The two most common obesity surgeries, gastric bypass and gastric sleeve, have few short-term complications and show no significant differences, according to study findings published in the journal JAMA Network Open. These are the first results of a multicentre randomised controlled trial comparing obesity surgeries conducted by the University of Gothenburg.
Patients undergoing obesity surgery will normally have a BMI of at least 40, or 35 if they also have other serious medical conditions related to obesity.
The most common procedures are gastric bypass, where a large part of the stomach and part of the small intestine are bypassed, and gastric sleeve, where a large part of the stomach is surgically removed.
The aim of the current study was to compare the short-term risks of the different procedures.
The study is the largest of its kind. 1735 adult patients planned for surgery in Norway and Sweden between 2015 and 2022 agreed to participate, and they were randomly assigned to either gastric bypass or gastric sleeve.
Relatively few complications
Surgical time was longer for gastric bypass, averaging 68 minutes compared to 47 minutes for gastric sleeve, but hospitalisation after surgery was one day regardless of method.
The follow-ups also gave equivalent results for the two methods.
At 30 days after surgery, both groups had relatively few complications such as haemorrhage, leakage, blood clots and infections.
No deaths occurred during the follow-up period of a total of 90 days.
“For both surgical procedures, the risk of complications is very low, especially from an international perspective, and there is no statistically significant or clinically relevant difference between the groups,” says Suzanne Hedberg, first author of the study.
Many stakeholders and many opinions
“Many people have had surgery, or are on waiting lists for surgery, and there are lots of discussions and opinions about the different methods. What the study shows is that patients and doctors can now choose their surgical method without considering short-term surgical risks,” she says.
Suzanne Hedberg defended her thesis in surgery at Sahlgrenska Academy, University of Gothenburg in April 2023, and is a consultant at Sahlgrenska University Hospital.
The study, included in her thesis, is the first publication with results from BEST (Bypass Equipoise Sleeve Trial), a Scandinavian registry-based randomised controlled multicentre study comparing the two methods of obesity surgery.
The main outcome of the trial which analyses the risk of complications and weight progression over 5 years, is expected to be completed in 2028.
“For the ongoing studies, we are off to a good start with equivalent groups, laying a good foundation for further comparisons of more long-term results,” concludes Suzanne Hedberg.
Including patients as partners for making decisions about their medical treatments is an important aspect of patient-centred care. A new study from England examined choices that patients with breast cancer make when considering where to have surgery for their condition and assessed how policies that offer such choices might affect inequalities in the health care system. The findings are published in CANCER.
For the study, investigators analysed data from the National Health Service (NHS), the publicly funded health care system in the United Kingdom that offers patients with cancer the opportunity to select any hospital providing cancer treatment, and identified all women diagnosed with breast cancer from 2016 to 2018 who had breast-conserving surgery or a mastectomy.
Records showed that 22 622 of 69,153 patients undergoing breast-conserving surgery (32.7%) and 7179 of 23 536 patients undergoing mastectomy (30.5%) bypassed their nearest hospital to receive surgery farther away from home. Women who were younger, without additional medical conditions, of white ethnic background, or lived in rural areas were more likely to travel to more distant hospitals.
Patients were more likely to be treated at hospitals classified as specialist breast reconstruction centres even if they personally were not undergoing breast reconstruction after surgery. Patients who had a mastectomy and immediate breast reconstruction were more likely to travel to hospitals that had surgeons with a strong media reputation for breast cancer surgery, and patients were less likely to travel to hospitals with shorter surgical waiting times. Patients did not seem to make choices based on hospitals’ research activity, quality rating, breast re-operation rates (to remove additional cancer cells that were missed), or status as a multidisciplinary cancer centre (where patients can receive all their care at one location).
The investigators noted that this separation – elderly patients, those with comorbidities, and those from ethnic minority backgrounds receiving care at their local hospital, while others travel to other hospitals and specialist centres – could further drive inequalities in access to quality care.
