Time spent on the waiting list due to graft size incompatibility

Transcription

1 Cdveric Lobr Lung Trnsplnttion: Technicl Aspects Silvn F. Mrsco, FRACS, Stephnie Thn, Dominic Keting, FRACP, Glen Westll, FRACP, Helen Whitford, FRACP, Greg Snell, FRACP, Julin Gooi, FRACS, Trevor Willims, FRACP, Adrin Pick, FRACS, Adm Zimmet, FRACS, nd Gerldine A. Lee, MPhil Crdiothorcic Surgery Unit, nd Deprtment of Respirtory Medicine, The Alfred Hospitl, Prhn, Victori; nd Deprtment of Surgery, Monsh University, Melbourne, Victori, Austrli Bckground. The use of lobr trnsplnttion nd other size reduction techniques hs llowed lrger donor lungs to be utilized for smller recipients who tend to hve longer witing times for trnsplnttion. However, despite these dvntges, the techniques hve not been widely dopted. We outline the surgicl nd sizing issues ssocited with this technique. Methods. A retrospective review of 23 consecutive ptients who received lung trnsplnttion with ntomic lobr reduction ws performed, focusing on surgicl technique nd outcomes. Results. All 23 ptients received n ntomic lobr reduction of between 1 nd 3 lobes. Survivl nlysis showed no difference between the lobr reduction cohort nd the other historiclly comprble lung trnsplnt ptients from our institution (p 0.115). Percent predicted forced vitl cpcity nd forced expirtory volume in 1 second t 3 months correlted with trnsplnted donor to recipient totl lung cpcity rtio, confirming the importnce of correct sizing. Conclusions. Antomic lobr reduction in lung trnsplnttion is sfe nd effective mens of trnsplnting peditric nd smll dult recipients, nd urgently listed ptients. (Ann Thorc Surg 2012;93: ) 2012 by The Society of Thorcic Surgeons Time spent on the witing list due to grft size incomptibility issues cn often be prolonged nd detrimentl for peditric ptients nd smll dults in urgent need of trnsplnttion [1]. In ddition, sicker ptients in need of urgent trnsplnttion do not lwys hve the luxury of witing for size-mtched orgns. There re lso instnces during surgery when donor lungs re lrger thn expected for the recipient nd size reduction is required for n idel fit. The use of lobr trnsplnttion, nonntomic cut down, nd split lung trnsplnttion hve llowed lrger donor lungs to be downsized for use in smller recipients, nd for urgent trnsplnttion in non size-mtched individuls [2]. However, despite these dvntges, the techniques hve not been widely dopted. The use of lobr trnsplnttion ws first described in living lobr donors in 1994 [3]. Severl yers lter, lung tiloring (nonperipherl segmentl resections) ws described to overcome size discrepncies in cdveric donors [4]. Since then, there hs been rpid expnsion of reports of living-relted lobr trnsplnttion but much smller number of published experiences with cdveric lobr trnsplnttion [3, 5 11]. We hve previously reported our outcomes with smller cohort of lobr lung trnsplnts [11]. The im of this report ws to updte our Accepted for publiction Mrch 20, Address correspondence to Dr Mrsco, Deprtment of Surgery, The Alfred Hospitl, Commercil Rd, Prhrn, Victori, Austrli 3181; e-mil: s.mrsco@lfred.org.u. experience with cdveric lobr lung trnsplnttion nd lso to provide description of the surgicl nd sizing issues ssocited with this technique. We hope tht this will encourge other units to consider performing lobr trnsplnttion for their urgently listed cndidtes nd smller dult nd peditric witing list ptients. Ptients nd Methods Since the inception of our lung trnsplnt progrm in 1990 to the end of Februry 2012, we hve performed 885 lung trnsplnts. Of these, 569 bilterl sequentil, 253 single, nd 63 hert-lung trnsplnts hve been performed. In 2005, in n effort to