| Abstract |
The scope of this study was to evaluate the role of sleeve gastrectomy in
the gastrointestinal motility, with special emphasis in the motility of the stomach
and the small bowel until the food reaches the large bowel through the cecum.
Sleeve gastrectomy is a popular surgical procedure which leads to
successful weight loss and improves the metabolic profile of the patient. Recent
evidence supports the acceleration of the gastric emptying after the operation
but there are not detailed studies on the effects caused in the global motility of
the upper gastrointestinal system and especially of the small bowel.
In the present study participated twenty one morbidly obese patients
planned to have a laparoscopic sleeve gastrectomy (13 females and 8 males).
Their gastrointestinal transit times were recorded before and four months after
the operation. Also seventeen lean matched controls (9 females and 8 males)
were studied with the same method aiming to use their values as refenence.
For the purposes of this study all the participants consumed a
standardised and radiolabeled meal after overnight fasting The meal consisted of
120 g of scrambled eggs, fried with 10 g of butter; 2 slices of white bread (120 g);
and 150 mL of water, and was consumed over 10 minutes. This semisolid meal
contained 358 kcal with 50% fat, 30% carbohydrates, and 20% protein. The egg
white was labelled with 1 mCi 99mTc sulfur colloid (Phytacis CIS;Bio
International, Gif‐Sur‐Yvette, France). The selection of the meal type was done
according to the consensus recommendations of the American
Neurogastroenterology and Motility Society and the Society of Nuclear Medicine
for the gastric scintigarphy stidies. (Consensus Recommendations for Gastric
Emptying Scintigraphy: A Joint Report of the American Neurogastroenterology
and Motility Society and the Society of Nuclear Medicine Am J Gastroenterol
2008;103:753‐63).
Imaging was performed with a dual‐head gamma camera (Philips Forte;
Jet Stream Medical Systems, CA), immediately after the completion of the meal.
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With that way static images with the patient in an upright position were
acquired for quantitative evaluation.
A dedicated system (Xeleris, 2.1753; GE Medical Systems,Milwaukee, WI)
was used for the quantitative analysis of the performed images. Every image was
analyzed by manually drawing regions of interest (ROIs), separately enclosing
the stomach, the area corresponding to the entire small intestine, the area of
terminal and the area of the cecum.
Total counts were extracted from anterior and posterior images and
were used to calculate the geometric mean , which represents the total sum of
the counts for each time point.
Quantitative parameters calculated are defined as follows:
Time of 10% gastric emtying (Τ Gastric lag = TG lag): Time interval during
which gastric emptying is 10% of the initial meal volume consumed.
Time of 1/2gastric emptying (T Gastric ½ = TG ½): Time interval between
the completion of the meal and the point at which half of the meal has left the
stomach
Time intestinal max (Intestinal T max = Τ Int max): Time needed for the meal
to leave the stomach get accumulated in the small intestine before the latter
starts emptying in the large intestine.
Time terminal ileum 10% (T Ileum 10% = Τ Il 10%): Time interval from the
meal completion to the point at which 10% of the total maximum counts appear
in the terminal ileum.
Time of cecal filling initiation (T Cecal filling initiation = T Cf in ): : The time
from meal completion to the initiation of terminal ileum emptying to the cecum
Time of Duodenal to ileum transit (T Duodenum to Ileum transit = T DIt):
Food transit time from the duodenum to the terminal ileum was calculated by
subtracting the T gastric 10% from T ileum 10% (T ileum 10% − T G lag
Time of Ileocecal valve transit ( T Ileocecal Valve transit = T ICVt): The
time required for food particles to cross the ileocecal valve was calculated by
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subtracting the Tileum 10% time from the cecal filling initiation time (T Cf in ‐ T
Il 10%).
The statistical analysis of data was performed using the statistical software
package MedCalc 12.1.4. (MedCalc, Mariakerke, Belgium) Values were presented
as median and range. Differences between clinical parameters before and after
surgery were examined using a paired Wilcoxon rank sum test. Correlation of
parameters was performed through a Spearman rank correlation coefficient. The
level of significance was set at P < 0.05.