“As marginalized groups already face barriers to high-quality care, it is important for policy makers to consider measures that mitigate against the risks of increasing inequalities in access and outcomes, by for example providing free transport, accommodation, or even protection against loss of income,” said co-author Lu Han, PhD, of the London School of Hygiene & Tropical Medicine. “Moreover, patients prefer to access information on the quality of breast cancer care of the hospitals in their region at the start of the management pathway when a diagnosis is sought. Such information should be easy to understand and presented in a format that can support the trade-offs that patients have to make.”
Young people who have had surgery for obesity do not improve their mental health despite significant and permanent weight loss. At the same time, bariatric surgery also increases the risk of early alcohol problems. This is according to the largest long-term study of young people who have undergone bariatric surgery, the results of which were published in Lancet Child and Adolescent Health.
The researchers studied mental health problems – before and after surgery – among all young people in Sweden who underwent bariatric surgery between 2007 and 2017. The study was conducted using register data, which enabled the scope of the study and facilitated comparisons with other groups in society.
The study recruited 1554 adolescents (< 21 years) with severe obesity underwent bariatric surgery between 2007 and 2017, 1169 (75%) of whom were female. At time of surgery, the mean age was 19·0 years [SD 1·0], and the mean BMI was 43·7 kg/m2 (SD 5·5). They were matched with 15 540 adolescents from the general population.
It was found that young people who underwent surgery were more likely to have received treatment and medication for mental health problems already five years before the surgery.
“Although mental illness generally increases between the ages of 15 and 21, for this group the need for treatment increased faster than for young people in general”, says Kajsa Järvholm, Associate Professor of Psychology at Lund University.
Unfortunately, this pattern continued even after obesity surgery; the young people who had the surgery continued to have a greater need for mental health treatment than their peers.
“Obesity surgery has very positive effects on weight, blood sugar and blood pressure control, but when it comes to mental health, it does not get better or worse after bariatric surgery”, says Martin Neovius, Professor of Clinical Epidemiology at Karolinska Institutet.
Additional findings from the new study include an increase in dependency diagnoses, particularly on alcohol, in the surgical group, both in comparison to pre-surgery and to young people in general.
The study is the largest long-term study in the world of young people who have had obesity surgery.
Already long surgical waiting lists in the Northern Cape appear to have ballooned in recent months. In May, the province’s MEC for Health Maruping Lekwene told the province’s legislature that surgical waiting lists in the province stood at just under 4000. According to more recent figures from the Northern Cape Department of Health’s 2023/24 First Quarterly report, the surgical backlog stands at 6373 – an increase of more than 50% on the figure given in May.
Lulu Mxekezo, Northern Cape Department of Health Spokesperson, confirmed to Spotlight last week that the surgical backlogs had indeed increased from around 4000 to around 6000. She said that the numbers fluctuate as the need continues to increase on a daily basis.
“The shortage of specialised theatre staff makes it impossible for us to utilise all theatres daily to perform the procedures,” said Mxekezo, adding that the department will not compromise the safety and lives of patients and operate in theatres with no specialised theatre staff.
The increase in the backlog came despite the outsourcing of some surgical services in the province. Lekwene told the legislature that the Northern Cape Department of Health pays Gauteng-based Medicomed (captured as Medicore-Mets in the legislature minutes) R400 000 per month to assist with orthopaedic surgeries at Robert Mangaliso Sobukwe (RMS) Hospital in Kimberly on a month-to-month basis. He said the company supplies the department with specialised theatre nurses which is a scarce skill in the province. In May, Lekwene told legislators that the company had assisted with 57 surgeries over a two-week period.
Lack of theatre staff
The quarterly report stated that the backlog is fuelled by the lack of theatre staff at RMS hospital, and that the private sector was called in to fill this gap.
When asked by Izak Fritz, Democratic Alliance member of the Provincial Legislature, why the department does not appoint specialist nurses instead of outsourcing these services, Lekwene answered that there are unfortunately not enough theatre specialist nurses in the province.