improve the witing list servicing of smller recipients, we decided to perform lobr trnsplnttion in select group of recipients when size mismtching occurred. Since then, we hve become the ntionl peditric lung trnsplnt center nd hve used size-reduced orgns for those recipients. More recently, we hve expnded the utiliztion of lobr trnsplnt for urgent (inptient) cndidtes who do not lwys hve the luxury of witing for size-mtched orgns. Since then, 23 ptients hve received reduced size lungs by ntomic lobectomy (6.7% of the totl lung trnsplnts over tht period). These 23 ptients form the bsis of this report (Tble 1). Dt were prospectively collected on ll ptients nd entered into our trnsplnt dtbse. Retrospective chrt review ws lso undertken; censor dte for survivl ws tken on Februry 29, Ptients t 2012 by The Society of Thorcic Surgeons /$36.00 Published by Elsevier Inc doi: /j.thorcsur

2 Ann Thorc Surg MARASCO ET AL 2012;93: CADAVERIC LOBAR LUNG TRANSPLANTATION Abbrevitions nd Acronyms BSL bilterl sequentil lung trnsplnt CPB crdiopulmonry bypss CXR chest X-ry D/R donor to recipient ECMO extrcorporel membrne oxygention FEV 1 forced expirtory volume in 1 second FVC forced vitl cpcity LLL left lower lobe of lung MMEF mximl mid expirtory flow PGD primry grft dysfunction RLL right lower lobe of lung RML right middle lobe RUL right upper lobe SL single lung trnsplnt TLC totl lung cpcity our institution re consented for the use of lobr trnsplnt nd mrginl orgns when they re listed. Institutionl ethics pprovl ws grnted nd requirement for specific ptient consent for inclusion in this retrospective review ws wived. Orgns re mtched by ABO comptibility, prospective donor-specific T cell crossmtch, nd size. Size mesurements re bsed on ptient height nd weight, submmmry chest dimeter on chest X-ry, nd height of lung on ech side by chest X-ry. Predicted nd ctul totl lung cpcities (TLC) re vilble for recipients nd nomogrms re used to predict donor TLC. In the ptients in this series, lrger donors were ccepted for our peditric recipients nd for size-mismtched dult recipients who were deteriorting on the witing list nd needed trnsplnttion urgently. Predicted TLC ws clculted bsed on the stndrdiztion of the Europen Respirtory Society, where TLC predicted for mle ptients 7.99 (height in meters) 7.08 nd for femle ptients 6.60 (height in meters) 5.79 [12, 13]. For peditric femle ptients, the following eqution ws used [14]: ge (yers) height (cm) weight (kg) (3, ) 1,000. There were no mle peditric ptients in this series. lung preservtion consisted of 5.6 L ntegrde flush of cold Perfdex (Vitrolife, Inc). The lungs were then stored in Perfdex nd trnsported on ice. At the time of implnttion the lungs were given mnul retrogrde flush to remove clots nd other emboli such s ft. Immunosuppression included stndrd triple-drug therpy with corticosteroids, zthioprine or mycophenolte mofetil, nd cyclosporine or tcrolimus. Ischemic time ws defined s the time from cross clmping of the ort in the donor until relese of the pulmonry rteril clmp in the recipient. Where bilterl sequentil lung trnsplnt ws performed, the time of relese of the second pulmonry rteril clmp ws tken s the end of the donor orgn ischemic time. Surgicl Technique As cn be seen from Tble 1, ll except 1 ptient in this series received bilterl sequentil lung trnsplnttion. Our stndrd technique for this opertion hs been to perform the surgery through clmshell incision through the fourth intercostl spce with trnsverse sternotomy. Ptients re given 5,000 U heprin prior to clmping the hilr vsculr structures. Crdiopulmonry bypss (CPB) is voided whenever possible. All ptients in this series received n ntomic lobectomy rther