Entertainment TV 'Doubling Down with the Derricos' : Diez, 4, to Undergo Surgery, Will Have Elongated Skull Reshaped "We take the bone off and then we reshape his skull back into a more rounded shape," a doctor tells Karen and Deon Derrico about their 4-year-old son's upcoming procedure By Natalie Stone Published on July 12, 2021 09:30 AM Share Tweet Pin Email Karen and Deon Derrico are mentally preparing to face one of the most terrifying moments of their lives. On Tuesday's Doubling Down with the Derricos, the Las Vegas-based couple speaks with a doctor about the logistics of their 4-year-old son Diez's upcoming surgery — a procedure he will undergo in order to have his elongated skull reshaped. In a PEOPLE exclusive sneak peek at the episode, the doctor demonstrates with a model skull what will be done to Diez's head during the operation, which is anticipated to take four to six hours. "We basically start by making an incision across the top," the doctor tells the parents of 14 on a video call, explaining that it "goes from one side to the other." "And then we take the skin and we peel the front part forward this way and then we take the back part and we peel it back that way," he continues. "And so then the top of his head is exposed." Touching the top part of the skull, the doctor says "this part of the skull will come off." TLC Doubling Down with the Derricos: Deon and Karen Are 'Angry' Diez's Head Shape 'Was Overlooked' From there, the team of doctors will "take that skull, we cut it into pieces," he explains as a mosaic of images appear on the screen, showcasing where the medical staff will "make the cuts." TLC "And then we take the bone off and then we reshape his skull back into a more rounded shape," the doctor states before showing what the skull will look like after the procedure. "We make it less long, and we make it wider on the sides and his skull will be like a normal-looking skull." Hearing and watching the demonstration of what will happen to their young son in the operating room brings tears to both Karen and Deon's eyes. TLC Once Diez is in recovery, his parents will be there to comfort him in the hospital room. "Our goal is that the last thing he sees is mom as he's going to sleep and the first thing he remembers while he's waking up is mom while he's waking up," the doctor says. Doubling Down with the Derricos: Diez, 4, Undergoing Surgery on His Head 'Could Be Life-Altering' Although the seriousness of Diez's surgery is difficult to hear, Karen, 41, is counting her many "blessings." "It's like, I'm fighting in my mind, like, 'This is so hard to hear, count your blessings,'" she says in a confessional about her mindset. "'This is so hard to hear, but count this blessing.'" Karen and Deon Derrico with son Diez. TLC Speaking to the doctor, Deon, 50, says that his tears "come from hating this" for Diez. On a previous episode, Deon explained to his mother that Diez's head was far below the average size. "The average head should be 80 cm. They don't even want it to be 70 — that's considered low. His is 65," Deon said. "The skull fused too fast and if it fused too fast, that means it's just growing the length, but it's not growing the normal width." Doubling Down with the Derricos airs Tuesdays (10 p.m. ET) on TLC.