“For us to take this route, it means that we need to have internal capacity. For instance we will have a neurosurgeon but we will not have an anaesthetist. We have nurses, but we do not have theatre specialist nurses,” he said.
He said they do not enjoy outsourcing, but that because of the urgency and the growing backlog the department has to act swiftly. “However as soon as the backlog has been reduced, we will then try to use our internal staff,” he said.
Lekwene also told the legislature that the backlog was mostly caused by the Covid-19 pandemic. “Remember that for two years during Covid-19, hospitals were closed,” he said.
Left stranded
Some workers at RMS said the long waiting list has left many patients frustrated and stranded. One doctor described the situation to Spotlight as “dire”. “The hospital has four fully equipped theatres but patients do not get help,” he said. He asked not to be named for fear of losing his job.
“Yes, we do have a shortage of nurses, but it is not as bad as they say. We are available as doctors, but without the help from nurses we are unable to perform surgeries at all,” he said.
The doctor said that currently the list of patients that need to receive emergency surgery is longer than 30. He said that for ordinary surgeries such as hip replacements there are patients who have been in hospital for more than 18 months, while some have been waiting for cataract surgery for five years.
A strain on staff and patients
Dennis Segano, provincial chairperson of Health and Other Services Personnel Trade Union in South Africa (HOSPERSA) said the surgery backlog is putting a strain on both nurses and patients.
He said the main problems that they see at RMS is the shortage of specialised theatre nurses and a lack of equipment. “When you enter the theatres there are enough doctors but not enough nurses,” he said. “We have a problem with our theatre nurses who are often outsourced by the service provider to work during their surgery marathons at the RMS hospital but have to wait three months or sometimes even six months before they can get paid.”
Spotlight asked Mxekezo about the late payment allegations but had not received a response by the time of publication.
“We don’t know why the government is not appointing the nurses instead of paying a service provider,” Segano said. “The system is burdened, the nurses in orthopaedic wards are burdened and we feel sad for the patients who have to spend months in hospital. “As a patient when you have a fracture, you must be able to go to theatre immediately, but in this province, you have to wait months before you receive help.”
“Stakeholders are also assisting us in performing theatre marathons to deal with the backlog,” Mxekezo said.
For example, in October last year, disaster relief organisation Gift of the Givers sent a team of theatre nurses and anaesthetists to assist with the backlog at RMS. According to Ali Sablay, the organisations project manager, they performed 72 operations on 72 patients during the catch-up drive.
Long-term solution
When asked what the department’s long-term plans are to reduce the pressure, Mxekezo explained that the operationalisation of theatres in district hospitals with specialised theatre staff will assist in minimising the backlog at RMS as many patients are transferred from districts.
Segano agreed that a long-term solution is to equip district hospitals with decent theatres and specialised theatre nurses.
“Minor fractures must be dealt with at district hospitals. RMS Hospital must only perform serious surgeries,” he said. “If the department can prioritise Harry Surtie Hospital and De Aar Hospital with theatre staff and equipment, RMS Hospital will operate much better and the patients will be helped. It is incorrect to send all patients of the Northern Cape to one hospital in Kimberly. They will not succeed.”
“Permanent employment of theatre staff will also assist in stabilising the surgical backlogs,” Mxekezo said.
Sceptical opposition
Fritz told Spotlight the DA is very concerned about the growing backlog in the Northern Cape and that they have repeatedly highlighted surgery backlogs at the provinces only tertiary facility (RMS).
“When one looks at nursing appointments at the RMS hospital, we see a trend whereby more nurses’ contracts are terminated each year than the amount of nurses who actually get appointed,” he said. “In effect, the hospital only operationalises four of its nine theatres.”
“Despite agreements with private agencies for surgery marathons to help tackle the backlogs, this only has a limited impact because of the inability to operationalise more theatres and to ensure there is an availability of more beds for recovery,” he said.
