PeRSPeCTIVeS. The Shangring device for simplified adult circumcision. Puneet Masson, Philip S. Li, Mark A. Barone and Marc Goldstein

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1 PeRSPeCTIVeS opinion The Shngring device for simplified dult circumcision Puneet Msson, Philip S. Li, Mrk A. Brone nd Mrc Goldstein Astrct Adult mle circumcision reduces HIV trnsmission through vginl intercourse nd is eing promoted in res where HIV is widespred. Conventionl surgicl circumcision involves suturing nd thus requires prctitioners with surgicl skills. It is lso ssocited with complictions, including leeding nd infection, especilly in resource-poor settings. The ShngRing (Wuhu Snnd Medicl Tretment Applince Technology Co. Ltd, Wuhu City, Chin) hs een used to perform thousnds of circumcisions in dult men, principlly in Chin. It consists of two concentric plstic rings tht sndwich the foreskin of the penis, llowing circumcision without stitches or notle leeding. As well s sustntilly reduced opertive times, ShngRing dult mle circumcision is ssocited with low compliction rte, nd the technique cn esily e tught to oth physicin nd nonphysicin personnel. The simple technique nd successful outcomes ssocited with the ShngRing procedure men tht the device could enle stndrdiztion of dult mle circumcision, helping HIV prevention efforts throughout the developing world. Msson, P. et l. Nt. Rev. Urol. dvnce online puliction 12 Octoer 2010; doi: /nrurol Introduction Mle circumcision represents one of the most common surgicl procedures, with prevlence of 70% in the us nd 30% worldwide. 1 3 in the us, the vst mjority of circumcisions re performed on neworn ies; however, dult circumcision is currently on the rise in other popultions, especilly in prts of fric where clinicl trils hve demonstrted tht circumcised men hve reduced risk of cquiring sexully trnsmitted infections, such s those cused y humn ppillomvirus, herpes simplex virus, nd Hiv. 4 6 three rndomized controlled trils in Keny, ugnd, nd south fric hve reported tht dult mle circum cision is ssocited with sustntilly reduced risk of cquiring Hiv infection vi vginl intercourse. 7 9 Consequently, the who, the Joint united ntions Progrmme on Hiv/iDs (unids), nd the us President s emergency Pln for ids relief (PePFr) hve identified mle circumcision to e n essentil prt of Hiv prevention efforts in regions with high rtes of heterosexul trnsmission. 3 Competing interests The uthors declre no competing interests. two mjor ostcles to the implementtion of lrge scle progrms for dult mle circumcision merit considertion: the technicl difficulty of the surgery, nd the ssocited high compliction rte when providers re not properly trined. 10 these fctors hve led to the development of vrious devices for dult mle circumcision, over 20 of which re commercilly ville worldwide. in generl, the mechnism of ction of these devices involves crushing, clmping, or ligture of the foreskin. However, these devices tend to e lrge nd complex to use, nd they lso crete closed environ ment under the foreskin, incresing the risk of infection. Furthermore, discourging results hve een reported in rndomized controlled trils of severl of these devices in dults. use of the tr KLmp (trmedic Corp. sdn. BHD., Kul Lumpur, Mlysi), for exmple, which is used to circumcise children sfely nd success fully in si nd europe, ws ssocited with high rte of dverse events when evluted mong young dults in south fric. 11 the idel device for dult mle circumcision is one tht is sfe nd effective, does not require suturing or electrocutery, nd is simple enough to enle the procedure to e performed y nonphysicin helth cre providers. One device tht might potentilly meet these criteri is the shngring (wuhu snnd Medicl tretment pplince technology Co. Ltd, wuhu City, Chin), which hs een used to circumcise tens of thousnds of men in Chin since the shngring consists of two con centric plstic rings, the inner of which is lined with soft silicone pd, leving smooth, noniorective surfce ginst the surgicl wound. the outer ring consists of two hlves tht re hinged together t one end nd contin locking clsp on the other (Figure 1). these rings re positioned to sndwich the foreskin of the penis llowing it to e excised without stitches or signifi cnt leeding nd re then left in plce for 7 10 dys efore eing removed. while the conventionl dult mle circumcision procedure tkes min to perform, shngring circumcision cn e crried out in round 5 min, enling high numers of procedures to e performed dily. the speed nd simplicity of the technique could mke shngring circumcision