The results of those measurements can be summerised as follows:
Gastric emptying
As in previous studies,the gastric emptying of a semisolid meal was found
to be characterized by a lag phase that represented the time needed for the solid
food to be triturated into small particles that were then passed through the
pylorus. This same phase indicates the time from the end of the meal to the
initiation of emptying into the duodenum and small intestine. The TG lag was
found to be significantly accelerated after sleeve gastrectomy from 15.5 minutes
(range, 6.5–24.2 min) preoperatively to 8.4 minutes (range, 3.0–22.4)
postoperatively (P < 0.05). The TG ½ was also found to be accelerated
significantly postoperatively from 61.7 minutes (range, 37–94.3 minutes)
preoperatively to 49.1 minutes (range, 22.4–92.1 minutes) postoperatively (P <
0.05).
Furthermore in the lean controls the TG lag was 17.7 min (range 7.3 ‐ 24.6
min). It was found to be longer that the TG lag of the obese patients
preoperatively but the difference found was not statistically significant (p =
0.19). Contrary after the operation with the additional acceleration of the TG lag
in the postoperative obese patients, the difference with the TG lag of the lean
controls becomes statistically significant (P<0.05).
Similar differences have been noted in the TG ½ that was 73.4 min in the
lean ontrols (range 34.6 – 104.3 min). This time was longer than the TG ½ of
61.7 min of the non operated obese patients but this difference ,despite reaching
statistical significance in the females (P<0.05), in the total group of patients
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onluy showed a strong trend ithout satisfying the criteria for statistical
significance (P=0.07). Contrary after the ignificant acceleration of the TG ½ in
operated obese subjects (TG ½ = 49.1) the difference with the TG ½ of the lean
controls reaches statistical significance (P<0.05).
Motility of the small bowel
T intestinal max was also found to be accelerated after SG from 141.5
minutes in the obese group preoperatively (range, 86–218 minutes) to 110.5
minutes (range, 49–175 minutes) postoperatively (P < 0.05). The filling of the
small bowel in the lean controls which have a T Int max of 174 min (range 100 –
262 min), is happening more slowly from the non operated obese (p<0.05) as
well as from the operated obese subjects (p<0.05).
The Τ Il 10%, which corresponds to the initiation of filling of the terminal
ileum from the completion of the meal, was found to be accelerated in the obese
group after sleeve gastrectomy from Τ Il 10% 95 min (range 47 ‐160 min)
preoperatively was reduced to 78 min (range 30‐124 min) postoperatively
,(p<0.05). In the lean controls the initiation of filling of the terminal ileum with a
Τ Il 10%,of 120 min (range 18‐180 min), is happening more slowly from the
filling in the obese non operated group but this difference is not reaching
statistical significance in the total group of patients (p=0.07) but only in the
subgroup of females (p<0.05). Additionally with the acceleration of the Τ Il 10%,
in the obese group postoperatively (78 min), the difference with the already
delayed imitation of filling of the terminal ileum of the lean group (120 min)
becomes statistical significant (P<0.05).
The small bowel transit time (duodenal to terminal ileum transit) was
found to be accelerated after SG from 71.8 minutes (range,38–141 minutes)
preoperatively to 62.6 minutes (range 25–118 minutes) postoperatively (p 7lt;
0.05). The same Time in the lean controls with Τ DΙt 103.4 min (range 40.3 –
163.2 min) is slower from the Τ DΙt of the obese preoperatively but without
statistically significance (p=0.12) while it is significantly slower from the Τ DΙt of
the obese postoperatively (p,0.05).
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Cecum and cecal filling initiation
On the contrary the initiation of the filling of the cecum from the meal
completion (Τ Cf in) was found to be delayed in the obese group after the sleeve
gastrectomy: from 182 minutes preoperatively (range, 120–275 minutes) to 210
minutes (range, 142–310 minutes) postoperatively (p < 0.05). In the lean
controls the cecal filling initiation corresponds to a Τ Cf in of 223 min (range
122‐320 min) and while this Time is significantly slower from that of the obese
non operated group (p,0.05), it has no difference from the values seen in the
obese group postoperatively (p=0.15).
