Sleeve plus diversion

This blog provides free general information for anyone who is seeking to understand more about the limitations on the laparoscopic sleeve gastrectomy and one variation of the sleeve called the SASI, not intended as a medical consult. Please seek proper medical advice for individual assessment and management.

Please also read the section on sleeve or gastric bypass as well for more information.

Please note this procedure is not common and not recommended for the super morbid obese patients with diabetic patients at this stage.





The ideal bariatric procedure:

  • Achieve excellent long term sustained weight loss result with no weight regain.
  • Offers the most successful resolution rate for medical co-morbidities (such as hypertension, Type 2 diabetes mellitus, dyslipidaemia, obstructive sleep apnoea, etc)
  • Has no side effects or complications.
  • Has no weight loss failure rates or weight regain.

Obviously this does not exist as all bariatric procedures have their disadvantages, short comings, failures and complications.


In reality all the current bariatric surgical procedures have:

  • Limited weight loss results (most patients will never get down to a BMI of 25)
  • Some patients do not achieve adequate weight loss (failure of weight loss, achieving <50% excess weight loss (%EWL)).
  • Some patients regain most of the weight lost several years later (weight recidivism).
  • There may be partial or no resolution of obesity related medical co-morbidities (such as hypertension, T2DM, dyslipidaemia, OSA, etc).
  • All surgical procedures have potential post op risk and complications (serious ones include leaks, fistula, bleeding, pulmonary embolism) and a mortality rate.
  • All surgical procedures have potential long term complications (which may include marginal ulcers, protein calorie malnutrition, vitamin/trace mineral deficiencies, etc).
  • Some have may have side effects such as acid/bile reflux, dumping and diarrhoea, etc impairing quality of health or functional quality of life.


The ideal bariatric procedure does not exist.

  • A purely restrictive surgery has the least successful outcome.
  • A combination of restriction and the ability to manipulate the neuro-endocrine signals to control hunger and achieve longer satiety is more desirable than just purely restriction.
  • A malabsorptive procedure has the best weight loss result but the more aggressive the primary procedure, the higher the risk, side effects and complications.



Weight loss results after bariatric surgery


Patients falls into 3 categories after bariatric surgery.

  • Primary responder are patients who achieved >50% EWL
  • Primary non responder are patients who achieved <50% EWL (previously called failure of weight loss)
  • Secondary non responder are primary responders with successful weight loss in the past but has regained the weight lost
    • Mild regain is 5-10kg from the nadir
    • Severe regain is >10kg from the nadir



Weight regain are often multifactorial and difficult to study.

In a simplistic explanation, they may be grouped as:

  • Technical failure (eg. dilated proximal gastric pouch or loss of restriction and increased food portion size)
  • Hormonal changes (eg, rise in ghrelin, loss of satiety)
  • Nutritional non-compliance (eg. non adherence to dietician dietary plans, sweet eating)
  • Behavioural non-compliance (eg. grazing, emotional eating habits)
  • Inadequate physical activity
  • Psychological factors






Weight regain after weight loss surgery


Weight regain will occur after bariatric surgery with time.

Weight regain may be associated with the return of medical co-morbidities (hypertension, T2DM) and reduced health related quality of life


It is estimated that patient will regain 5-10% of their total weight loss (TWL) within the first decade after bariatric surgery


The percentage of patients who develop weight regain after a sleeve gastrectomy and RYGBP may occur up to 76-87% or more.




Diabetes control after bariatric surgery


It is also noted that  bariatric surgery may halt the progression of T2DM, which is a chronic progressive disease, it is not necessarily about achieving a life-long cure.


Secondly patients with relapse or persistence of T2DM were more better managed and glycaemic control is easier after a sleeve gastrectomy.

  • The restriction in calorie intake allows patients to reduce the medication doses for oral hypoglycaemics or insulin, as proven with better HbA1C blood tests results compare to patients who had medical treatment alone and did not have bariatric surgery.


The success in treating T2DM often depends on other factors, such as:

  • Advanced age of the patients
  • Duration of the T2DM
  • Whether patients are requiring or dependent on insulin
    • In other words the ability of pancreatic Beta cells to recover, to regenerate/release insulin




Patients are divided into 4 categories depending on their response after bariatric surgery.


