HEART CARE. NOW IN 3D!

Winnipeg Free Press - Section D - - GPS - BY EMILY SOHN

IN the car­diac op­er­at­ing room of the fu­ture, a sur­geon may re­pair your dam­aged heart with per­son­al­ized parts made to fit your pre­cise anatomy — by­pass­ing donor lists and im­mune-sup­press­ing drugs.

It sounds far-fetched, but in some ways, this fu­ture is al­ready here. Doc­tors use 3D-printed mod­els of or­gans and tu­mours reg­u­larly to ed­u­cate pa­tients and plan surg­eries. Some printed body parts have even made their way into hu­man bod­ies as den­tal im­plants, pros­thet­ics, skull and fa­cial re­con­struc­tions, and more. Re­searchers are also work­ing to print out cells, blood ves­sels and other liv­ing tis­sues, and ex­per­i­men­tal stud­ies have cre­ated, among other parts, knee car­ti­lage, bones and an ar­ti­fi­cial ear.

As costs de­crease and dis­cov­er­ies ac­cel­er­ate, ex­perts pre­dict 3D print­ers will be­come rou­tine tools for heart care, too. Op­ti­mistic sci­en­tists en­vi­sion cus­tom­ized patches or even full-fledged beat­ing hearts, ready to be im­planted, an ex­act fit for the pa­tient’s body.

“I re­ally think the 3D jet prin­ter is trans­for­ma­tive,” says Daniel Jones, chief of min­i­mally in­va­sive sur­gi­cal ser­vices at Har­vard Med­i­cal School in Bos­ton. “It’s go­ing to change the way doc­tors talk to pa­tients, how they plan surg­eries and how they do surg­eries. The sky is the limit in terms of ap­pli­ca­tions.”

Around since the 1980s and now avail­able in ba­sic ver­sions for just hun­dreds of dol­lars at of­fice-sup­ply stores, 3D print­ers work by cre­at­ing lay­ers of ma­te­rial in skinny slices that stack up to cre­ate a three-di­men­sional shape. The tech­nol­ogy has been used to man­u­fac­ture eye­glasses, car parts, jew­elry and more.

Med­i­cal ap­pli­ca­tions are also wide-rang­ing. All it takes is an MRI, CT scan or an­other im­age to cre­ate a three-di­men­sional blue­print for cre­at­ing ob­jects of any shape. Colours can be al­tered to make vi­su­al­iz­ing eas­ier. De­pend­ing on the de­sign and com­plex­ity of the ma­chine, ob­jects can be made with a va­ri­ety of ma­te­ri­als, in­clud­ing plas­tics, metal and rubber.

In car­di­ol­ogy, 3D mod­els are, for now, prov­ing most use­ful as ed­u­ca­tional tools. Like fin­ger­prints, a per­son’s heart is unique, and ev­ery heart prob­lem plays out in its own way, says Paul Iaizzo, as­so­ciate di­rec­tor of the In­sti­tute for En­gi­neer­ing in Medicine at the Univer­sity of Min­nesota in Min­neapo­lis. With help from de­tailed repli­cas, sur­geons can plan more ac­cu­rately and re­duce pro­ce­dure times.

In the last year, Iaizzo says, his team has printed mod­els of 17 chil­dren’s hearts with con­gen­i­tal de­for­ma­tions that re­quired sur­gi­cal re­pair. A young child’s heart can be as small as a wal­nut, so the team prints each heart four or five times larger than nor­mal. The sur­geons can then study the mod­els, show par­ents what needs to be done and dis­cuss risks. They usu­ally print out an ex­tra heart for pa­tients to take home. “One of the most crit­i­cal parts is dis­cussing the whole thing with the fam­ily,” Iaizzo says. “It’s pow­er­ful and com­fort­ing for par­ents to re­ally un­der­stand what the prob­lem is.”

The med­i­cal-de­vice in­dus­try makes fre­quent use of 3D mod­els to de­sign and test new prod­ucts, Iaizzo adds. His team has also printed hearts for med­i­cal stu­dents, sur­gi­cal res­i­dents and physicians to study and even to use in artis­tic ex­er­cises. “Tak­ing time to put a paint­brush in ev­ery crevice is re­ally valu­able,” he says. “It puts that anatomy in the brain in a three-di­men­sional way that never could have been done an­other way.”

The tech­nol­ogy of 3D print­ing is so new that rig­or­ous stud­ies have not yet as­sessed how us­ing it af­fects out­comes. But anec­do­tal ev­i­dence is pow­er­ful.

When Har­vard Med­i­cal School car­diac anes­the­si­ol­o­gist and echocar­dio­g­ra­pher Feroze Mah­mood be­gan print­ing full-size repli­cas of pa­tients’ dam­aged mi­tral valves, he gained a new ap­pre­ci­a­tion for the com­plex­ity of the struc­ture, par­tic­u­larly a Pringles potato chip-shaped re­gion called the an­nu­lus that was im­pos­si­ble to vi­su­al­ize with two-di­men­sional im­ages. In­sights gained from han­dling printed valves have helped him and col­leagues un­der­stand why a com­mon treat­ment works for some pa­tients but not oth­ers. He has now used the tech­nol­ogy hun­dreds of times.

“For most peo­ple, it is an ‘aha’ mo­ment,” says Mah­mood, who is re­search­ing the pos­si­bil­ity of print­ing pa­tient-spe­cific valve parts that would be safe to use in surg­eries. “What I fore­see is that... we will be 3D print­ing ev­ery­thing we op­er­ate on be­fore surgery. In­stru­ments, grafts and ma­te­ri­als will all be cus­tom­ized and will be printed on­site.”

Some­day, sur­geons may be able to print cus­tom­ized patches for re­pair­ing hearts dam­aged by heart at­tacks, says Adam Fein­berg, a biomed­i­cal en­gi­neer at Carnegie Mel­lon Univer­sity in Pitts­burgh. His team is work­ing both to grow heart tis­sue in Petri dishes and to use 3D print­ers to cre­ate soft, liv­ing struc­tures by em­bed­ding cells in­side gels that can be laid down in pre­cise lay­ers.

Fein­berg’s team uses con­sumer-level print­ers, which cost about US$1,000 each, far less than com­mer­cial ver­sions, priced at $100,000 or more. To en­cour­age other re­searchers to ac­cel­er­ate ad­vances, the Carnegie Mel­lon group is also us­ing open-source hard­ware and soft­ware. “The chal­lenge is to print some­thing high-qual­ity that recre­ates the func­tion of real hu­man heart mus­cle,” he says. “It’s easy to make some­thing that doesn’t work well.”

Mul­ti­ple teams of re­searchers are work­ing on this kind of bio­print­ing task, which Fein­berg says could help as many as 100,000 peo­ple a year who need heart trans­plants but face long wait­ing lists. He imag­ines 3D-printed liv­ing heart tis­sue be­com­ing avail­able in as few as 10 years, al­though he ad­mits he could be a decade off.

“It’s def­i­nitely sci­ence-fic­tion now,” he says. “But at least, we’re get­ting to the point where it’s con­ceiv­able that it could hap­pen.”

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