thn peripherl segment resection or nonntomic stpled resection. Lobr reduction cn be performed on the bck tble before or in situ fter implnttion of the lung. The choice of which lobe to resect is bsed on technicl nd pthologicl fctors. Technicl issues such s the mount of volume to be removed nd the re in the chest cvity where the volume is excessive need to be considered. A middle lobectomy, for exmple, will reduce lung volume in the nteroposterior dimeter nd is useful in slender ptients with nrrow nteroposterior dimeters. A lower lobectomy is useful in ptients with short chest cvity or reltively rised diphrgm, such s pulmonry fibrosis ptients. An upper lobectomy will lso reduce volume, especilly in the verticl spect, but this leves the vst mjority of the lung prenchym below the hilum with potentil picl spce. Leving potentil bsl spce is esier to del with s the diphrgm will rise to fill tht spce. At times the choice of which lobe to remove hs been bsed on pthologicl fctors such s severe contusion in lower lobe or scrring nd blebs t the pex of donor upper lobe. Our decision to perform the lobr size reduction is bsed ultimtely on visul ssessment of the size discrepncy t the time of surgery. However, cse my be flgged s potentilly needing lobr reduction bsed on donor to recipient (D/R) weight discrepncy of more thn 15% or D/R predicted TLC discrepncy of more thn 15% to 20%. We hve not found tht size discrepncies less thn this led to ny significnt postopertive problems nd for this reson we rrely perform stpled peripherl wedge resections. Sttisticl Anlysis Anlysis ws conducted using Stt 11.0 (SttCorp LP, TX). The Spermn rnk correltion ws used to exmine the reltionship between 2 numeric vribles tht were not normlly distributed. Acturil survivl of ptients ws presented using Kpln-Meier curves with p vlues clculted using log-rnk tests. A 2-sided p vlue less thn 0.05 ws considered to be sttisticlly significnt. Results 1837 Anlysis of the TLC rtio between donors nd recipients shows vrition from 0% to 300% discrepncy (Tble 1). Eight ptients hd predicted TLC discrepncy of less thn 20%, but the recipient chest cvity size mndted lobr reduction. These ptients tended to hve either bronchiectsis or pulmonry fibrosis. The lobectomies performed re outlined in Tble 2. Thirteen ptients required CPB during the opertion, instituted for vriety of resons including wke insti-

3 1838 MARASCO ET AL Ann Thorc Surg CADAVERIC LOBAR LUNG TRANSPLANTATION 2012;93: Tble 1. Ptient Demogrphics Ptient No. Age Gender Dignosis Predicted TLC Actul TLC Preop Age Gender Cuse of Deth Predicted TLC D/R Weight Rtio D/R Height Rtio 1 37 F Cystic fibrosis M CVA F Emphysem M CVA M Pulmonry fibrosis M CVA F Emphysem M Anoxi F Primry pulmonry M CVA hypertension 6 46 F Oblitertive M Anoxi F Oblitertive M CVA F Cystic fibrosis F Anoxi F Emphysem M Trum F Oblitertive F Anoxi F Oblitertive M Trum M Bronchiectsis M Trum F Asthm M CVA F Cystic fibrosis M Trum F Bronchiectsis F CVA M Pulmonry fibrosis M CVA M Pulmonry fibrosis M Trum M Cystic fibrosis M CVA F Primry pulmonry F Anoxi hypertension F Emphysem M Anoxi F Primry pulmonry M Anoxi hypertension M Pulmonry fibrosis M CVA M Oblitertive M Trum Missing dt. CVA cerebrl vsculr ccident; D/R donor to recipient; TLC totl lung cpcity. tution of peripherl CPB due to severe pulmonry hypertension, circultory instbility, difficulty oxygenting the ptient, nd to protect the lobr implnt. Ptient 11 ws trnsplnted on extrcorporel membrne oxygention (instituted more thn 2 weeks prior) which ws successfully wened pproximtely 12 hours postopertively. Fifty-six percent of the lobr reduction cohort required CPB or extrcorporel membrne oxygention for