Fritz said the reality is that the people who require elective surgery often have to wait years to be attended to while their condition progresses. “Only when their case becomes an emergency can they be bumped up the list, and by that time their disease has become worse and their hopes of a full recovery is minimised,” he said.
Wynand Boshoff, the Freedom Front Plus’s (FF+) Northern Cape Provincial Leader, said in an interview with Spotlight last week that the problem with the department is that it is an entity that is riddled with mismanagement and a culture which aims for anything but service delivery.
He said the FF+ is not only approached by patients, but also by doctors on a regular basis who want to leave the health department because of management that he said has completely abandoned services.
“It is clear that more is needed than the appointment of a new minister or a new Head of Department, as the legacy of mismanagement overwhelms individual role players. A comprehensive investigation and steadfast disciplinary action is needed,” he said. “Repeat offenders should not be tolerated in the department, not even in the most humble of positions.”
As Spotlight previously reported, the Northern Cape Department of Health has had several acting heads in the last three years and several senior officials have and are facing charges in court. The current Head of Department is Dr Alastair Kantani, who has been acting in the position since 8 September following the arrests of seven officials, including former head Dr Dion Theys who now occupies the post of Medical Director in the department. In a statement issued by the department on 13 September Lekwene said this action is informed by the constitutional responsibility to ensure relative stability in the delivery of healthcare services in the province.
Patients taking Glucagon-like peptide-1 (GLP-1) receptor agonists should stop taking them before they have surgery, due to the risk of aspirating while under general anaesthesia. This is the latest advice from the American Society of Anesthesiologists (ASA).
Initially approved by the Food and Drug Administration (FDA) for type 2 diabetes mellitus and cardiovascular risk reduction, GLP-1 agonists have shot up in popularity due to their effectiveness in weight loss. Despite having recent FDA approval, they have been used off-label for this purpose for quite some time.
When it comes to surgery, a number of organisations have recommended to hold these drugs either the day before or day of the procedure. For patients on weekly dosing, it is recommended to hold the dose for a week, the ASA notes.
GLP-1 agonists are associated with adverse gastrointestinal effects such as nausea, vomiting and delayed gastric emptying. The effects on gastric emptying are reported to be reduced with long-term use, most likely through rapid tachyphylaxis at the level of vagal nerve activation. Based on recent anecdotal reports, there are concerns that delayed gastric emptying from GLP-1 agonists can increase the risk of regurgitation and pulmonary aspiration of gastric contents during general anaesthesia and deep sedation. Patient taking GLP-1 agonists are more likely to have increased residual gastric contents as predicted by adverse gastrointestinal symptoms (nausea, vomiting, dyspepsia, abdominal distension).
The use of GLP-1 agonists in paediatrics has primarily been reported for the management of type 2 diabetes mellitus and obesity. The published literature on GLP-1 agonists in paediatrics is predominantly from paediatric patients 10 to 18 years old and concerns are similar to those reported in adults. During the conduct of general anaesthesia/deep sedation, children on GLP-1 agonists have similar gastrointestinal adverse events at a rate similar to adults.
In a review of the literature, the ASA Task Force on Preoperative Fasting found that, beyond a few case reports, there was little evidence for guidance on preoperative management of GLP-1 agonists. Nevertheless, they made recommendations for elective procedures. In the case of urgent or emergent procedures, they suggested treating the patient as ‘full stomach’.
If the patient’s GLP-1 agonists prescribed for diabetes management are held for longer than the dosing schedule, the guidelines urge surgeons to consider consulting an endocrinologist for bridging the antidiabetic therapy in order to avoid hyperglycaemia.
They further recommend that if gastrointestinal symptoms, such as severe nausea/vomiting/retching, abdominal bloating, or abdominal pain, are present, surgeons should consider delaying elective procedures. If the patient has no gastrointestinal symptoms and the GLP-1 agonists have been held as advised, the surgical team can carry on as normal.
