This example closely follows the world's first 4-way liver paired exchange that occurred in our institution in July 2022.

Deniz is a pediatric liver patient with blood type A, weighing 30kg. Her father, Ahmet, an adult with blood type O who weighs 80kg, is willing to donate a lobe of his liver to Deniz. Although Ahmet is blood type compatible with his daughter Deniz, he cannot donate either of his liver lobes because his right lobe is too large for a child, and his left lobe has an anatomically unsuitable vascular structure.

Ali is a liver patient with blood type O, weighing 75kg. His sister, Banu, also with blood type O and weighing 50kg, is willing to donate a lobe of her liver to Ali. However, even Banu's larger right lobe is too small for Ali, resulting in a size incompatibility.

Büşra is an O blood type liver patient, weighing 60kg. Her husband, Cemal, with blood type A and weighing 80kg, is willing to donate a lobe of his liver to Büşra, but they cannot proceed due to blood type incompatibility.

Can is a liver patient with blood type A, weighing 90kg. His daughter, Derin, with blood type A and weighing 60kg, is willing to donate a lobe of her liver to Can. However, even Derin's larger right lobe is too small for her father, resulting in a size incompatibility.

In summary, one of the patients faces blood type incompatibility with her co-registered donor, one patient cannot receive a donation from his co-registered donor because one of his lobes is too large, and the other is anatomically unsuitable. Two patients cannot receive donations because their co-registered donors' larger right lobes are too small. Fortunately, the liver paired exchange system comes to the rescue of these four patients. Ahmet donates a liver lobe to the adult patient Ali instead of his daughter Deniz. Banu donates a liver lobe to Büşra, who needs a smaller liver graft than her brother Ali. Cemal donates a liver lobe to Can, who shares the same blood type, rather than his blood type-incompatible wife Büşra. Derin donates her liver to the pediatric patient Deniz instead of her large-sized father Can. Thanks to this donor exchange, all four patients receive compatible liver transplants.