RHOBH : Kyle Richards Fears for Kim as She Has Implants Removed — 'I Lost My Mom to Breast Cancer'

Despite the highs and lows that they've weathered together, sisters Kyle and Kim Richards have an unbreakable bond.

On Wednesday evening, The Real Housewives of Beverly Hills returned after a month-long hiatus — and with the new episode came the return of former Housewife Kim, who was preparing to have both of her breast implants removed.

"It's no secret that Kim and I have a very complicated relationship. When Kim and I are bad, we are really bad," Kyle said in a confessional as flashbacks of some of the siblings' RHOBH fights played. "That's time that we can never get back."

"But when we're good, nobody can make me laugh harder than my sister Kim," said Kyle, 51.

On the week of the surgery, Kyle drove Kim to her final checkup at the plastic surgeon's office. After Kim's doctor, Dr. Handel, commented on the sisters' "resemblance," Kim shared, "My mom used to call us chocolate and vanilla."

RELATED: RHOBH's Kyle Richards Remembers Her Late Mom: 'Not a Day Goes by That I Don't Think About Her'

Jason Merritt/Getty Kyle Richards, Kim Richards

Sitting down in Dr. Handel's office, he went "over the plan for" Kim's surgery. Reviewing her history, Dr. Handel recalled that Kim "first had a breast augmentation about 30 years ago" and "had a couple of subsequent revisions" in the time since.

But most recently, she "noticed a change in the size of the breast," Dr. Handel said.

"It deflated," Kim, 55, said.

"It's like a tire on your car," Dr. Handel explained. "It just goes flat."

Looking ahead to the procedure, his "plan" was "to remove both implants" and to "do a breast uplift on both sides to make her look as normal and symmetrical as possible."

"Because you had a previous lumpectomy to remove a benign tumor, now she's left with deformity because of that," Dr. Handel told Kyle.

Describing the appearance of her breast, Kim said, "it kind of looks like somebody took a big bite out of it."

Remembering Kim's "benign tumor 10 years ago and had to have the lumpectomy," Kyle said, "It was very scary, obviously, because we lost our mom to breast cancer."

In 2002, Kim and Kyle's mom, Kathleen, died after being diagnosed with breast cancer.

"I can't even talk about it, it gives me so much anxiety," Kyle said on the episode. "Everyone always tells me, 'If you're stressed or anxious, that can create cancer.' Well great!"

After sitting down and explaining the upcoming procedure, Dr. Handel was then joined by his partner Dr. Mani to take a look at Kim's breasts in the exam room. "So here's the basic situation, she's had several pairs of implants. Obviously this side is deflated. She's got this divot here. But you have a fair amount of your own breast tissue, so I think we're going to get a very nice result without an implant because you're so petite, you don't want big breasts," he said.

Kim confirmed, "No, I never really wanted big breasts," and said that "it was my boyfriend" that talked her into getting bigger implants than she wanted.

Days later, shortly before she was wheeled into the operating room, Kim opened up about losing her mother to breast cancer.

"My mom had died of breast cancer," Kim told Dr. Mani. "And then I had the tumor a year later. It scared me. And by going through this again, what is it?"

Dr. Handel then came in and explained the plan "to remove both implants. And if there's any abnormal tissue in there, if there's anything that looks suspicious, we will remove it and send it for a biopsy."

For Kyle, the thought of the doctor's finding something while operating on her older sister was understandably concerning.

RELATED: Kim Richards to Discuss Being 'a Whipping Post as a Sister' in Tell-All Memoir, The Whole Truth

"I don't want to think about something being wrong with my sister," Kyle told cameras. "It terrifies me."

"I lost my mom to breast cancer, so when I see Kim with this doctor, it's all I can think about," said Kyle.

Kim also seemed nervous before going under the knife, telling Kyle that she hardly got any sleep because she was thinking about the surgery. "I went to bed, but I [could] barely sleep."

Finally, the time came for Kim's surgery — "explantation removal of breast implants with total capsulectomies," a member of the medical staff stated — to begin.

Getting emotional, Kim told the medical team, "I didn't get to talk to my kids this morning," as she began to cry.

While waiting for her sister to come out of surgery, Kyle also appeared nervous as memories of her late mother's time in the hospital came to mind.

"I don't like anything to do with doctors and hospitals. My whole body goes numb," said Kyle. "I go back to being in the hospital with my mom. The doctor sat us in a room and said, 'Your mom has breast cancer,' and it was stage 3 at that point."

"My mom just wanted to pretend like she was fine, because she was so scared to die," Kyle told audiences as she began to tear up. "And I can remember thinking, you know I kind of want her to be like, 'It's okay, this is life,' but she wasn't that person. She would tell me, she would say to me, 'Kyle, I don't want to die. I'm terrified and I still have so much to teach you,' " Kyle recalled, wiping away tears.

Ron Galella/ Getty Images Kyle and Kim Richards with late mother Kathleen

"She said, 'I don't want to leave, I don't want to miss out on anything with you girls,' " said Kyle.

Thankfully, Dr. Handel had only positive news for Kyle when Kim's surgery was complete.

"She's perfect," he said as he greeted Kyle in the waiting room, explaining it went "extremely well" before the RHOBH star was taken in to see her sister.

In November, Kim opened up to PEOPLE about a life-changing health scare.

“They found something,” she said at BravoCon in New York City. “Basically, I had to go in for a mammogram — women need to go for their mammograms.”

“I had a health scare with that and they had to do a biopsy,” Kim explained. “I get my last results back today and I know it’s going to be fine.”

RELATED: Kim Richards Says She’s at a ‘Peaceful Place’ in Life and Reveals Whether She’d Return to RHOBH

“It’s just a tough scare,” Kim continued. “I think that changes people. That was a hard time for me,” she said, wiping away tears.

Though the experience was horribly daunting, Kim explained that “going through something like that makes you stronger. I want to live here for a long time. I’m getting emotional, but I want to be here for me, I want to be here for my children, I want to be here for my grandkids. I want to see my kids get married.”

The Real Housewives of Beverly Hills airs Wednesdays (9 p.m. ET) on Bravo.