In a new research perspective published in Oncoscience, researchers from Germany discuss the diagnosis and management of postoperative wound infections in the head and neck area. Key topics include patient risk factors, the importance of sterilisation, and the most common complications.
In everyday clinical practice at a department for oral and maxillofacial surgery, a large number of surgical procedures in the head and neck region take place under both outpatient and inpatient conditions. The basis of every surgical intervention is the patient’s consent to the respective procedure. Particular attention is drawn to the general and operation-specific risks.
Particularly in the case of soft tissue procedures in the facial region, bleeding, secondary bleeding, scarring and infection of the surgical area are among the most common complications/risks, depending on the respective procedure. In their new perspective, researchers Filip Barbarewicz, Kai-Olaf Henkel and Florian Dudde from Army Hospital Hamburg in Germany discuss the diagnosis and management of postoperative infections in the head and neck region.
“In order to minimise the wound infections/surgical site infections, aseptic operating conditions with maximum sterility are required.”
Furthermore, depending on the extent of the surgical procedure and the patient‘s previous illnesses, peri- and/or postoperative antibiotics should be considered in order to avoid postoperative surgical site infection. Abscesses, cellulitis, phlegmone and (depending on the location of the procedure) empyema are among the most common postoperative infections in the respective surgical area. The main pathogens of these infections are staphylococci, although mixed (germ) patterns are also possible.
“Risk factors for the development of a postoperative surgical site infection include, in particular, increased age, smoking, multiple comorbidities and/or systemic diseases (eg, diabetes mellitus type II) as well as congenital and/ or acquired immune deficiency.”
Concerns that surgery patients would have a more difficult recovery if their doctors had to abide by a five-day limit on opioid pain medication prescriptions did not play out as expected, finds a study published in JAMA Health Forum.
Instead, the University of Michigan-led researchers found that , after the largest insurer in that US state put the limit in place, patient-reported pain levels and satisfaction didn’t change at all for adults who had their appendix or gallbladder removed, a hernia repaired, a hysterectomy or other common operations.
At the same time, the amount of opioid pain medication patients covered by that insurer received dropped immediately after the limit went into effect. On average, patients having these operations received about three fewer opioid-containing pills.
The study, which merges two statewide databases on patients covered by Blue Cross Blue Shield of Michigan, is the first large study to evaluate whether opioid prescribing limits change patient experience after surgery.
Measuring the impact of limits from patients’ perspectives
The BCBSM limit of five days’ supply, which went into effect in early 2018, is even stricter than the seven-days’ supply limit put in place a few months later by the state of Michigan.
Other major insurers and states have also implemented limits, most of which allow are seven-day limits.
Limits are designed to reduce the risk of long-term opioid use and opioid use disorder, as well as to reduce the risk of accidental overdose and the risk of unauthorized use of leftover pills.
“Opioid prescribing limits are now everywhere, so understanding their effects is crucial,” said lead author Kao-Ping Chua, MD, PhD.
“We know these limits can reduce opioid prescribing, but it hasn’t been clear until now whether they can do so without worsening patient experience.”
He noted that even the 15% of patients who had been taking opioids for other reasons before having their operations showed neither an increase in pain nor a decrease in satisfaction after the limit was put in place, even though opioid prescribing for these patients decreased.
That decrease was actually contrary to the intent of the limit, which was only designed to reduce prescribing to patients who hadn’t taken opioids recently.
How the study was done
For the new study, Chua and colleagues used data from the Michigan Surgical Quality Collaborative, which collects data on patients having common operations at 70 Michigan hospitals. The MSQC surveys patients about their pain, level of satisfaction and level of regret after their operations.
In all, they were able to look at opioid prescribing and patient experience data from 1,323 BCBSM patients who had common operations in the 13 months before the five-day limit went into effect, and 4,722 patients who had operations in the 20 months after the limit went into effect.