In addition, the ileocecal valve transit time (T ICVt) was also found to be
delayed after sleeve gastrectomy from 102 minutes (range, 27–275 minutes)
preoperatively to 126 minutes (range, 75–310 minutes) postoperatively (p <
0.05). In the lean controls the transit time through the ileocecal valve
corresponds to 101 min (range 50‐165 min) and while this is not different from
the T ICVt of the obese group preoperatively (p=0.62), it is significantly delayed
in the obese group postoperatively (p7lt;0.05).
Table with Summary of Results
The values correspond to the median value of the measurements while between brakets is the
range. All the times are expressed in minutes. Values marked with an * indicate difference with p <0.05
between preoperative and postoperative values in the obese group while ** indicate a difference of p<0.05
between obese and lean controls and *** between obese postoperatively and lean controls.
Time
Minutes
Obese
Preoperatively
Obese
Postoperatively
Lean
Controls
TG lag 15.5 (6.2‐24.2) 8.4 (3.0‐22.4)* 17.1 (7.3‐24.6)***
T G ½ 61.7 (37.0‐94.3) 49.1 (22.4‐92.1)* 73.4 (34.6 – 104.3)***
T Int max 141.5 (86.0‐218.0) 110.5 (49.0‐175.0)* 174.0 (100.0‐262)**,***
T Il 10% 95.0 (47.0‐160.0) 78.0 (30.0 ‐124.0)* 120.0 (18.0‐180.0)***
DTIt 71.8 (38.0‐141.0) 62.6 (25.0‐118.0)* 103.4 (40.3‐163.2)***
T Cf in 182.0 (120.0‐275.0) 210.0 (142.0‐310.0)* 223.0 (122.0‐320.0)**
ICVt 102.0 (27.0‐275.0) 126.0 (75‐310) * 101.0 (50.0‐165.0)***
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Conclusively the present study shows that sleeve gastrectomy is causing
acceleration of the gastric emptying as well as independent acceleration of of the
small bowel motility, while at the same time is causing delay of the transit of the
enteric content through the ileocecal valve. In the group of the lean controls it
seems that their stomach has a trend to empty more slowly comparing to the
obese and respectively they have a slower filling of the small bowel, slower
transit of the food through the small intestine and slower arrival to the terminal
ileum. This could potentially lead to more protracted feeling of satiety and less
cravings for food in the lean controls. As far as the initiation of filling of the
cecum and the transit of the ileocecal valve are concerned, there are no
differences found between the obese and lean individuals.
Based on these observations and in contrast with what somebody would
have expected, laparoscopic sleeve gastrectomy causes changes in the motility of
the stomach and the small bowel, that intensify instead of abolishing the
differences with the lean controls causing even greater acceleration of food’s
transit in its way from the stomach to the terminal ileum. But precisely at this
point the operation acts by delaying the transit time through the ileocecal
valve. The initiation of cecal filling and the transit time trough the ileocecal valve
are the only parameters of the gastrointestinal motility that simulate after the
operation between the obese and the lean group. Therefore the operation
accelerates the passage of the food from the stomach to the terminal ileum and
then prolongs its stay to that area by delaying the exit through the ileocecal vale.
With that way an earlier and protracted contact of the food with the
terminal ileum mucosa is achieved and that observation supports the hypothesis
that neurohormonal changes happening after sleeve gastrectomy are able to
modify the function of the gastrointestinal tract as a all and thus improve the
patient’s metabolic profile even before any substantial weight loss. However
there is a need for further studies in order to clarify the exact hormonal and
neuro‐mechanical changes that are happening after this operation.
In conclusion the findings of the present study indicate that sleeve
gastrectomy leads to weight loss by causing complex modifications in the
physiology of the gastrointestinal tract as it induces changes not only to the
functioning of the stomach but also to the global functioning of the
gastrointestinal tract in palces that are anatomically remoted from the operative
field.
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Καταγραφή του χρόνου διάβασης της τροφής απο το ανώτερο πεπτικό πριν και μετά λαπαροσκοπική επιμήκη γαστρεκτομή