n option for use in resource poor settings especilly in environments, such s su shrn fric, where doctors re in short supply nd nonphysicin personnel re the min providers of dult mle circumcision. in this Perspectives, we descrie the shngring surgicl technique nd review the dt nd clinicl experience of its use. Currently, ll pulished dt regrding the shngring re from Chin, where the device ws developed nd is in commercil use. ShngRing surgicl technique Preprtion nd nesthesi ny visile penile lesions secondry to sexully trnsmitted disese, neoplsi, or inflmmtion must e evluted nd treted efore the circumcision. the correct shngring size is scertined using mesuring tpe (provided in the shngring pckge) to determine the penile circumference (Figure 2). pproprite sizing of the device minimizes the risk of its displcement nd of discomfort to the ptient from erections. in the event tht ptient flls etween two sizes, the lrger nture reviews urology DvnCe OnLine PuBLiCtiOn 1

2 Figure 1 The ShngRing is comprised of two concentric plstic rings: n inner ring nd n outer ring. The inner ring is lined with soft silicone pd, leving smooth, noniorective surfce ginst the surgicl wound. The outer ring consists of two hlves tht re hinged together t one end nd contin locking clsp on the other. size should e chosen. no cses of penile necrosis or gngrene due to tight ring hve een reported. shngring circumcision is crried out using sterile technique nd with pproprite locl nesthesi (lidocine 2%). if required, puic hir is shved efore the procedure. stndrd nesthesi involves dorsl penile nerve lock with or without ring lock, lthough no needle nesthesi hs lso een successfully used in shngring circumcision. n explntion of the noneedle nesthesi technique is provided in supplementry Box 1 online. Circumcision technique fter confirming dequte nesthesi, the inner prt of the shngring is plced round the penis to the level of the coronl sulcus (Figure 3). Clmps re plced on the foreskin t the 3, 6, 9 nd 12 o clock positions nd it is then crefully everted over the inner ring (Figure 3). in ptients with phimosis, 1 cm slit is mde in the dorsl prt of the foreskin efore it is everted over the inner ring. next, the outer ring is plced over the inner ring nd is closed to the first stop of the clsp, thus sndwiching the foreskin etween oth rings (Figure 3c). the outer ring is only tightened fter ensuring tht the frenulum is retrcted wy from the outer ring, nd tht symmetricl mrgin of foreskin pproximtely 1.5 cm wide is visile etween the coron of the glns nd the ring. the outer ring is then tightened y locking the clsp t the second stop. the circumcision itself is crried out y excising the excess foreskin using curved scissors (Figure 3d). fterwrds, using sclpel lde, four equidistnt slits re mde in the foreskin on the underside of the proximl surfce of the ring to llow the skin to spred s it hels nd provide spce for expnsion of the sc (Figure 3e). the wound is clened with n ntiseptic solution, dried nd dressed with dry piece of guze. the shngring is left in plce for 7 10 dys (Figure 3f). removl of the Shngring lthough the shngring tkes less thn 3 min to remove, ptients my experience some discomfort during this procedure. For this reson, it is recommended tht ptients tke single dose of n nsid 30 min efore shngring removl. dditionlly, mny prctitioners in Chin pply 1% lidocine to the re round the wound 1 2 min efore the device is removed. the outer ring is unlocked nd removed using the specific shngring removl tool provided in the kit (Figure 4). the inner ring is then gently seprted from the wound mrgin, using scissors tht hve lunt tip nd recessed cutting edges (Figure 4). the wound site is clened with n ntiseptic solution nd wrpped in sterile ndge, which is left in plce for 1 7 dys, ccording to the preference of the surgeon. Postopertive considertions the heling period fter shngring circumcision is pproximtely 4 weeks, during which stinence from sexul ctivity is dvisle. Ptients my the nd return to ll work responsiilities within 24 h of the procedure. Postopertive pin is usully mnged with orl nsids, lthough smll suset of ptients my require 1 2 dys of orl opioid nlgesics, s is Figure 2 Correct sizing of the ShngRing is done using penile circumference mesuring tpe. In the event tht ptient flls etween two sizes, the lrger size should e used. often the cse with stndrd circumcisions. the ptient is dischrged with ndge round his penis, which he chnges s needed. Follow up visits to evlute wound heling demonstrte excellent cosmetic results (Figure 5). sorle suture