About 86% of both groups were non-Hispanic white, patients’ average age was just under 49, and just under a quarter of both groups had their operations on an emergency or urgent basis. Just under half were admitted to the hospital for at least one night.
About 27% of both groups had their gallbladders taken out laparoscopically, and a similar percentage had minor hernia repairs.
About 10% had an appendectomy done laparoscopically, and a similar percentage had laparoscopic hysterectomies.
The rest had more invasive procedures, like open hysterectomies major hernia repairs, or colon removal.
The percentage of prescribers who prescribed opioids to their patients having these operations did not change, but the percentage of patients who filled a prescription for an opioid did, possibly because pharmacists rejected prescriptions that weren’t compliant with the BCBSM limit, Chua speculates.
Jennifer Waljee, MD, MPH, MS, senior author of the study, notes that the MSQC database doesn’t include all types of procedures, such as knee replacements and spine surgery, which typically require larger postoperative opioid prescriptions because of their associated pain.
She indicated that it’s important to understand the impact of opioid prescribing limits on the experiences of such patients, because limits have the most potential to worsen pain for these individuals.
“Opioid prescribing limits may not worsen patient experience for common, less-invasive procedures like those we studied, because opioid prescriptions for most of these procedures were already under the maximum allowed by limits.
“But this may not be the case for painful operations where opioid prescribing was suddenly cut from an 8- to 10-day supply to a 5-day supply,” said Waljee.
She added, “The message of this study is not that we can simply go to five days’ supply across the board for operations.
“We need to understand the effects of these limits across a broad range of procedures and patients given how much pain needs vary in order to right size prescribing to patient need without resulting in additional harms.”
According to a new international study published in the New England Journal of Medicine, cleft palate surgery at the age of six months provides better conditions for speech and language development compared to surgery at 12 months.
Isolated cleft palate is a congenital condition where the palate is not closed and there is an opening between the mouth and the nose. The condition occurs in 1 to 25 per 10 000 births worldwide.
“There has previously been limited evidence for the optimal age for cleft palate surgery in children to achieve the best results”, says Anette Lohmander, professor emeritus at at Karolinska Institutet and principal investigator for the Stockholm centre in the study.
The study, by researchers from Karolinska Institutet and Karolinska University Hospital, among others, involved 558 children from 23 different centres around Europe and South America. Of these, 235 children were randomly assigned to a group to undergo surgery at six months of age and 226 children were randomly assigned to undergo surgery at twelve months of age.
Speech-language therapists/pathologists performed standardised audio-video recordings at one, three and five years of age. The researchers then evaluated the children’s babbling, velopharyngeal function, and speech.
At age five, the researchers found insufficient velopharyngeal function in 21 children (8.9%) who had surgery at six months of age compared with 34 children (15%) who had surgery at age 12 months.
Complications resulting from surgery were rare in both groups. Four serious adverse events were reported but were resolved on follow-up.
The conclusion of the study was that velopharyngeal function for speech at five years was better in the children who had undergone surgery at six months of age than in those who had undergone surgery at 12 months of age. Risks associated with earlier repair may include maxillary arch constriction and the need for secondary surgery for velopharyngeal insufficiency.
“An additional advantage of the early surgery age was a higher incidence of canonical syllables. It is a milestone in children’s language development and is established in typically developed children by the age of ten months at the latest,” says Anette Lohmander, who continues. “The children included in the study had no developmental delay or other deviant conditions. The conclusion is that when it is possible to operate on the cleft palate early, it seems to provide the best conditions for speech and language development.”
Microplastics seem ubiquitous in today’s environment, being found everywhere from rivers to inside the stomach. Now, in a pilot study of patients who underwent heart surgery, researchers in ACS’ Environmental Science & Technology report that they have found microplastics in many heart tissues. They also report evidence suggesting that microplastics were unexpectedly introduced during the procedures.