trnsplnttion (compred with 13.4% of our non lobr reduction group). Tble 2 outlines the timing of the lobectomies. The peditric ptients (Nos. 7, 8, 10, nd 11) tended to hve their lobectomies performed on the bck tble prior to implnttion. The verge opertive time for the entire cohort ws minutes. There were 3 complictions directly relted to the lobr size reduction. One occurred in ptient 12 who ws severely mlnourished t the time of his surgery. He developed stump lek t the site of the right lower lobectomy nd required thorcotomy with direct oversewn nd intercostl muscle flp to repir the lek. Ptient 16 developed left min bronchus stricture presumbly due to ischemi nd required stenting. Ptient 21 ws found to hve kink t the left min bronchil nstomosis which required revision surgery 48 hours fter trnsplnt. The primry grft dysfunction grde in the first 24 hours ws ssessed but no correltion ws found with the timing (bck tble versus postimplnttion) or side of the size reduction. All ptients who required CPB or extrcorporel membrne oxygention developed t lest grde 2 3 primry grft dysfunction. Interestingly the 3 peditric ptients who did not require CPB showed the lest degree of postopertive primry grft dysfunction (ll grde 0 1). ctul nd predicted TLC is reported in Tble 1. Some ptients (usully interhospitl trnsfers) do not hve ctul TLC recorded. The percentge of lung volume removed ws clculted using the percentges ssigned to ech lobe s reported by Mueller nd collegues [7], nd ws used to clculte n estimte of the ctul trnsplnted TLC in ech recipient (Tble 2). The plnned lobr reductions tended to hve more lung

4 Ann Thorc Surg MARASCO ET AL 2012;93: CADAVERIC LOBAR LUNG TRANSPLANTATION Tble 2. Opertive Dt Ptient No. Lung Trnsplnt Performed Lobectomy Performed Plnned Size Reduction CPB Bck Tble Lobectomy Right Side Bck Tble Lobectomy Left Side Ischemic Time Right Lung Ischemic Time Left Lung 1839 Trnsplnted D/R TLC Rtio 1 BSL RLL, LLL Y Y N Y SL LLL N N N BSL RML N N N BSL RML N N N BSL RLL, LLL N N N N BSL LLL N N Y BSL RLL, LLL Y N Y Y BSL RLL, LLL Y N N Y BSL LLL N Y N BSL RLL, LLL Y N Y Y BSL RUL, RML, LLL Y Y Y Y BSL RLL, LLL N Y N Y BSL RLL, LLL Y Y N Y BSL RML, LLL Y Y N N BSL RML N N N BSL LLL Y Y Y BSL RLL, LLL Y N Y Y BSL RUL, RML Y Y Y BSL RML, LLL N Y N Y BSL RLL, LLL N Y Y Y BSL LLL N Y Y BSL LLL N Y N Y BSL RML, LLL N Y N N Not pplicble. BSL bilterl sequentil trnsplnt; CPB crdiopulmonry bypss; D/R TLC donor to recipient totl lung cpcity; LLL left lower lobe; RLL right lower lobe; RML right middle lobe; RUL right upper lobe; SL single lung trnsplnt. tissue removed thn the unplnned reductions. All of the peditric lobr trnsplnts were plnned prior to commencement of surgery. Medin intensive cre unit sty ws 12 dys (rnge 2 to 113 dys) compred with the historiclly comprble non lobr reduction cohort of 4 dys (rnge 2 to 51); NS. Medin hospitl sty ws 30 dys (rnge 10 to 191), which gin ws longer thn the non lobr reduction cohort, but not significntly so [21 dys (rnge 2 to 373)]. Lung function testing t 3 nd 6 months reveled percent predicted forced expirtory volume in 1 second (FEV 1 ) (men SD of entire group) of nd , nd percent predicted forced vitl cpcity (FVC) (men SD) of nd Twelve-month dt re not presented s they were vilble on only 8 ptients. Anlysis of the lung function test results t 3 months postopertively showed correltion between % predicted FEV 1 nd D/R trnsplnted TLC rtio (r 0.52; p 0.019) (Fig 1) nd between % predicted FVC nd D/R trnsplnted TLC rtio (r 0.54; p 0.015) (Fig 2). Percent predicted FEV 1 nd D/R trnsplnted TLC rtio lso correlted t 6 months (r 0.549; p 0.028). Ten of the 23 lobr reduction ptients were inptients t the