From September 26, 2005 to May 28, 2009, 100 patients (sex ratio, females: males = 59:41 [1.4:1]) with a mean age of 43.6 years (range, 22–64) and a preoperative BMI of 52.3 kg/mm2 (range, 36–77) underwent SG. Operation was performed by three surgeons, operating as a team in all the 100 recorded operations. Patient's outcome and operation time were not influenced by changing the surgeon in these team. Demographic data are shown in Table 2 .
Operation Data Of the 100 patients, 99 underwent primarily laparoscopic surgery. In 6.1 % of these patients (6 of 99), a conversion from laparoscopy to laparotomy was necessary. In one case, a primary laparotomy was performed because of an abdominal wall hernia, resection of an anus praeter, subtotal colectomy with an ileorectostomy. Subtotal colectomy was performed due to the fact of several colon operations in an outside hospital. Postoperative course of the patient was uneventful. In 4 cases, this conversion was performed because of an insufficient laparoscopic overview with high intraabdominal pressure and in 2 cases due to the fact of laparoscopically uncontrollable bleeding ( Table 3 ).
The mean operation time was 86.4 min. The mean resected gastric volume was 995.6 ml. A 34-French calibration tube was used in 89 % of the patients (89). Staple line reinforcements were used in 88 % of the patients (88) ( Table 2 ). Comparing leakage rate and bleeding in patients using staple line reinforcement or oversewing was no difference.
There were significant differences among the durations of the OP. When staple line reinforcements were used, the mean OP duration was 79.3 min, compared to 141.1 min without using staple line reinforcements (p = 0.010).
A conversion to laparotomy was significantly more necessary for patients with a BMI > 60 kg/m2 compared to patients with a lower BMI (p > 0.001). The duration of the OP averaged 70.4 min for patients with a BMI between 35 and 39.9 kg/m2, 70.2 min for patients with a BMI between 40 and 49.9 kg/m2, 92.9 min for patients with a BMI between 50 and 59.9 kg/m2 and 101.2 min for patients with a BMI > 60 kg/m2. Patients with a BMI > 50 kg/m2 had significantly longer OP durations compared to patients with a BMI < 50 kg/m2 (95.7 vs. 70.2; p = 0.001). The resected gastric volume was significantly higher in patients with BMI > 50 kg/m2 compared to those with BMI < 50 kg/m2 (1072.7 vs. 854.2; p = 0.001).
Intraoperative and Early Postoperative Surgical Complications Twenty patients (20.0 %) suffered on intraoperative or/and postoperative complications ( Table 3 ). Postoperative complications occurred in 17 patients (17.0 %). One patient with BMI 55.5 kg/m2 died (1.0 %). At the tenth postoperative day patient complained of left upper abdominal pain. The CT scan showed an insufficient suture with a subcardial abscess. A CT-guided puncture ensued. Patient's cardiac situation worsened and ARDS developed. Acute complications were observed significantly more frequently in patients with BMI > 60 kg/m2 (p < 0.001). The major complication rate was 8 % ( Table 3 ).
Mortality Rate Mortality rate after 24 month of total follow up is 2 %. Above mentioned patient died during hospital stay 73 days after operation, due to SIRS and ARDS. Second patient died several months after SG in fact of his cardiac situation without any relation to operation.
Follow Up Data Follow up rate was 80 % (80/100). All of these patients were clinical examined with a laboratory test 24 months after SG, so mean follow up time is 24 months.
The mean preoperative BMI of all of the patients examined was 52.3 kg/m2. At the end of the follow up, there was a significant reduction in BMI to 35.4 kg/m2 (p < 0.0005). The greatest weight loss occurred within the first 12 postoperative months (52.3 kg/m2 to 36.3 kg/m2). Afterwards we observed a weight loss from 36.3 kg/m2 to 35.4 kg/m2 for all of the patients.
The %EWL in the BMI categories between 35 and 39.9 kg/m2 and 40 and 49.9 kg/m2 was 47.4 % and 47.5 %, respectively, after 3 months. The greatest %EWL in these categories was achieved after 12 (72.6 %) and 24 (74.2 %) months. Patient's with a BMI between 35 and 39.9 kg/m2 showed a slight tendency toward increased weight after this time. Patient's with a BMI between 40 and 49.9 kg/m2, 50 and 59.9 kg/m2 and over 60 kg/m2 showed continuous weight loss throughout the entire 24-month follow-up period ( Table 4 ). On average, there was a tendency toward increased weight after 18 months. The most significant weight loss was achieved within the first postoperative year (p < 0.0005). Regarding the percentage overweight loss, the highest %EWL of 67.1 % occurred after 18 months, and after 24 months, there was a further %EWL of 62.6 %. The highest %EWL of 83.3 % was observed in patients with a BMI between 35 and 39.9 kg/m2 after 12 and 18 months ( Table 4 ).
