Small Intestinal Anastomosis: Comparitive Study Of Mechanical Healing After Apposition And Inverting Suturing

Objective:To observe the stomal mechanical healing process after small intestinal opposition suturing and to investigate the feasibility of opposition suturing in gastrointestinal anastomosis.Method:Chinese adult rabbits were randomly divided into A, B Group. In Group A, small intestine abscise at 20cm and 40 cm from duodenojejunal ligament and all rabbits were performed apposition and inverting suturing at 20cm and 40cm respectively. Group B stomal anastomosis designed same as of the group A but suturing method sequence was reversed.1. Ganstrointestinal tract (GIT) CT scan performed on all rabbits at 7d, 14d and 28d postoperatively.2. In vivo stomal macroscopic observation made at postoperative 24h,3d,7d,14d and 28d.3. Anastomotic blasting pressure (ABP) measured at postoperative 24h,3d,7d,14d and 28d.4. Anastomotic Tensile strength measured at postoperative 24h,3d,7d,14d and 28d.Results:1. CT scan indication: At 7d and 14d anastomotic inner diameter of inverted sutured was narrower than that of apposition sutured.2. The naked eye in vivo observation revealed anastomotic bleeding, dehiscence and leakage in both groups. No intestinal obstruction and intra-peritoneal abscess was found. In Apposition suture anastomosis tissue layers were closely attached, neat, lightly inflamed with good primary wound healing.3. Postoperative burst pressure was measured at 24hour,3days,7days,14days,28days. Apposition suture anastomotic burst pressure were 62±2.08,53±3.33,110±9.60,176±8.67,231±14.59mmHg respectively and Inverting suture anastomosis were 79±5.65,38±6.03,84±6.17,153±7.00,188±17.91mmHg respectively .There was significant statistical difference (P<0.01) between the inverting suture group and apposition suture group. Anastomotic blasting pressure of apposition suture was lower than Inverting suture at 24h but was higher on all intervals (3d, 7d, 14d, 28d) than that of inverting sutured.4. Anastomotic tensile strength measured at postoperative 24h,3d,7d,14d and 28d and measured seromuscular tensile strength of apposition suture values were 353±29.0g,188±34.9g,278±23.7g,323±18.1 g,545±15.5g respectively . Submucosa tensile strength measured values were 435±40.7g,208±22.0g,302±19.7 g,362±22.5 g,590±13.2 g respectively . In inverting sutured anastomosis tensile strength valuies were measured at 24h,3d,7d,14d and 28d postoperative; the seromuscular layer tensile strength values were 373±27.1 g,135±21.5 g,204±13.8g,297±18.7g,536±14.0 g and submucosal tensile strength values were 460±30.0g,181±15.1g,260±51.7g,322±13.5g,585±10.7g respectively .Tensile strength values of apposition sutured and inverting sutured group were compared. There existed significant statistical differences (P<0.05). Anastomotic tensile strength of apposition suture was lower than Inverting suture at 24h but was higher on all intervals (3d, 7d, 14d, 28d) than that of inverting sutured.Conclusion:1. Multi slice spiral CT revealed that at postoperative 7days and 14days anastomotic diameter of Inverting sutured group was narrower than that of apposition sutured group.2. Apposition sutured group exhibit primary stomal healing while inverting sutured group exhibit secondary stomal healing.3. Anastomotic blasting pressure and tensile strength of apposition sutured group was lower than Inverting sutured group at 24h but was higher on all intervals (3d,7d,14d,28d) than that of inverting sutured group.