time of their trnsplnt. In 7 of the inptients it ws felt they would not survive to leve hospitl without trnsplnttion. Survivl nlysis shows no significnt difference between this lobr reduction cohort nd the other historiclly comprble lung trnsplnt ptients from our institution (p 0.115) (Fig 3). Of the 9 ptients who hve died to dte, 4 were in this urgent inptient subgroup. The cuses of deth hve been obliterns in 2 ptients, sepsis in 2 ptients, mlignncy in 1 ptient (fter third-time trnsplnt), cerebrovsculr ccident in 1 ptient, noxic brin injury in nother ptient, nd nonspecific grft filure in 2 ptients. Two of these deths were inptient deths (both neurologic deths). Comment The use of cdveric lobr trnsplnt is not widespred, despite the dvntges this gives to size disdvntged nd urgent witing list cndidtes. The published literture consists of only few cse series of cdveric lobr trnsplnts, most of which hve been performed in high volume lung trnsplnt centers [3, 5 11]. We hve demonstrted correltion between trnsplnted D/R TLC rtio nd both % predicted FVC nd FEV 1. This hs not been previously reported in cdveric lobr trnsplnt series. This result does demonstrte the importnce of correct size mtching. Clerly those ptients in whom too

5 1840 MARASCO ET AL Ann Thorc Surg CADAVERIC LOBAR LUNG TRANSPLANTATION 2012;93: Fig 1. Spermn correltion of % predicted forced expirtory volume in forced expirtory volume in 1 second (FEV 1 ) nd trnsplnted donor to recipient (D/R) totl lung cpcity (TLC) rtio. R s sttistic 0.52; p much lung prenchym ws removed hd significntly reduced lung function. In contrst n excessively oversized grft hs been shown to result in telectsis, impired diphrgm movement, elevted pulmonry vsculr resistnce, nd poor gs exchnge [15]. An oversized grft essentilly mimics the respirtory compromise seen in hyperventilted emphysemtous ptients, whereby chest wll nd diphrgmtic movements re impired. Thus, correct size mtching is of prmount importnce. There re dvntges nd disdvntges to ech of the techniques; bck tble versus postimplnttion lobectomy. The dvntge of the bck tble technique is tht the lobectomy cn be performed by second surgeon, minimizing cold ischemic time. It is lso useful in very smll ptients where implnttion of the whole lung in the first instnce would obscure the view of the hilum becuse of the gross size mismtch. Thus, our peditric ptients ll hd bck tble lobectomies. The disdvntge of this technique is tht it cn be techniclly difficult. None of the vessels re distended by blood nd ll the structures pper white, mking it difficult to identify nd seprte veins from rteries. The lobectomy performed is ntomic, leving the hilr structures intct so tht the hilr nstomoses re completed in the sme fshion s is done when the entire lung is implnted. Lobectomy fter implnttion cn cuse difficulties with visuliztion if there is lot of lung prenchym in very smll chest. If performing the trnsplnt without crdiopulmonry bypss, it is better to implnt both Fig 2. Spermn correltion of % predicted forced vitl cpcity (FVC) nd trnsplnted donor to recipient (D/R) totl lung cpcity (TLC) rtio. R s sttistic 0.54; p