Complete remission

  • Defined as baseline blood glucose <100 mg/dL (5.6 mmol/L) and a HbA1C <6%, maintained for > 1 year without hypoglycaemic medications

Partial remission

  • Defined as baseline blood glucose 100 – 125 mg/dL (5.6 – 6.9 mmol/L) or a HbA1C 6-6.5% without hypoglycaemic medications or those who have not discontinued hypoglycaemic medications


  • Are patients who satisfied the criteria to define complete remission for more than 1 year but had recurrence of the diabetes, diagnosed as fasting glucose >126 mg/dL (7 mmol/L) or frank diabetes on oral glucose tolerance test >200 mg/dL (>11mmol/L) at 120 minutes


  • Are patients who did not have characteristics necessary to define complete remission for a duration >1 year





Many different types of bariatric surgery are available


This is why there are so many different surgical options available to patients in order to deal with some of the insufficiencies with bariatric surgery procedures, described above.



Some of the more common operations include:

  • Laparoscopic sleeve gastrectomy
    • Laparoscopic sleeve gastrectomy with transit partition
    • Single anastomosis ileal bypass (SASI)
  • Laparoscopic one anastomosis gastric bypass (OAGB)
  • Laparoscopic Roux Y gastric bypass (RYGBP)
    • Laparoscopic proximal RYGBP
    • Laparoscopic long limb gastric bypass
    • Laparoscopic distal RYGBP
  • Laparoscopic single anastomosis duodeno-ileal bypass with sleeve gastrectomy (SADI-S)


No doubt there will be many more variations of the above surgeries in the future, with more research and more innovative ways to achieve a better sustained long term weight loss result, more successful resolution of medical co-morbidities (hypertension, T2DM, dyslipidaemia, OSA, etc), with less nutritional side effects and surgical complications.




Sleeve gastrectomy with transit partition


This was first described by Santoro, a Brazilian surgeon in 2003 for obese patients with Type 2 diabetes mellitus. This is similar to a duodenal switch but does not completely exclude the duodenum.




Sleeve gastrectomy with single anastomosis sleeve ileal (SASI) or single anastomosis gastro-ileal bypass bypass (SAGI) with no sleeve gastrectomy


This is different to the one anastomosis gastric bypass (OAGB) or the sleeve gastrectomy with single anastomosis duodeno-ileal bypass (SADI-S) because it does not exclude the distal stomach or duodenum.

  • Post op gastroscopy and ERCP is still possible in the future.


This is a simplified modification of the transit partitioning.

  • There is a single loop anastomosis instead of a Roux Y reconstruction or double anastomosis.
  • The sleeve gastrectomy may be performed starting from 6cm proximal to the pylorus or the remnant stomach may be left behind (without the sleeve resection).
  • A loop of small bowel 250cm proximal to the ileo-caecal valve is brought up to the distal antrum to do the gastro-jejunostomy, the diameter of the anastomosis is usually <3cm.


The restriction from the sleeve is combined with rapid nutrient flow and intense distal gut stimulation.

  • The distal gut hormone GLP-1 is released earlier for the central satiety effects and to reduce gastric emptying, called the ileal brake phenomenon.


The SASI procedure offers the combination of a restrictive procedure plus neuro-modulation to promote the metabolic effects of the procedure, similar to the SADI-S (but the anastomosis is proximal to the gastric pylorus).

  • The disadvantage include the risk to develop bile reflux, marginal ulcers.


Some studies report 64% excess weight loss at 12 months, better than the sleeve but less than the RYGBP.

  • However it must be said that SASI is performed to achieve better glycaemic control rather than to achieve more weight loss in a non-diabetic patient.
  • It is not known if this is a good rescue operation for a failed primary sleeve gastrectomy.




Sleeve gastrectomy with single anastomosis sleeve jejunal (SASJ) anastomosis/bypass


This is very similar to the SASI described above.


The sleeve gastrectomy is created first followed by a side-side gastro-jejunal anastomosis, 150cm distal to the DJ flexure (the bilio-pancreatic limb is similar to the OAGB) in order to avoid the nutritional side effects of the SASI.






These operations are all still fairly new, will need to be studied and refined before it can be recommended.

  • Time will tell whether these procedures will be a good idea (perhaps not as a primary procedure to replace the sleeve gastrectomy but definitely worth considering as a revisional procedure).


It does reveal the ingenious ideas and new innovative surgical techniques that researchers can come up with by combining the restriction and malabsorptive type operations.


In other words a hybrid of the sleeve, gastric bypass and SADI-S but making the operations technically easier to perform and hopefully prove to have less side effects or complications than the index procedure.