O U R N A L tomy‎may‎be‎performed‎to‎resolve‎large‎VD‎defects.(15)‎But‎ advanced‎microsurgical‎techniques‎are‎necessary‎and‎it‎has‎a‎ lower‎pregnancy‎and‎patency‎rate‎compared‎to‎a‎VV.(16)‎Also, prosthetic‎stents‎are‎not‎long‎enough‎to‎use‎for‎microsurgi- cal‎VV‎reconstruction‎of‎VD‎defect.‎Although‎experimental‎ VD‎auto-transplantation‎is‎not‎applicable‎for‎clinical‎opera- tions,‎Carringer‎evaluated‎VD‎and‎vascular‎grafts‎to‎repair‎ large‎VD‎defect‎in‎rats.(17)‎However,‎low‎patency‎rates‎were‎ reported‎for‎these‎grafts‎and‎this‎result‎was‎explained‎with‎ poor‎graft‎viability‎and‎absent‎neural‎innervations.‎Carringer‎ postulated‎ that‎ graft‎ neovascularization‎ occurred‎ from‎ the‎ margins‎of‎the‎transplant‎and‎the‎outcome‎depended‎on‎the‎ “bridging‎phenomenon”.‎This‎phenomenon,‎to‎elaborate,‎is‎ the‎growth‎of‎vessels‎anastomosing‎with‎the‎vessels‎of‎the‎ transplant.(17) The‎total‎length‎of‎rat‎VD‎is‎3-3.5‎cm.‎In‎our‎study,‎we‎aimed‎ to‎create‎VD‎defects‎at‎30%‎and‎50%‎of‎the‎total‎length,‎mak- ing‎1‎and‎1.5‎cm‎segment‎resections‎from‎VD‎respectively.‎ After‎the‎defects‎were‎created,‎we‎examined‎the‎results‎com- paring‎various‎grafts‎which‎had‎different‎muscle‎layer‎thick- nesses.‎We‎found‎no‎patency‎in‎either‎auto-transplantation‎or‎ vascular‎grafts‎groups.‎However,‎rates‎of‎vein‎graft‎occlusion‎ were‎higher‎compared‎to‎its‎artery‎groups.‎We‎hypothesized‎ that‎this‎result‎was‎due‎to‎the‎thick‎wall‎of‎the‎artery‎graft‎ preventing‎lumen‎from‎collapsing,‎thus‎creating‎lower‎graft‎ occlusion, although they still yielded poor total patency out- comes.‎We‎have‎some‎differences‎from‎Carringer’s‎neovas- cularization hypothesis.(17)‎Main‎neovascularization‎mecha- nism‎of‎all‎grafts‎is‎provided‎by‎sprouting‎new‎vessels‎from‎ donor‎site‎or‎formation‎of‎anastomoses‎between‎graft‎and‎ host‎vessels.‎Graft’s‎nutrition‎ is‎dependent‎on‎plasma‎dif- fusion‎until‎new‎vessels‎form.‎It‎is‎known‎that‎thin‎tissues‎ gain‎enough‎neovascularization‎providing‎graft‎nutrition‎in‎a‎ shorter‎time‎than‎thick‎tissues.(18) Although we did not con- duct‎detailed‎examinations‎in‎order‎to‎determine‎the‎differ- ence‎of‎neovascularization‎quality,‎all‎groups‎displayed‎the‎ same‎histological‎views‎of‎new‎vessels‎sprouting‎under‎light‎ microscopic‎study.‎Artery‎and‎vein‎grafts‎which‎have‎thin‎ walls‎may‎cause‎mechanical‎obstruction‎in‎their‎lumen‎as‎a‎ result‎of‎collapse‎and‎kinking.‎Mechanical‎blockage‎invites‎ inflammation‎and‎fibrous‎tissue‎growing‎into‎luminal‎space‎ as‎a‎result,‎permanent‎lumen‎obstruction.‎We‎have‎observed‎ intraluminal‎fibrous‎tissue‎in‎some‎histological‎sections‎dur- ing‎light‎microscopic‎study.‎In‎our‎opinion,‎the‎main‎prob- lem‎of‎lower‎patency‎rates‎were‎related‎to‎long‎VD‎defects‎ which‎create‎aperistaltic‎zones‎during‎semen‎transport.‎Al- though‎there‎is‎no‎evidence‎of‎VD‎contraction‎except‎during‎ the‎ejaculation‎period,‎thick‎muscle‎and‎mucosal‎layer‎of‎VD‎ may‎propel‎semen‎during‎asexual‎period‎as‎well.‎ CONCLUSION We‎concluded‎that‎vein‎and‎VD‎grafts‎are‎not‎useful‎for‎long‎ segment‎defect‎reconstructions‎which‎are‎30-50%‎of‎the‎VD‎ length‎in‎rats.