6 Ann Thorc Surg MARASCO ET AL 2012;93: CADAVERIC LOBAR LUNG TRANSPLANTATION 1841 Fig 3. Survivl curve Kpln-Meier nlysis; p lungs before performing ny size reduction. This is becuse the pulmonry rtery to the contrlterl lung will be clmped during the next stge of the trnsplnt, sending the entire crdic output through the newly implnted lung. To send the entire crdic output through newly implnted lobe lone would be more likely to precipitte reperfusion injury nd should be voided. Once the second lung is implnted, both lungs cn be observed fully ventilted nd decision to proceed with the lobectomy mde t tht time. The risk of reperfusion edem due to high flow is less in the peditric ptients becuse of their smller circulting volume, nd thus bck tble lobectomy is pproprite in those ptients. In contrst to the bck tble lobectomy, lobr size reduction once the entire lung is implnted cn be esier s it is reltively simple to identify the distended vsculr structures. The lung is lso fixed by its ttchment to the hilum mking it esier to work on it with miniml ssistnce. The difficulties t this stge cn be edem if there is some reperfusion injury developing, mking the tissues frgile nd the lung prenchym prone to tering. Complete fissures t this stge re most welcome ntomic vrint. Historiclly, the most common type of lobr trnsplnt performed worldwide hs been living-relted lobr trnsplnt [16 18]. Much of our current knowledge of cdveric lobr trnsplnttion hs stemmed from interntionl experience with this opertion. Numerous studies hve reported cceptble erly opertive outcomes, functionl outcomes, nd survivl in recipients of livingrelted lung trnsplnttion [16 18]. More recently, longer term functionl outcomes hve lso been shown to be comprble with cdveric trnsplnttion [18]. Tht study by Bowdish nd collegues showed tht the men percent predicted FVC nd FEV 1 were lower t 1 nd 3 months postopertively in the lobr recipients compred with concurrent cohort of dult bilterl cdveric lung trnsplnts, lthough the vlues were comprble between groups t 6 months. The uthors lso found reduced men predicted forced expirtory flow between 25% nd 75% of vitl cpcity t 1 month postopertively in the lobr group compred with the cdveric group. They hve postulted tht this erly reduced pulmonry function my be result of ltered pulmonry mechnics whereby the lobe is not perfectly opposed to the chest wll. Over time, s lveolr dilttion nd recruitment of the grft occurs, s well s remodeling of the chest wll, better pposition in this pleurl spce occurs nd lung mechnics lso improve. It hs been demonstrted in cnine living donor lobr lung trnsplnt model tht excessively undersizing donor lung llogrfts results in elevtion of pulmonry rtery pressures, depression of prtil pressure of oxygen, nd cute lung edem [19]. Three of our ptients hd complictions t the bronchil nstomosis where lobr reduction hd occurred. After trnsplnttion, the bility of the bronchil nstomosis to hel is lrgely dependent on retrogrde flow from the implnted pulmonry vsculr tree rther thn on ntegrde bronchil blood supply. Thus, further disruption of this retrogrde blood supply by trnsecting prt of the bronchil nd vsculr tree during lobr trnsplnt is likely to increse the risk of bronchil nstomotic problems. Other uthors hve lso noted bronchil nstomotic problems in lobr trnsplnttion lthough the incidence ws not significntly different to their comprison groups [6, 8]. We perform end-to-end bronchil nstomoses in our non lobr reduction group nd hve very low incidence of bronchil complictions with tht technique (less thn 1%). Most of the complictions tend to be overgrnultion, which is treted with lser therpy. The bronchil complictions seen in our lobr trnsplnt group seem to be more specific to the lobr trnsplnt technique nd re occurring t much

