I. INTRODUCTION

The length of the small intestine varies from 3 to 8.5 meters. The average length is considered to be approximately 5 meters(1).

The variation in the intestinal length in humans is a topic of interest. Differences in measurement techniques, small study groups, and large interindividual variation have contributed to the uncertainty associated with defining a normal range of intestinal length. Estimation of small bowel length is relevant for many years to plan small bowel resections as the development of malabsorption is closely related to the total length of small intestine that remains after surgery (2,3).

Measurement of small bowel length is relevant in planning bariatric surgery because the efficacy and incidence of malnutrition are closely associated with the length of the bilio-pancreatic (BP) limb, the common channel, and the total length of the small bowel. This advancement in knowledge regarding bariatric surgery has generated renewed interest in the importance of the length of the small bowel in this patient population(4,5).

Despite its great importance in surgical approaches, little definitive information is available on human gut tract length in Egyptian population. Previous studies have correlated small bowel length with various measures like sex, age, weight, height and ethnic background. Better knowledge of these relationships may aid in avoidance of surgical complications (6).

Prediction of the total small bowel length (TSBL) could be useful to avoid intraoperative measurements, which might consume extra time particularly in laparoscopic procedures in morbidly obese individuals. A CT scan-based prediction method has been proposed in the literature but without validation. There is significant controversy on the role of anthropometry as predictive parameters to the total small bowel length(TSBL)(7,8).

II. PATIENTS AND METHODS

We conducted a prospective cross section study that included 160 patients (100 males, 60 females) presented to KasrAlainy hospital with indication for open abdominal exploration.

a) Inclusion criteria

Adult Patients aged $\ge 18$ years, presenting with indication for open abdominal exploration such as blunt or penetrating abdominal trauma, Incarcerated or strangulated para umbilical hernia.

b) Exclusion criteria

Patients aged less than 18 years. Patients presented with gastrointestinal tract malignancy. Patients presented with Peritonitis. Patients with history of Previous abdominal operation to avoid intestinal adhesions which may affect the proper measurement of the small bowel length.

Study procedures: All Patients enrolled in our study were be assessed on admission:-

History Taking, hemodynamic assessment, general and abdominal examination.

Imaging: X ray (chest erect and abdomen), ultra sound and CT.

Laboratory investigations: CBC, Na, k, urea, creatinine, ALT, AST, RBS and HbA1C.

Unstable cases such us abdominal stab with eviscerated bowel or Full from height will be rushed to the Operating room.

Intraoperative findings: Measurement the of the small bowel was expressed in centimeters, starting at ligament of Treitz and ending at the ileocecal junction, using a sterile 10 cm- tape applied to the anti-mesenteric border of un stretched small intestine.

Spasmolytic (visceralgine 5 mg/2 ml IV) was taken on induction of anesthesia to reduce the contractions of the small bowel.

All measurements were obtained by 2 trained surgeons to increase the accuracy of measurement.

III. RESULTS

The study included 60 females and 100 males representing $37.7\mathrm{\%}$ and $62.3\mathrm{\%}$, respectively, of the study population. The mean age was $46.34\pm 16.022$ years, weight $=80.49\pm 8.302\mathrm{kg}$, height $=170.13\pm 9.150\mathrm{cm}$, and BMI $=28.02\pm 4.112\mathrm{kg}/{\mathrm{m}}^2$. The measurement of the TSBL in the study participants yielded a mean of $412.62\pm 54.938\mathrm{cm}$ ranging from 310 to $560\mathrm{cm}$ as shown in Table (1).

Table (1): Descriptive statistics of the quantitative baseline variables assessed for this study

a) Causes of admission

Patient admitted were mainly due to stab abdomen 32 patients $(20\mathrm{\%})$, Incarcerated Para umbilical hernia 21 patients $(13.12\mathrm{\%})$, Road Traffic

Accident 19 patients $(11.87\mathrm{\%})$, Fall from height 18 patients $(11.25\mathrm{\%})$, Incarcerated inguinal hernia 12 patients $(7.5\mathrm{\%})$, Mesenteric Vascular Occlusion 10 patients $(6.25\mathrm{\%})$ as shown in Table (2).