Revisional Procedures After SG Over the total observation period of 24 months, a second operation to induce weight loss was required in 25.0 % (25) of the patients to develop further weight loss or amelioration on comorbidities. Three patients underwent RYGBP and 22 patients DS.
Nutrient Deficiencies, Laboratory Parameters and Supplementation In patients after SG as a single step procedure a postoperative routine supplementation was not performed. Supplementation was suggested according laboratory examination performed every 6 months in case of deficiencies.
Iron Iron supplementation was performed in 48 patients (48.0 %). Seven of these patients developed microcytic anemia, which required the initiation of iron supplementation. In 23 of these 48 patients, iron supplementation was performed as prophylaxis after RYGBP or DS. The other 25 patients (25.0 %) 21 of them female were supplemented after SG. Further we examined iron supplementation in fertile woman. Women had a mean age of 42.8 years (25–59). Thirteen of these 21 women recorded a reduced iron value, and the other 8 women were supplemented with a combination of folic acid and iron.
Zinc The highest average value for zinc of 14.70 μmol/L was determined preoperatively (reference range: 10–23 μmol/L). There were no significant differences among the average values in the follow-up period. In total, 33 patients underwent zinc supplementation, and 5 of these complained of hair loss. Nineteen patients were supplemented after RYGBP or DS. Fourteen patients (14.0 %) were supplemented following SG due to zinc deficiency. For supplementation patients were given 15 mg Zink daily.
Selenium The highest average value for selenium of 81.60 μg/L (reference range: 50–120 μg/L) was determined preoperatively. After 3 months, a significant decrease to 61.13 μg/L (p < 0.0005) occurred. No other significant differences were observed over the course of the follow-up. Due to selenium deficiency in laboratory eight patients after SG were treated with selenium supplementation using 100 μg twice a day. Among the 75 patients who did not undergo a second operation, there was a gradual increase in the concentration of selenium (OP: 81.5 μg/L; 3rd month: 62.1 μg/L; 6th month: 63.0 μg/L; 12th month: 66.9 μg/L; 18th month: 66.8 μg/L; 24th month: 69.7 μg/L). The increase in selenium from 3 months after the operation achieved a significant level after 12 months (p = 0.043).
Calcium and Parathyroid Hormone In 62 of the 100 patients, PTH levels were preoperatively determined, and 22.6 % of the patients (14) had hyperparathyroidism. The average PTH levels (reference range: 10.0–69.0 ng/L) for patients with BMIs over 60 kg/m2 were 83.15 ng/L preoperatively, 73.30 ng/L after 6 months and 61.55 ng/L after 18 months ( Table 5 ; 6). Thirty-four patients (34.0 %) were supplemented with calcium carbonate and cholecalciferol, including 15 patients supplemented after RYGBP or DS. For calcium supplementation patients were supplemented with 500 mg calcium with 10 mg cholecalciferol four times daily. Twenty-four patients (24.0 %) were treated with separate or additional vitamin D supplementation due to high levels of PTH, including 9 patients treated preventively after a second operation.
Under supplementation, a rising concentration of PTH appeared 3 months after the operation. After 6 months, a significant decrease in the concentration of PTH was identified (p = 0.045). Course of PTH levels is shown in Table 6 .
Albumin SG did not significantly affect the patients' albumin levels (reference range: 34.0–48.0 g/L) during the follow-up period.
Vitamin B12 Overall, forty-two patients (42.0 %) received vitamin B12 supplementation. For vitamin B12 supplementation 1000 μg Vitamin B12 monthly was ordinated. 24 patients with SG as a standalone procedure (24.0 %) were supplemented within the first postoperative year and 18 patients after RYGBP or DS. ( Table 7 ). Under supplementation, the vitamin B12 levels achieved stable average values (reference range: 175–810 pmol/L) during the entire follow-up period.
The 75 patients after SG as a standalone procedure demonstrated stable and not significantly different vitamin B12 concentrations (OP: 285.6 pmol/L; 3rd month: 288.1 pmol/L; 6th month: 269.0 pmol/L; 12th month: 253.8 pmol/L; 18th month: 254.2 pmol/L; 24th month: 265.2 pmol/L) ( Table 7 ).
Folic Acid Regarding folic acid (reference range: 10.40–42.40 nmol/L), there was a significant decrease 3 months after the operation from 18.87 nmol/L to 15.29 nmol/L (p < 0.0005). 19 patients were supplemented. After RYGBP or DS 21 patient were given a supplementation according national and international guidelines. After the third month following the operation, an increasing concentration of folic acid was observed with a maximum average of 20.96 nmol/L after 24 months. Supplementation was performed with a combination of folic acid 0.5 mg and iron 40 mg daily.
BMC Surg. 2012;12(13) © 2012 BioMed Central, Ltd.
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