In May, the Regional Medical Council of the State of São Paulo (Cremesp) approved Resolution No. 400/2026, establishing guidelines for extensive, multiple, or combined elective cosmetic plastic surgeries. The resolution prohibits scheduling procedures with an estimated duration of 6 hours or longer in a single surgical session.

In 2024, Cremesp published Opinion No. 313.231/2024, warning about the risks associated with prolonged surgery and combining multiple procedures.

Angelo Vattimo, MD, a general surgeon and coloproctologist, president of the Cremesp said in a press release that “We have observed — including in ethical and professional cases reviewed by the Council — a recurring pattern of complications related to extensive surgeries and multiple procedures performed during a single surgical procedure. Among the best-known examples of combining multiple procedures is the so-called “Mommy Makeover,” a term used to describe the combination of surgeries — usually performed after pregnancy — such as abdominoplasty, liposuction, and breast surgery, all performed during the same surgical procedure. Although widely publicized on social media, the procedure requires rigorous evaluation and individualized planning, especially due to increased surgical time and physiologic trauma.

Resolution No. 400/2026 prohibits scheduling elective cosmetic plastic surgeries with an estimated duration of 6 hours or longer in a single operation, except in exceptional circumstances justified in the medical record. The resolution applies exclusively to cosmetic procedures performed within the state of São Paulo.

Surgical planning should consider the estimated duration of anesthesia, technical complexity, number of areas treated, combination of procedures, clinical condition, and concurrent use of technologies such as radiofrequency, ultrasound, plasma, and laser. The resolution also recommends performing extensive or multiple procedures in separate stages whenever possible. Hospitals and clinics must provide appropriate facilities, adequate anesthesia support, safety protocols, and an intensive care backup.

“Failure to comply with the guidelines may result in an ethical and professional investigation. It is important to emphasize that patient autonomy does not absolve the physician of technical, scientific, and ethical responsibility regarding proper surgical planning,” Vattimo added.

The association between prolonged surgery and increased complications has been documented in the medical literature for decades and has been incorporated into safety considerations in plastic surgery.

Six Hours

In a retrospective analysis of 108,303 plastic surgery procedures performed between 2012 and 2016, researchers identified prolonged operative time as an independent risk factor for surgical site infection and unplanned reoperation. In the microsurgery subgroup, which included 6148 procedures, operative time was the only independent risk factor for both outcomes (P <.001). Procedures lasting more than 10 hours had three times the risk for reoperation compared with those lasting less than 6 hours.

In a study of 15,289 plastic surgery procedures, Rambachan and colleagues found that complication rates increased progressively with a longer operative duration. The overall complication rate was 6.22% for procedures lasting less than 30 minutes and 24.86% for those lasting more than 6 hours. In multivariable analysis, every additional 30 minutes of operative time was associated with a 13% increase in the risk for overall complications.

A 2018 meta-analysis of 66 observational studies found that the risk for surgical complications approximately doubled when the operative time exceeded 2 hours. Each additional 30 minutes of surgery was associated with a 14% increase in the probability of complications.

In Brazil, a 2014 case-control study using data from services accredited by the Brazilian Society of Plastic Surgery (SBCP) identified surgery lasting longer than 4 hours and combined procedures as the main risk factors for postoperative complications. Both associations were statistically significant (P = .049).

Risk Assessment

Speaking with Medscape’s Portuguese edition, Vicente Faraon Fonseca, MD, president of the Brazilian Society of Anesthesiology, said, “There is no magical point at which surgery becomes unsafe. Risk reflects a combination of factors, including the patient’s clinical condition, procedural complexity, combination of techniques, available infrastructure, and experience of the surgical team. However, the longer the surgical and anesthetic time, the greater the exposure to complications.”

“Operating time is a relevant, objective, and easily measurable parameter; however, it should not be used in isolation. It serves as a warning sign within a multidimensional risk assessment,” said Miguel Sabino Neto, MD, PhD, plastic surgeon coordinator of the SBCP’s Scientific Committee for Guidelines and Conduct. 

Performing procedures in stages is one strategy when combining techniques increases complexity or preoperative evaluation indicates a higher risk. Carefully selected combinations can avoid additional anesthesia and reduce the total recovery time. However, excessive combinations or procedures performed without adequate assessment of cumulative risk can increase complications.

Surgical planning should also account for changes that may occur during the procedure. The surgical team should be prepared to shorten the planned procedure, stop secondary procedures, and prioritize safety.

International guidelines consider surgical duration as a component of overall risk assessment. The American Society of Plastic Surgeons, in an evidence-based safety document, adopts 6 hours as a benchmark for outpatient surgery. The International Society of Aesthetic Plastic Surgery classifies procedures lasting longer than 3 hours as having a higher risk for venous thromboembolism. According to Neto, international practice is increasingly focused on individualized risk assessment, although some jurisdictions and facilities have established operational limits for procedures performed outside hospital settings.

The SBCP has established a scientific committee to examine issues related to surgical duration and operative risks. “We are working to identify the best scientific evidence in order to develop a well-crafted scientific guideline,” Neto said.

Fonseca noted that initiatives that encourage careful surgical planning are valuable, particularly when unnecessarily prolonged procedures are discouraged.

Resolution No. 400/2026 is a regional regulation that applies exclusively to the state of São Paulo.

Following the publication of this article, Cremesp issued a statement to the newsroom on August 7, 2026. The council clarified that the primary objective of Resolution No. 400/2026 is to improve patient safety in the planning and performance of extensive, multiple, or combined elective plastic surgeries through ethical, clinical, and safety guidelines. The regulation does not address surgical duration alone but considers factors that may increase surgical, anesthetic, and perioperative risks, including combinations of procedures, prolonged surgery, cumulative surgical trauma, and concurrent use of surgical technologies.

The council also clarified that the 6-hour timeframe is a criterion for responsible planning and should not be interpreted in isolation. Medical evaluation should consider surgical complexity, number of associated procedures, clinical condition, and estimated anesthesia time. The regulation applies to preoperative planning and allows exceptions for unforeseen circumstances or complications documented in medical records.

According to Cremesp, the resolution was developed on the basis of scientific evidence and the council’s analysis of ethical and professional cases involving complications from extensive plastic surgeries and combined procedures. The council also cited an increase in complications and requests from relevant authorities as factors behind the guidelines.

The council noted that preliminary evaluations from large hospitals in São Paulo have shown positive results following implementation. Preliminary July data submitted by Vera Cruz Hospital in Campinas showed a reduction in morbidity and mortality, as well as no thromboembolic events or blood transfusions among the procedures evaluated.

Cremesp reaffirmed that Resolution No. 400/2026, rather than merely establishing a timeframe, seeks to reduce avoidable risks and ensure that every medical decision prioritizes the protection of the patient’s life, health, and safety.

Samantha Cerquetani is a Brazilian journalist specializing in health and science. She has more than a decade of experience covering health topics and editing content on medicine, nutrition, wellness, and mental health. 

This story was translated from Medscape’s Portuguese edition.