Table (2): Causes of admission among the included patients

Table (3) shows that correlation between total small bowel length (TSBL) and the measured variables in the study and it show that there was very high positive

Table (3) shows that correlation between total small bowel length (TSBL) and the measured variables in the study and it show that there was very high positive correlation according to weight and height while BMI shows no significant correlation between them.

Table (3): Correlation between TSBL and the measured variables in the study

Table (4): Comparison between gender groups according to baseline variables assessed for this study

Table (4) shows that comparison between gender groups according to baseline variables assessed for this study and it show highly statistically significant differences between sex groups according to age, height, BMI and total small bowel length (TSBL).

Table (5): Correlation between total small bowel length (TSBL) and the measured variables in male

Table (5) shows correlation between total small bowel length(TSBL) and the measured variables in male and it shows that there was very high positive significant correlation according to weight and height.

Table (6): Correlation between total small bowel length(TSBL) and the measured variables in female

Table (6) shows correlation between total small bowel length (TSBL) and the measured variables in female and it shows that there was very high positive significant correlation according to height.

IV. DISCUSSION

Regarding the quantitative baseline variables assessed for this study, our results showed that there were 60 females and 100 males representing $37.5\mathrm{\%}$ and $62.5\mathrm{\%}$, respectively, of the study population. The mean age was $46.34\pm 16.022$ years, weight = $80.49\pm 8.302$ kilograms, height = $170.13\pm 9.150$ centimeters. The measurement of the TSBL in the study participants yielded a mean of $412.62\pm 54.938$ cm ranging from 310 to $560$ cm.

Compared this study to others, according to ethnic background. The current study was supported by Bekheit et al. (9) conducted on Egyptian population, reporting the normal total bowel length in living adult humans and correlation with the anthropometric parameters. This study included 606 participants (380 females and 226 males). Their mean age was $39.8\pm$ years, the mean TSBL was $630\pm 175$ cm ranging from 250 to $1300$ cm.

Also, the study by Almalki et al. (10) conducted on Taiwanese patients, mean age was $38.6\pm 12.0$ years and BMI was $38.9\pm 7.6$. Small bowel length varied widely among patients (mean $739.8+115.7$ cm, range $380-1050$ cm). Compared to Egyptian population in our study ranging from 310 to $560$ cm. It is possible that

Asian people have longer small bowel length than people of other races.

As well the study by Tacchino, et al.(11) aimed to evaluate small bowel length (SBL). The study enrolled 443 Italian patients out of them 342 were females $(78\mathrm{\%})$. The mean age was $37.7\pm 10.4$ years, the mean SBL of 443 patients undergoing laparotomy was $690\pm 93.7$ cm (range 350-1049 cm). also, greater than mean small bowel length in Egyptian population. Compared to our study, Varut et al., (12) aimed to Evaluate the length of small bowel (SB) in Thai patients, the study enrolled 48 patients. There were 27 men and 21 women, with an average age of 60 years (range 28-88). The average length of SB was $428\pm 105$ cm (range 169-745).

Also, Raines et al., (13) aimed to estimate of small bowel length. The study enrolled 91 French patients, with male/female ratio of 51/40, the mean BMI was $29.45\pm 8.38$. Small bowel length was found to vary widely between individuals (average 998.52 cm, range 630-1510 cm).

Furthermore, Teitelbaum et al. (14) aimed to present a series of intraoperative SBL measurements taken in North American patients undergoing laparotomy. Specific attention is paid to analyzing potential patient-specific predictors of SBL. The study enrolled 240 patients. 127 patients were female $(53\mathrm{\%})$. The mean age was 55 (range 20-86) years, mean height was 169 (range 138-196) cm and mean weight was 77 (range 41-175) kg. Mean SBL from the ligament of potential patient-specific predictors of SBL. The study enrolled 240 patients. 127 patients were female (53%). The mean age was 55 (range 20-86) years, mean height was 169 (range 138-196) cm and mean weight was 77(range 41-175) kg. Mean SBL from the ligament of Treitz to ileocecal value was $506\pm 105$ (range 285-845) cm.