mterils re used for wound pproximtion in conventionl dult circumcision procedures. lthough they fcilitte effective wound heling, mjor disdvntge of these sutures is tht they leve stitch mrks long the suture line. Circumcision results in penile mucosl edem, which cn e excerted if sorle sutures re plced in the mucocutneous junction, leding to visile suture mrks circumferentilly round the glns penis (Figure 5). Furthermore, sutures cn rek or e disrupted, resulting in wound dehiscence nd further complictions. Postopertive heling of the shngring procedure hs different ppernce to tht of conventionl circumcision, ecuse the wound is sujected to sustined circumferentil pressure nd the skin edges re juxt posed underside to underside rther thn edge to edge. During the 7 10 dys tht the device is left in plce, circumferentil sc forms long the wound surfce. when the shngring is removed, this sc nd pink grnultion tissue is seen round the penis (Figure 6) this is the usul ppernce of wound heling following shngring circum cision nd does not represent dehiscence, lthough it cn seem norml to those fmilir only with suture sed circum cision. no ptient in ll the studies reviewed required dditionl sutures. in ddition, ccording to the Chinese studies, the immune response of the heling re seemed to e roust without ny evidence of incresed risk of wound infections hving een reported. 2 DvnCe OnLine PuBLiCtiOn

3 c d e f Figure 3 The ShngRing procedure. The inner ring is plced round the penis to the level of the coronl sulcus. After plcing clmps on the foreskin t the 3, 6, 9, nd 12 o clock positions, the foreskin is crefully everted over the inner ring. c The outer ring is plced over the inner ring nd closed to the first stop of the clsp, thus sndwiching the foreskin etween oth rings. d The excess foreskin is excised using curved scissors. e Afterwrds, using sclpel lde, 4 slits re mde in the foreskin on the underside of the ring t the 2, 5, 8, nd 11 o clock positions; these slits re necessry to llow the skin to spred s heling occurs nd to llow for expnsion of the sc. f The wound is sujected to sustined circumferentil pressure nd the skin edges re juxtposed underside to underside rther thn edge to edge. The ring is left in plce for round 7 dys. Ptients re informed out potentil complictions of the procedure efore, nd fter, the shngring hs een removed, such s excessive leeding, pin (especilly during erections with the ring in plce), edem, ring displcement, nd infection. dditionlly, ptients should e given instructions on proper hygiene while the device is in plce nd encourged to shower regulrly. they should lso e sked to return to the clinic if they experience excessive pin on erection. the post inflmmtory exudte nd heling sc my resemle n infection or wound dehiscence during the initil period fter the ring hs een removed. the helthcre provider must e mde wre of this fct nd trined to differentite etween the two. fter the shngring is removed, ptients re followed up in the clinic, usully 2 4 weeks postprocedure. Experience with the ShngRing the shngring hs een used in Chin to circumcise oth children nd dults, lthough the vst mjority of shngring circumcisions (including those in the pulished studies, which were ll conducted in Chin) hve een performed in dults ged yers. ll study prticipnts either hd phimosis or desired elective circumcision. Figure 4 Removl of the ShngRing. The outer ring is unlocked nd removed using the ShngRing removl tool. The inner ring is gently seprted from the wound mrgin nd cut t the 3 nd 9 o clock positions using specil scissors tht possess lunt tip nd recessed cutting edges. in the first Chinese study of 1,200 ptients, the verge procedure time ws 3 min (excluding nesthesi). this durtion is sustntilly less thn tht needed for stndrd who recommended circum cision methods. 13 Compliction rtes ssocited with the shngring procedure were low nd included no reports of device disloction or dmge to the frenulum. Mild to moderte edem occurred in 10% of ptients undergoing elective circumcision nd in 3% of those with phimosis. edem of the frenulum ws seen in 2% of ptients, nd the incision ecme infected in <1%. fter removl of the device, wound dehiscence ws oserved in 2% of ptients, nd <1% reported leeding round the incision, which ws treted conservtively with nd ging nd oservtion. nother study of shngring circumcision, which included 328 dult men ged yers, showed tht the men opertive time ws 4.7 ± 1.31 min, with ring removl t 7 8 dys. On scle of 0 10, men pin scores were 0.2 during the circumcision procedure, h postprocedure, 1.7 efore ring removl, nd 2.7 during ring removl. Complictions were mild nd included leeding (2 men), infection (2 men), wound nture reviews urology DvnCe OnLine PuBLiCtiOn 3

