Layer by layer: how 3D printing is transforming hospitals and medical research

Prac­tising an oper­a­tion before sur­gery, edu­cat­ing patients, adapt­ing equip­ment to a dis­ab­il­ity, repair­ing obsol­ete tech­no­logy… 3D print­ing has made its way into hos­pit­als, bene­fit­ing patients, health­care pro­fes­sion­als and research­ers alike, prom­ising more per­son­al­ised care and sus­tain­able techniques.

Since Feb­ru­ary 2023, Brest Hos­pit­al has developed its own 3D print­ing plat­form, W.Print, join­ing hos­pit­als in Lyon, Bes­ançon and Par­is. This new ser­vice builds on a research pro­ject ori­gin­ally led by Samuel Guigo on the man­age­ment of com­plex intra­cra­ni­al aneurysms. “These oper­a­tions require sig­ni­fic­ant pre­par­a­tion before­hand. I there­fore developed patient-spe­cif­ic 3D ana­tom­ic­al mod­els, enabling sur­geons to rehearse the oper­a­tion, anti­cip­ate dif­fi­culties and adapt sur­gic­al tech­niques,” explains the researcher.

These mod­els also help pre­pare sur­gic­al strategies. For example, in the case of a large tumour loc­ated beneath the eye – in the max­il­lary sinus – 3D print­ing makes it pos­sible to plan the bone recon­struc­tion required after remov­al, well in advance of the oper­a­tion. More gen­er­ally, health­care pro­fes­sion­als can thus prac­tise on real­ist­ic ana­tom­ic­al mod­els, some­times with the addi­tion of cir­cuits sim­u­lat­ing blood flow, or flex­ible or rigid mater­i­als to rep­lic­ate the human body as closely as possible.

Cur­rently the platform’s coordin­at­or, Samuel Guigo over­sees and sup­ports nearly 80 pro­jects a year. At this stage, we are not talk­ing about bioprint­ing (where bio­lo­gic­al mater­i­als are gen­er­ated for grafts, for example), or med­ic­al devices (which may be in pro­longed con­tact with the body). We are simply talk­ing about fil­a­ment or res­in print­ers that can cre­ate all sorts of objects. So why all the hype?

In addi­tion to med­ic­al applic­a­tions, the Brest-based plat­form has diver­si­fied to cov­er every aspect of hos­pit­al life, start­ing with patients and their fam­il­ies. When it comes to explain­ing a con­di­tion, a deform­ity or a sur­gic­al pro­ced­ure, noth­ing beats a phys­ic­al object. In cases of mul­tiple dis­ab­il­it­ies in chil­dren, for example, these mod­els become thera­peut­ic edu­ca­tion tools, help­ing fam­il­ies to bet­ter under­stand and engage with the care path­way. The plat­form is also part of the Rehab Lab net­work, ded­ic­ated to cre­at­ing per­son­al­ised assist­ive devices with and for people with dis­ab­il­it­ies. The aim: more sus­tain­able, less expens­ive and bet­ter-util­ised bespoke solu­tions, thereby facil­it­at­ing a return home after hospitalisation.

3D print­ing helps tackle the prob­lem of obsol­ete hos­pit­al equip­ment, with an estim­ated sav­ing of between 120,000 and 140,000 euros per year

“But the major­ity of pro­jects actu­ally focus on the prac­tic­al, day-to-day needs of the hos­pit­al,” reveals the coordin­at­or. Pipette hold­ers, adap­ted stands, spare parts unavail­able on the mar­ket: 3D print­ing helps tackle the prob­lem of obsol­ete hos­pit­al equip­ment. This res­ults in estim­ated sav­ings of between €120,000 and €140,000 per year, at a time when pub­lic hos­pit­als are under sig­ni­fic­ant budget­ary pressure.

This approach is also driv­ing a shift in work­ing prac­tices. Care assist­ants, stretch­er bear­ers, cater­ing staff and admin­is­trat­ive per­son­nel now come for­ward with their spe­cif­ic needs to co-design solu­tions. For Samuel Guigo, this is a way of redu­cing the “irrit­ants” of daily life, those minor issues that under­mine the work­ing atmo­sphere, and of fos­ter­ing a cul­ture of innov­a­tion among all staff. Today, requests from oth­er hos­pit­als are flood­ing in, and Samuel Guigo, who is cur­rently the only per­son man­aging the entire ini­ti­at­ive, is shar­ing his expert­ise with oth­er insti­tu­tions whilst train­ing stu­dents in 3D design.