Compared to previous studies, our study predict that the Egyptian population has shorter mean small bowel length (SBL), $412.62\pm 54.938$ cm ranging from 310 to 560 cm. compared to other populations of different ethnic background. Regarding the correlation between total small bowel length(TSBL) and the measured variables in the study, we found that there was very high positive correlation according to weight and height while BMI shows no significant correlation between them.

The study by Bekheit et al. (9) reported that there was very weak (i.e., negligible) positive but statistically significant correlation between the total small bowel length (TSBL) and both weight and height. There was no significant correlation between the TSBL and BMI or the age on the other hand. This was partially agreed with our results.

Also, supporting our study, Almalki et al. (10) in linear regression analysis revealed a significant association between small bowel length and body height, body weight, and waist circumference, but not significantly correlated with age.

As well, Tacchino et al. (11) in multivariate linear regression analysis model to predict SBL reported that sex, age, height, and weight showed a significant correlation .

The study by Purandare et al. (15) reported that there was no significant correlation between BMI and TSBL.

In addition, Raines et al., (13) in a linear regression analysis demonstrated a statistically significant relationship between small bowel length and height (regression coefficient = 0.0561, P-value = 0.0238). A linear relationship between small bowel length and weight or BMI was not observed.

As well, Teitelbaum et al., (14) reported that height was positively associated with increased SBL . A multivariate linear regression model using patient sex, age, height and weight was significant $(P=0.001)$ and the predictors explained $8\mathrm{\%}$ of the variance in SBL. In this model, only height was independently predictive of increased SBL $(P=0.03)$. This was partially agreed with our results.

Hosseinpour et al. (16) reported that there was no significant correlation between height and small intestinal length.

Comparison between gender groups according to baseline variables assessed for this study showed that there were highly statistically significant differences between sex groups according to age, height, BMI and

TSBL. where TSBL was significantly longer in males compared with females.

However, the study by Bekheit et al. (9) on the assessment of the gender influence on the various anthropometric measures and the total small bowel length (TSBL), reported that males had significantly higher weight and were significantly taller compared with females. There was no difference in the BMI or age between males and females. However, the total small bowel length (TSBL) was significantly longer in males compared with females. The mean TSBL in males was $661.5\pm 186$ cm versus $612\pm 164$ cm. They also noted that the correlation between TSBL and height is stronger in males than females but with no statistical difference. This comes in agreement with our study (17).

Also, in agreement with our results Almalki et al. (10) reported that there was statistically significant association between sex and small bowel length.

Similarly, the study by Teitelbaum et al. (14) reported that Male sex and height had positive correlations with SBL. In men, height had a positive association with SBL ( $r=0.20$, $P=0.03$ ), whereas in women there was no correlation between height and SBL ( $r=0.06$, $P=0.51$ ). In men, age had a trend toward a positive correlation with SBL ( $r=0.17$, $P=0.08$ ), whereas in women age was negatively correlated with SBL ( $r=20.18$, $P=0.04$ ). A multivariate linear regression model using sex, age, height and weight to predict SBL was significant ( $P=0.001$ ) and explained $8\mathrm{\%}$ of the variance in SBL. Increased height was the only significant independent predictor of increased SBL ( $P=0.03$ ) in this model.

Similar results were reported by recent study conducted by Hosseinpour and Behdad A. (16) where mean intestinal length was longer in females $(468\mathrm{cm})$ than males $(459\mathrm{cm})$. On the contrary, studies conducted by Nordgren et al. (18) and Teitelbaum et al. (14) reported that males had longer intestinal length than females.

V. CONCLUSION

Length of the small bowel in humans is pertinent to advances in deep enteroscopy and existing surgical applications such as intestinal bypass and prevention of short gut syndrome. The current study showed that the mean total small bowel length (TSBL) in the studied cases was $412.62\pm 54.938$ cm ranging from 310 to $560$ cm. Which was lower than average small bowel length (SBL) of other population of different ethnic background, the current study showed that there was very high positive correlation according to weight and height while BMI shows no significant correlation between them. We also found that there were highly statistically significant differences between sex groups according to age, height, BMI and TSBL. In males, there was very high positive significant correlation according to weight and height. In females, there was very high positive significant correlation according to height.