"At this time, we do not know the root cause or incidence rate of patient death, nor have we been able to definitively attribute the deaths to the devices or the insertion procedures for these devices", the FDA writes, adding that it is looking into two other deaths.
Since 2016 five people who have had balloons inserted into their stomachs to treat obesity have died. Intragastric balloons are created to treat obesity by taking up room in the stomach, making patients feel full.
In an August 10 letter to health care providers, the FDA says all five reports indicate that the deaths occurred within a month or less of balloon placement. Four reports involve Apollo-Endo Surgery's Orbera Intragarstric Balloon System, and one report involves ReShape Medical Inc.'s ReShape Integrated Dual Balloon System.
The ReShape balloon, approved by the FDA in June 2015, is inserted into a patient's stomach via their mouth to prevent surgical scarring. The object of the balloon is to reduce how much a person can eat by filling the stomach with the balloon, NBC News noted.
However, the agency has issued a warning to doctors treating patients with similar devices to monitor them closely.
According to Apollo Endo-Surgery, there has been one additional death of a person who received its device.
Apollo said it reported all five deaths of Orbera patients in the U.s., Mexico, Brazil and Great Britain to the FDA and has had no indication that any were related to the device or its insertion procedure.
The company has not received product-liability claims as a result of any of the deaths, it said. The FDA says it can't confirm the devices are responsible for the deaths. It states that of more than 277,000 devices distributed, there have been 21 reported deaths from January 1, 2006, through March 31, 2017.
"Patient safety is a key priority in everything we do at Apollo Endosurgery and we take adverse event reporting obligations related to our products very seriously", said Apollo Endosurgery CEO Todd Newton in a statement. ReShape is committed to supporting the continued safe and effective use of the dual balloon and is proactively communicating with physicians about this FDA update.