7 1842 MARASCO ET AL Ann Thorc Surg CADAVERIC LOBAR LUNG TRANSPLANTATION 2012;93: higher rte (13%). We hve lso noted tht those ptients who hve hd left lower lobectomy seem to be prone to some nrrowing or kinking of the left upper lobe bronchus s the upper lobe rottes inferiorly to fill the pleurl spce. This my be relted to excessive volume being removed. The survivl of our lobr trnsplnt group ws comprble with our overll ptient cohort over the first 18 months posttrnsplnt nd then the curves diverged with worse results in the lobr trnsplnt group, lthough this ws not sttisticlly significnt. It is possible tht this represents sicker group of ptients who were unble to wit for size-mtched orgns. This is evidenced by the higher number of inptients nd the incresed use of CPB in this lobr reduction cohort. However, the numbers re so smll fter 18 months follow-up tht it is impossible to drw ny conclusions bout the longer term outcomes. In conclusion, we hve shown tht cdveric lobr lung trnsplnttion is useful strtegy in n lredy estblished lung trnsplnttion center in order to ddress the pucity of orgns vilble for ptients with smller lung sizes, nd for sicker ptients who cnnot wit for sizemtched orgns. We hve demonstrted correltion between lung function nd trnsplnted D/R TLC rtio, indicting tht incorrect sizing, prticulrly undersizing, does hve n impct on postopertive function. References 1. Sweet SC. Peditric living donor lobr lung trnsplnttion. Peditr Trnsplnt 2006;10: Aigner C, Mzhr S, Jksch P, et l. Lobr trnsplnttion, split lung trnsplnttion nd peripherl segmentl resection Relible procedures for downsizing donor lungs. Eur J Crdiothorc Surg 2004;25: Strnes VA, Brr ML, Cohen RG. Lobr trnsplnttion: Indictions, technique, nd outcome. J Thorc Crdiovsc Surg 1994;108: Wisser W, Klepetko W, Wekerle T, et l. Tiloring of the lung to overcome size disprities in lung trnsplnttion. J Hert Lung Trnsplnt 1996;15: Sntos F, Lm R, Alvrez A, et l. Pulmonry tiloring nd lobr trnsplnttion to overcome size disprities in lung trnsplnttion. Trnsplnt Proc 2005;37: Aigner C, Winkler G, Jksch P, et l. Size-reduced lung trnsplnttion: An dvnced opertive strtegy to llevite donor orgn shortge. Trnsplnt Proc 2004;36: Couetil J-PA, Toln MJ, Loulmet DF, et l. Pulmonry biprtitioning nd lobr trnsplnttion: new pproch to donor orgn shortge. J Thorc Crdiovsc Surg 1997;113: Mueller C, Hnsen G, Bllmnn M, et l. Size reduction of donor orgns in peditric lung trnsplnttion. Peditr Trnsplnt 2010;14: Artemiou O, Weiselthler G, Zuckermnn A, et l. Downsizing of the donor lung: peripherl segmentl resections nd lobr trnsplnttion. Trnsplnt Proc 1997;29: Artemiou O, Birsn T, Tghvi S, et l. Bilterl lobr trnsplnttion with the split lung technique. J Thorc Crdiovsc Surg 1999;118: Keting DT, Mrsco SF, Negri J, et l. Long-term outcomes of cdveric lobr lung trnsplnttion: Helping to mximize resources. J Hert Lung Trnsplnt 2010;29: Roberts CM, Mcre KD, Winning AJ, Adms L, Seed WA. Reference vlues nd prediction equtions for norml lung function in non-smoking white urbn popultion. Thorx 1991;46: Ghio AJ, Crpo RO, Elliot CG. Reference equtions used to predict pulmonry function. Survey t institutions with respirtory disese trining progrms in the United Sttes nd Cnd. Chest 1990;97: Mson DP, Btizy LH, Wu J, et l. Mtching donor to recipient in lung trnsplnttion: How much does size mtter? J Thorc Crdiovsc Surg 2009;137: Oto T, Dte H, Ued K, et l. Experimentl study of oversized grfts in cnine living-donor lobr lung trnsplnttion model. J Hert Lung Trnsplnt 2001;20: Strnes VA, Brr ML, Cohen RG, et l. Living-donor lobr lung trnsplnttion experience: intermedite results. J Thorc Crdiovsc Surg 1996;112: Brr ML, Schenkel FA, Cohen RG, et l. nd donor outcomes in living relted nd unrelted lobr trnsplnttion. Trnsplnt Proc 1998;30: Bowdish ME, Pessotto R, Brbers RG, Schenkel FA, Strnes VA, Brr ML. Long term pulmonry function fter living donor lobr lung trnsplnttion in dults. Ann Thorc Surg 2005;79: Fujit T, Dte H, Ued K, et l. Experimentl study on size mtching in cnine living-donor lobr lung trnsplnt model. J Thorc Crdiovsc Surg 2002;123:104 9.