Some people who have weight loss surgery develop serious malnutrition problems where their bodies don’t get enough protein and nutrients. This report describes two patients who had a specific type of weight loss surgery called SADI-S that led to severe malnutrition. Doctors had to perform a second surgery to fix the problem. After the conversion surgery, both patients recovered well and no longer needed special feeding tubes. This case study shows that when weight loss surgery causes serious nutritional problems, a second surgery can help restore normal nutrition, though doctors still need more research to develop standard treatment guidelines.

The Quick Take

  • What they studied: Can a second surgery fix severe malnutrition that develops after a specific weight loss surgery called SADI-S?
  • Who participated: Two patients who had weight loss surgery (SADI-S) and then developed serious malnutrition requiring special feeding support
  • Key finding: Both patients recovered from severe malnutrition after having a second surgery to modify how their digestive system works, and they no longer needed special feeding tubes
  • What it means for you: If someone develops serious malnutrition after SADI-S surgery, a second surgery may help restore normal nutrition. However, this is based on only two cases, so more research is needed before this becomes standard treatment

The Research Details

This is a case report and literature review, which means doctors described what happened to two specific patients and reviewed what other doctors have written about similar situations. The two patients both had weight loss surgery called SADI-S (a procedure that makes the stomach smaller and changes how food moves through the intestines). Both developed severe malnutrition afterward, meaning their bodies weren’t absorbing enough protein and nutrients. They required parenteral nutrition, which is special nutrition delivered through an IV directly into the bloodstream, bypassing the digestive system. The doctors then performed a second surgery to change how their intestines were connected, making the path longer so food would spend more time being absorbed.

This research matters because SADI-S is becoming more popular for weight loss, but doctors are discovering it can sometimes cause serious nutritional problems. Understanding how to fix these problems is important for patient safety. The case report approach allows doctors to describe detailed patient stories and outcomes, which can guide future research and treatment decisions.

This is a small study with only two patients, so the findings are limited. Case reports are useful for describing unusual situations and generating ideas for future research, but they cannot prove that a treatment works for everyone. The authors acknowledge that more research is needed to develop standard treatment guidelines. Readers should understand this represents two specific cases, not proof that this surgery works for all patients with this problem.

What the Results Show

Both patients developed severe protein malnutrition after their SADI-S surgery, with blood protein levels dropping to dangerously low levels (1.6-1.8 g/dL, when normal is around 3.5-5.0 g/dL). Both required parenteral nutrition—special nutrition delivered through IV—to survive. After the doctors performed a second surgery to lengthen the path food travels through the intestines (increasing the common channel from 200-250 cm to 550-750 cm), both patients recovered completely. They no longer needed the special IV nutrition and their blood protein levels returned to normal. The second surgery was performed using minimally invasive laparoscopic techniques, meaning smaller cuts and faster recovery compared to traditional open surgery.

The doctors noted that their surgical technique had advantages over other possible approaches: it was less complicated to perform, avoided difficult problems with managing the duodenum (first part of small intestine), and achieved excellent nutritional recovery. Both patients tolerated the conversion surgery well without major complications. The authors reviewed existing literature and found limited information about how to best manage malnutrition after SADI-S, suggesting this is an emerging problem that needs more attention.

SADI-S is a newer weight loss surgery compared to more established procedures like gastric bypass. While SADI-S can be effective for weight loss, this case report adds to growing evidence that it carries a higher risk of malnutrition compared to some other weight loss surgeries. The authors note that standardized protocols for fixing SADI-S complications don’t yet exist, meaning doctors are still learning the best approaches. This case report contributes to that learning process.

This study has significant limitations: only two patients are described, so results cannot be generalized to all patients. There is no comparison group, so we cannot know if other surgical approaches might work better or worse. The follow-up time after surgery is not clearly specified. Because this is such a small case report, it cannot prove this surgery is the best solution—it only shows it worked in these two cases. More research with larger numbers of patients and longer follow-up is needed.

The Bottom Line

Based on this limited evidence, conversion surgery may be considered for patients who develop severe malnutrition after SADI-S that cannot be managed with nutritional support alone. However, this recommendation is based on only two cases and should be discussed carefully with bariatric surgeons. Patients with SADI-S should be monitored closely for signs of malnutrition (weakness, hair loss, swelling, low blood protein levels) and work with nutritionists to prevent problems before they become severe.

This research is most relevant to: (1) people who have had or are considering SADI-S surgery, (2) bariatric surgeons who perform these procedures, (3) nutritionists who work with weight loss surgery patients, and (4) people who develop severe malnutrition after weight loss surgery. People with other types of weight loss surgery may have different risks and should not assume these findings apply to them.

In these two cases, recovery from the conversion surgery was relatively quick, with patients no longer needing special IV nutrition shortly after surgery. However, full nutritional recovery and return to normal eating may take several weeks to months. Realistic expectations should be discussed with your surgical team.

Want to Apply This Research?

  • Track weekly blood protein levels (albumin) and body weight if you’ve had SADI-S surgery. Also monitor for warning signs: unusual fatigue, hair loss, muscle weakness, or swelling in legs and feet. Log these observations weekly to share with your doctor.
  • Set daily reminders to take prescribed vitamin and mineral supplements exactly as directed. Use the app to log protein intake at each meal (aim for 60-100g daily) and track any digestive symptoms. Schedule monthly check-ins with your nutritionist through the app.
  • Create a long-term tracking dashboard showing: monthly weight trends, quarterly blood work results (protein levels, vitamins, minerals), daily protein intake, and symptom logs. Set alerts for concerning changes that warrant doctor contact. Compare trends over 3-month periods to catch problems early.

This case report describes only two patients and should not be considered proof that conversion surgery is the standard treatment for all cases of malnutrition after SADI-S. If you have had weight loss surgery and are experiencing symptoms of malnutrition (fatigue, weakness, hair loss, swelling), consult your bariatric surgeon or gastroenterologist immediately. Do not make decisions about surgery based solely on this report. All surgical decisions should be made in consultation with qualified bariatric surgeons who can evaluate your individual situation. This information is educational and not a substitute for professional medical advice.