4 Figure 5 Penile ppernce following circumcision. Cosmetic result following conventionl circumcision (with sutures). Cosmetic result following ShngRing circumcision. The use of the ShngRing does not result in the scrs often seen with conventionl circumcision technique. Figure 6 When the ShngRing is removed, helthy pink grnultion tissue encircles the penis. Although the ppernce of the wound is quite different from tht seen fter conventionl circumcision, this ppernce does not suggest infection or dehiscence. edem (16 men), nd wound dehiscence (2 men), ll of whom were mnged conservtively. the men time for complete wound heling ws 20.3 dys. 99.7% of men were stisfied with the cosmetic result nd 73.2% were sexully ctive 1 month fter shngring circumcision. 14 in further study, 60 men underwent shngring circumcision using the noneedle nesthesi technique (supplementry Box 1 online). 15,16 the men ge of ptients in this study ws 25.4 yers. the medin time to onset of the nesthetic effect ws 42 s. Of the 60 men receiving nesthesi vi jet injection, nine (15%) required supplementl needle nesthesi ( penile ring lock using 3 5 ml of 1% lidocine) efore proceeding with the circumcision. Complictions ssocited with use of noneedle nesthesi involved mild urethrl leeding in four ptients, which resolved spontneously with mild pressure t the jet injector site in ll cses. Further discussion of jet injector nesthesi per se is outside the scope of this Perspectives, however this method of nesthesi is vile option to e used in resource poor res, s it cn e used y nonphysicin helth cre providers, if they re properly trined. prospective, noncomprtive study crried out in Keny ws designed to ssess the sfety, efficcy nd cceptility of shngring circumcision in dult men. 17 three people (one ostetricin/gynecologist, one surgeon, nd one nurse) underwent stndrdized trining progrm in the shngring circumcision technique. Following informed consent nd penile ring lock, 40 Hiv negtive Kenyn men underwent shngring circumcision, crried out y the newly trined physicin or nurse. Follow up included clinicl exmintions t 2, 7, 9, 14, 21, 28, 35 nd 42 dys fter circumcision to ssess device plcement, occurrence of dverse events, nd heling progress, s well s ptient reported prolems nd levels of stisfction. the shngring ws removed on dy 7 in ll ptients. the verge procedure time for circumcision nd device removl ws 4 5 min nd no intropertive complictions were reported. six ptients reported mild postopertive dverse events, including minor injuries to the penile skin (three men), moderte edem (two men), nd infection (one mn), ll of which resolved with conservtive mngement. three prtil detchments of the shngring device occurred t dys 2 7, lthough they did not require tretment or erly ring removl. erections with the shngring in plce were well tolerted, with men pin score of 3.5 ± 2.3. pproximtely 85% of men were ck t work y dy 7 fter surgery. t 7 dys, 90% of prticipnts were very stisfied nd the remining 10% were somewht stisfied with their circumcision. ll prticipnts sid they would recommend the shngring procedure to others. the preliminry results of this study the first to e conducted outside Chin re encourging, nd indicte tht the shngring is suitle for further study in fricn popul tions. 17 use of shngring circumcision could potentilly increse tke up rtes of dult mle circumcision, especilly in res where Hiv is endemic. the fricn study correltes well with results from Chin. ll of the trils to dte show tht the shngring is suitle device for dult mle circum cision, lthough dditionl study is wrrnted in fricn popultions. the studies lso show tht the device hs some dvntges over conventionl circum cision pproches, such s eing fster nd hving reduced risk of leeding. Discussion surgicl complictions of circumcision include excessive leeding, hemtom form tion, infection, pin, injury to the glns or urethr, excessive or insufficient skin removl, nd poor cosmetic results. Current compliction rtes for dult mle circum cision re out 2 4% under optiml condi tions, 3,18,19 ut re considerly higher in resource poor settings nd when circumcision is performed y inexperi enced or poorly trined prcti tioners. study conducted in Keny hs demon strted tht circum cision compliction rtes rnge from 17% in clinicl settings to 35% in trditionl settings. 