In Nantes, an ongo­ing mul­tidiscip­lin­ary research pro­ject provides a con­crete illus­tra­tion of the poten­tial and chal­lenges of 3D print­ing in health­care. Bring­ing togeth­er Nantes Uni­ver­sity Hos­pit­al, the Oniris VetAgro­Bio Veter­in­ary School and Inserm’s RMeS labor­at­ory, the GI Jaw pro­gramme has been focus­ing on the treat­ment of cleft lips and pal­ates since 2021.

Today, these con­gen­it­al mal­form­a­tions, char­ac­ter­ised by a par­tial or com­plete absence of bone between the mouth and the nose, are mainly treated using bone grafts taken from the child’s hip. This is an effect­ive solu­tion, but one that nev­er­the­less involves post-oper­at­ive pain and an addi­tion­al scar for young patients who under­go sur­gery as early as five or six years of age. “We need 2 or 3 ml of bone, so some­times we have to sup­ple­ment it with bone sub­sti­tute,” adds Pierre Corre, pro­fess­or of max­il­lo­fa­cial sur­gery at Nantes Uni­ver­sity Hos­pit­al and one of the three pro­ject lead­ers. “That’s where the clinician’s chal­lenge becomes the researcher’s!” says Bap­tiste Char­bon­ni­er, a research engin­eer at Inserm ¹, the second mem­ber of the trio.

The idea behind the pro­ject is simple: to replace the miss­ing bone without tak­ing it from else­where, using a 3D-prin­ted bio­ma­ter­i­al per­fectly adap­ted to each patient’s ana­tomy. Why not use ceram­ic or the stand­ard bone cement used in dent­al pro­ced­ures? “Because this mal­form­a­tion of the upper jaw is loc­ated in a com­plex area, at risk of infec­tion between the mouth and the nose: the aim is to cre­ate per­fect con­tact so that the blood ves­sels of the nat­ive bone can rap­idly col­on­ise the implant and enable deep bone regrowth,” explains Pierre Corre. A new mater­i­al there­fore needs to be developed that is mal­le­able dur­ing implant­a­tion, hardens once in place and is even­tu­ally resorbed to make way for new bone.

The aim is to cre­ate per­fect con­tact so that the blood ves­sels from the nat­ive bone can rap­idly col­on­ise the [3D-prin­ted] implant and enable deep bone regrowth

For this study (and to com­plete the trio), Pierre Maitre, a veter­in­ari­an and seni­or lec­turer in sur­gery at the Oniris Veter­in­ary School, has ini­ti­ated a recruit­ment drive for dogs with cleft lip and pal­ate, which are usu­ally euth­an­ised at birth due to this mal­form­a­tion, to devel­op a new sur­gic­al recon­struc­tion tech­nique using 3D print­ing. For this study – and to com­plete the trio – Pierre Maitre, a vet and seni­or lec­turer in sur­gery at the Oniris Veter­in­ary School, has organ­ised a recruit­ment drive for dogs with cleft lip and pal­ate, which are usu­ally euth­an­ised at birth due to this mal­form­a­tion, to devel­op a new sur­gic­al recon­struc­tion tech­nique using 3D printing.

It all begins with a CT scan: the implant is digit­ally designed to pre­cisely match the bone defect and the sur­round­ing mucosa, and to facil­it­ate inser­tion dur­ing sur­gery. “After print­ing, the cemen­ted implant dries and is then ster­il­ised,” explains Bap­tiste Char­bon­ni­er. To make it mal­le­able, the bio­ma­ter­i­al is rehyd­rated in the oper­at­ing theatre. This hydra­tion also allows it to be impreg­nated with the patient’s bone mar­row, which will become the new col­on­ising cells, and trig­gers the set­ting of the cement, which will allow the implant to harden after inser­tion. Once in place, the 3D implant then becomes a tem­por­ary scaf­fold, gradu­ally col­on­ised by the patient’s bone cells.

The res­ults are prom­ising – after six months, the implant is almost entirely resorbed, replaced by nat­ur­al bone. Tri­als have already been con­duc­ted on 18 dogs, which could become ambas­sad­ors for this new tech­nique among future young patients. But the research­ers remain real­ist­ic: “We still have a high­er fail­ure rate than with auto­grafts, but we have observed that bone regen­er­a­tion appears to be great­er with this new mater­i­al, so that is already progress!”

The pro­ject, fun­ded by the ANR for a fur­ther four years, is now enter­ing a phase of mater­i­al refine­ment and reg­u­lat­ory approv­al, with the aim of becom­ing a (bio­de­grad­able) Class 3 med­ic­al device. Every year in France, around 1 in 700 chil­dren is born with a cleft lip and pal­ate, the major­ity of whom have a bone defect. Whilst the tech­nique is not yet ready for routine clin­ic­al use, it already points the way towards more per­son­al­ised, less invas­ive and less pain­ful treat­ment for the young patients of tomorrow.

Sophie Podevin