‎We‎think‎that‎any‎material‎used‎for‎large‎VD‎ defect‎reconstruction‎must‎have‎peristaltic‎movement‎in‎or- der‎to‎push‎the‎semen‎forward.‎Furthermore,‎we‎concluded‎ that‎there‎is‎no‎autogenic‎or‎prosthetic‎material‎has‎this‎spe- cial‎function‎to‎perform‎semen‎transportation.‎For‎this‎reason,‎ vasoepididymostomy‎seems‎to‎be‎only‎indisputable‎solution‎ for‎long‎segment‎VD‎reconstruction. CONFLICT OF INTEREST None declared. Vas Deferens Reconstruction | Nasir et al REFERENCES 1. Pavlovich CP, Schlegel PN. Fertility options after vasectomy: a cost-effectiveness analysis. Fertil Steril. 1997;67:133-41. 2. Silber SJ. Microscopic vasectomy reversal. Fertil Steril. 1977;28:1191-202. 3. Belker AM, Thomas AJ Jr, Fuchs EF, Konnak JW, Sharlip ID. Results of 1,469 microsurgical vasectomy reversals by the Vasovasostomy Study Group. J Urol. 1991;145:505-11. 4. Simons CM, De Young BR, Griffith TS, et al. Early microre- canalization of vas deferens following biodegradable graft implantation in bilaterally vasectomized rats. Asian J Androl. 2009;11:373-8. 5. Holoch PA, Mallapragada SK, Ariza CA, Griffith TS, Deyoung BR, Wald M. Micro-recanalization in a biodegradable graft for reconstruction of the vas deferens is enhanced by silde- nafil citrate. Asian J Androl. 2010;12:814-8. 6. Rosevear HM, Krishnamachari Y, Ariza CA, et al. Effect of com- bined locally delivered growth factors and systemic sildena- fil citrate on microrecanalization in biodegradable conduit for vas deferens reconstruction. Urology. 2012;79:967 e1-4. 7. Rothman I, Berger RE, Cummings P, Jessen J, Muller CH, Chapman W. Randomized clinical trial of an absorbable stent for vasectomy reversal. J Urol. 1997;157:1697-700. 8. Elzanaty S, Dohle GR. Vasovasostomy and predictors of vasal patency: a systematic review. Scand J Urol Nephrol. 2012;46:241-6. 1464 | 9. Cipriani R, Contedini F, Santoli M, et al. Abdominal wall transplantation with microsurgical technique. Am J Trans- plant. 2007;7:1304-7. 10. Owen ER. Microsurgical vasovasostomy: a reliable vasec- tomy reversal. J Urol. 2002;167(2 Pt 2):1205. 11. O'Brien BM, MacLeod AM, Hayhurst JW, Morrison WA. Suc- cessful transfer of a large island flap from the groin to the foot by microvascular anastomoses. Plast Reconstr Surg. 1973;52:271-8. 12. Shandling B, Janik JS. The vulnerability of the vas deferens. J Pediatr Surg. 1981;16:461-4. 13. Bowins B. Vasectomy: The Cruelest Cut of All. West Consho- hocken: Infinity Publishing; 2006. 14. Sheynkin YR, Hendin BN, Schlegel PN, Goldstein M. Micro- surgical repair of iatrogenic injury to the vas deferens. J Urol. 1998;159:139-41. 15. Kramer WC, Meacham RB. Vasal reconstruction above the internal inguinal ring: what are the options? J Androl. 2006;27:481-2. 16. Wei FC, Jain V, Celik N, Chen HC, Chuang DC, Lin CH. Have we found an ideal soft-tissue flap? An experience with 672 an- terolateral thigh flaps. Plast Reconstr Surg. 2002;109:2219- 26. 17. Carringer M, Pedersen J, Schnürer LB. Experimental vas replacement by either vas or a vascular graft. Scand J Urol Nephrol. 1995;29:97-102. 18. Kimura N, Satoh K, Hosaka Y. Microdissected thin perforator flaps: 46 cases. Plast Reconstr Surg. 2003;112:1875-85. Sexual Dysfunction And Infertility