20 Despite the potentil enefits of circum cision in reducing trnsmission of Hiv in res where infection with this virus is endemic, the stndrdiztion of dult mle circum cision is n ongoing issue. extensive trining nd resources re, therefore, required in su shrn fric, where dult mle circum cision is eing ggressively promoted. the existing evidence indictes tht shngring circumcision is sfe nd effective in dult men. dvntges of the shngring procedure over the trditionl suture technique include its simplicity nd short durtion (round 5 min compred to the min required for conventionl circum cision). the coronl sulcus is visile throughout the procedure, minimizing the risk of injury to the glns (Figure 3). the sterile device forms tight sel long the wound, which mintins hemostsis without the need for sutures nd llows ptients to shower or the normlly immeditely fter the procedure. the sutureless closure hels well with excellent cosmetic results. these chrcteristics men tht shngring circum cision hs the potentil to e used in high volume, resource poor settings, y helth cre providers with miniml levels of trining nd experience. Millions of dult mle circumcisions hve een estimted to e required over the next 5 10 yers to effectively slow the spred of Hiv. 21,22 in fric, dult mle circumcision is usully performed using methods recommended y the who, 23 which include forceps guided, dorsl slit, or sleeveresection methods. dult mle circum cision hs suffered from derth of reserch compring the different surgicl techniques nd devices ville. the shngring is one of few dult mle circumcision devices tht hs een studied in lrge popultions. 12,14 mjor disdvntge of the shngring is the necessity for men to wer the ring for 4 DvnCe OnLine PuBLiCtiOn

5 7 dys. in ddition, second visit to the clinic is required for ring removl. However, this visit cn e n dvntge s it fcilittes postsurgicl evlution of the ptient nd provides n opportunity to reinforce dvice given in Hiv risk reduction counseling. Concerns hve een rised tht ptients might not return for their postopertive device removl visit nd, therefore, might e sujected to dverse events s consequence of device retention. to dte, no studies hve investigted this possiility, lthough proposls re in plce to investi gte vrious intervls for device removl in order to explore whether ny dditionl enefit or hrm is experienced y ptients who retin the device for >7 dys. Despite these concerns, few reports of dverse consequences regrding the length of time the ring is left in plce were mentioned in either the Chinese or fricn studies, nd ptients were llowed to the nd resume ll norml ctivities (except for sexul ctivity) immeditely fter the shngring circumcision. the unique shngring kits required to pply nd remove the device, s well s the need to stock multiple sizes of the shngring, my lso prove to e limittion to their use, lthough experience with using the shngring in Chin hs not suggested tht these fctors cuse prolems. Further trils could collect dt on the most commonly used sizes to enle helth services to predict the numer of sizes required for future scled up efforts. stndrd surgicl circumcision does hve the enefit of using instruments tht cn e used for other proce dures, thus the equipment is lredy on hnd nd costs re reduced. the overll cost of shngring dult mle circumcision in fric is currently unknown, s the devices used in the Kenyn study were donted for reserch purposes. in Chin, the shngring sells for out rmb per kit, which equtes to pproximtely us$ this price includes one shngring set, the mesuring tpe, nd 10 ndges. However, the ctul cost of production of the ring is much lower nd negotitions re under wy with the mnufcturer to determine significntly reduced price for the pulic sector in resource poor settings such s su shrn fric. Once demnd for shngring circum cisions in fric hs een estlished, cost enefit nlysis of the procedure s efficcy in terms of Hiv prevention will need to e undertken. Future plnned studies of the shngring procedure include prospective, rndomized, controlled trils to compre it to conventionl surgicl techniques nd to determine the idel time for device removl. dditionlly, studies compring the use of the no needle (jet injector) nesthesi technique to tht of trditionl needle nesthesi in shngring circum cision re plnned. Conclusions the shngring is simple nd effective device for dult mle circumcision. its use results in sustntilly reduced opertive times nd compliction rtes versus suturesed circumcision, s demonstrted y studies in Chin nd Keny. dditionlly, the simplicity of its ppliction nd removl men tht use of the device cn e tught to nonphysicin helth cre