Microplastics are plastic fragments less than 5mm wide, or about the size of a pencil eraser. Research has shown that they can enter the human body through the mouth, nose and other body cavities with connections to the outside world. Yet many organs and tissues are fully enclosed inside a person’s body, and scientists lack information on their potential exposure to, and effects from, microplastics. So, Kun Hua, Xiubin Yang and colleagues wanted to investigate whether these particles have entered people’s cardiovascular systems through indirect and direct exposures.
In a pilot experiment, the researchers collected heart tissue samples from 15 people during cardiac surgeries, as well as pre- and post-operation blood specimens from half of the participants. Then the team analysed the samples with laser direct infrared imaging and identified 20 to 500 micrometre-wide particles made from eight types of plastic, including polyethylene terephthalate, polyvinyl chloride and poly(methyl methacrylate). This technique detected tens to thousands of individual microplastic pieces in most tissue samples, though the amounts and materials varied between participants. The blood samples also all contained plastic particles, but after surgery their average size decreased, and the particles came from a wider range of plastics.
Although the study had a small number of participants, the researchers say they have provided preliminary evidence that various microplastics can accumulate and persist in the heart and its innermost tissues. They add that the findings show how invasive medical procedures are an overlooked route of microplastics exposure, providing direct access to the bloodstream and internal tissues. More studies are needed to fully understand the effects of microplastics on a person’s cardiovascular system and their prognosis after heart surgery, the researchers conclude.
The thymus gland, which produces immune T cells before birth and during childhood, is often regarded as non-functional in adults, and is sometimes removed during cardiac surgery for easier access to the heart and major blood vessels. New research led by investigators at Massachusetts General Hospital (MGH) and published in the New England Journal of Medicine has uncovered evidence that the thymus is in fact critical for adult health generally and for preventing cancer and perhaps autoimmune disease.
To determine whether the thymus provides health benefits to adults, the team evaluated the risk of death, cancer, and autoimmune disease among 1146 adults who had thymectomy during surgery and among 1146 demographically matched patients who underwent similar cardiothoracic surgery without thymectomy. The scientists also measured T cell production and blood levels of immune-related molecules in a subgroup of patients.
Five years after surgery, 8.1% of patients who had a thymectomy died compared with 2.8% of those who did not have their thymus removed, equating to a 2.9-times higher risk of death. Also during that time, 7.4% of patients in the thymectomy group developed cancer compared with 3.7% of patients in the control group, for a 2.0-times higher risk.
“By studying people who had their thymus removed, we discovered that the thymus is absolutely required for health. If it isn’t there, people’s risk of dying and risk of cancer is at least double,” says senior author David T. Scadden, MD, director of the Center for Regenerative Medicine at MGH and co-director of the Harvard Stem Cell Institute. “This indicates that the consequences of thymus removal should be carefully considered when contemplating thymectomy.”
In an additional analysis involving all patients in the thymectomy group with more than five years of follow-up, the overall mortality rate was higher in the thymectomy group than in the general U.S. population (9.0% vs 5.2%), as was mortality due to cancer (2.3% vs 1.5%).
Although Scadden and his colleagues found that the risk of autoimmune disease did not differ substantially between the thymectomy and control groups as a whole in their study, they observed a difference when patients who had infection, cancer, or autoimmune disease before surgery were excluded from the analysis. After excluding these individuals, 12.3% of patients in the thymectomy group developed autoimmune disease compared with 7.9% in the control group, for a 1.5-times higher risk.
In the subgroup of patients in whom T cell production and immune-related molecules were measured (22 in the thymectomy group and 19 in the control group, with an average follow-up of 14.2 postoperative years), those who had undergone thymectomy had consistently lower production of new T cells than controls and higher levels of pro-inflammatory molecules in the blood.
Scadden and his team now plan to assess how different levels of thymus function in adults affect individuals’ health. “We can test the relative vigour of the thymus and define whether the level of thymus activity, rather than just whether it is present, is associated with better health,” he says.