providers, which suggests tht shngring circum cision would e vlule option for use in resourcepoor settings. these chrcter istics could increse rtes of dult mle circum cision in Hiv endemic countries where circum cision prevlence is currently low. Center for Mle Reproductive Medicine nd Surgery; Deprtment of Urology, nd the Institute for Reproductive Medicine, Weill Cornell Medicl College of Cornell University, 525 Est 68 th Street, New York, NY , USA (P. Msson, P. S. Li, M. Goldstein). The Popultion Council, One Dg Hmmrskjold Plz, 9 th Floor, New York, NY 10017, USA (M. Goldstein). EngenderHelth, 440 Ninth Avenue, New York, NY 10001, USA (M. A. Brone). Correspondence to: M. Goldstein mgoldst@med.cornell.edu 1. Willims, N. & Kpil, L. Complictions of circumcision. Br. J. Surg. 80, (1993). 2. Crwford, D. A. Circumcision: considertion of some of the controversy. J. Child. Helth Cre 6, (2002). 3. World Helth Orgniztion, Deprtment of Reproductive Helth nd Reserch nd Joint United Ntions Progrmme on HIV/AIDS (UNAIDS). Mle circumcision: glol trends nd determinnts of prevlence, sfety nd cceptility (WHO Press 2007). 4. Hlperin, D. T. & Biley, R. C. Mle circumcision nd HIV infection: ten yers nd counting. Lncet 354, (1999). 5. Auvert, B. et l. effect of mle circumcision on the prevlence of high-risk humn ppillomvirus in young men: results of rndomized controlled tril conducted in Ornge Frm, South Afric. J. Infect. Dis. 199, (2009). 6. Toin, A. A. et l. Mle circumcision for the prevention of HSV-2 nd HPV infections nd syphilis. N. Engl. J. Med. 360, (2009). 7. Biley, R. C. et l. Mle circumcision for HIV prevention in young men in Kisumu, Keny: rndomised controlled tril. Lncet 369, (2007). 8. Gry, R. H. et l. Mle circumcision for HIV prevention in men in Rki, Ugnd: rndomised tril. Lncet 369, (2007). 9. Auvert, B. et l. Rndomized, controlled intervention tril of mle circumcision for reduction of HIV infection risk: the ANRS 1265 Tril. PLoS Med. 2, e298 (2005). 10. Kim, H. H. & Goldstein, M. High compliction rtes chllenge the implementtion of mle circumcision for HIV prevention in Afric. Nt. Clin. Prct. Urol. 6, (2009). 11. Lgrde, e., Tljrd, D., Puren, A. & Auvert, B. High rte of dverse events following circumcision of young mle dults with the Tr KLmp technique: rndomized tril in South Afric. S. Afr. Med. J. 99, (2009). 12. Peng, Y. F. et l. Clinicl ppliction of new device for minimlly invsive circumcision. Asin J. Androl. 10, (2008). 13. WHO, UNAIDS, JHPIeGO. Mnul for Mle Circumcision under Locl Anesthesi Version 2.5C [online], mlecircumcision/locl_nesthesi/en/ index.html (2008). 14. Cheng, Y. et l. A recommendle stndrd protocol of dult mle circumcision with the Chinese Shng Ring: outcomes of 328 cses in Chin [Chinese]. Zhonghu Nn Ke Xue. 15, (2009). 15. Weiss, R. S. & Li, P. S. No-needle jet nesthetic technique for no-sclpel vsectomy. J. Urol. 173, (2005). 16. Peng, Y. F. et l. No-needle locl nesthesi for dult mle circumcision. J. Urol. 184, (2010). 17. Brone, M. A. et l. Pilot study of the Shng Ring: novel mle circumcision device for HIV prevention. Presented t the 18 th Interntionl AIDS Conference (2010). 18. Krieger, J. N. et l. Adult mle circumcision: results of stndrdized procedure in Kisumu District, Keny. BJU Int. 96, (2005). 19. Krieger, J. N. et l. Adult mle circumcision outcomes: experience in developing country setting. Urol. Int. 78, (2007). 20. Biley, R. C., egesh, O. & Rosenerg, S. Mle circumcision for HIV prevention: prospective study of complictions in clinicl nd trditionl settings in Bungom, Keny. Bull. World Helth Orgn. 86, (2008). 21. Willims, B. G. et l. The potentil impct of mle circumcision on HIV in Su-Shrn Afric. PLoS Med. 7, e262, (2006). 22. UNAIDS/WHO/SACeMA expert Group on Modelling the Impct nd Cost of Mle Circumcision for HIV Prevention. Mle circumcision for HIV prevention in high HIV prevlence settings: wht cn mthemticl modelling contriute to informed decision mking? PLoS Med. 9, e (2009). 23. Liu, W. S. & Wong, K. C. in Clinicl Anesthesi 2 nd edn (eds Brsh, P. G., Cullen, B. F. & Stoelting, R. K.) (Lippincott, Phildelphi, 1992). Acknowledgments The uthors would like to thnk Y. Peng nd Y. Chng for their work using the ShngRing in Chin nd for shring their clinicl experiences with us. Author contriutions All uthors reserched dt for the rticle nd were involved in discussion of content, s well s writing nd reviewing nd editing the mnuscript efore sumission. Supplementry informtion Supplementry informtion is linked to the online version of this pper t nture reviews urology DvnCe OnLine PuBLiCtiOn 5