Selim Aksöyek

Intestinal ischemic preconditioning protects the intestine and reduces bacterial translocation.

Ischemic preconditioning (IPC) was first demonstrated in the heart, but this protective effect has been also recently described in the intestine. The aim of this study was to determine the effects of intestinal ischemic preconditioning on the morphology of intestine and bacterial translocation. Twenty-four male Wistar rats weighting 250 to 300 g were randomized into three groups. A control group of rats (n = 8) were subjected laparotomy. In an ischemic group (n = 8), laparotomy was performed and the superior mesenteric artery was occluded by an atraumatic clamp for 30 min. In the preconditioned group (n = 8), before the ischemia-reperfusion (I/R) period (as in ischemic group), rats were subjected to an initial 10 min of intestinal ischemia and 10 min of reperfusion. Twenty-four hours later, to evaluate whether the I/R induced intestinal injury and bacterial translocation (BT), tissue and blood samples were collected, and liver, spleen, and mesenteric lymph node specimens were obtained under sterile conditions for microbiological analysis. Samples of ileum were removed for both biochemical and histopathological evaluation. In the I/R group, the incidence of bacteria-isolated mesenteric lymph nodes, spleen, liver, and blood was significantly higher than other groups (P < 0.05). IPC prevented I/R-induced BT and it significantly reduced the I/R-induced intestinal injury (P < 0.05). Increased inducible nitric oxide (NO) synthase (iNOS) expression observed on the ileal specimens of the I/R group was found to be prevented by IPC. Our data suggest IPC as a key factor that reduces BT and iNOS activation in intestinal I/R. This is the first study showing that intestinal IPC blocks the cascade of events that causes BT and intestinal injury that may lead to sepsis.

Dexamethasone Down-Regulates Endothelial Expression of Intercellular Adhesion Molecule and Impairs the Healing of Bowel Anastomoses

OBJECTIVE To find out the role of endothelial expression of intercellular adhesion molecule-1 (ICAM-1) in the healing of intestinal anastomoses in rats, and to establish the effects of peroperative treatment with corticosteroids. DESIGN Experimental animal study. SETTING University hospital, Turkey. MATERIAL 78 Male Wistar rats. INTERVENTIONS Rats were divided into four groups: Group I, colonic anastomosis only (=18); Group II, colonic anastomosis plus caecal ligation and puncture (=18); Group III, colonic anastomosis plus dexamethasone (=18); and Group IV, colonic anastomosis, plus caecal ligation and puncture, plus dexamethasone (=18). Six animals served as the sham group. The animals underwent bowel transsection and primary anastomosis Infection was produced by caecal ligation and puncture Preoperatively, dexamethasone was given intramuscularly in a dose of 2 mg/kg/day. MAIN OUTCOME MEASURES After 1, 3 and 5 days, anastomotic healing and endothelial expression of ICAM-1 were measured microscopically. RESULTS Anastomotic healing was significantly impaired in dexamethasone-treated animals, and endothelial expression of ICAM-1 was reduced. Endothelial expression of ICAM-1 was no higher in the infected group than in controls. Maximum expression of ICAM-1 on endothelial cells was seen on the first day in each group, and declined on the following days, although the sebsequent reduction in expression was not significant. CONCLUSION Dexamethasone down-regulated expression of ICAM-1, which is important in migration of leucocytes from the circulation to the wound site, and significantly impaired the healing of intestinal anastomoses in rats.

Ischemic preconditioning reduces intestinal epithelial apoptosis in rats.

Recent experimental studies have described protective effect of ischemic preconditioning (IPC) on ischemia–reperfusion (I/R) injury of the intestine. We hypothesize that to reach a new point of view on the effect of IPC in intestinal barrier function, the relationship between I/R-induced mucosal injury and apoptosis must first be clarified. The present study was undertaken to investigate the role of IPC on intestinal apoptosis and probable contributions of bcl-2 expression to this process. We also investigated the effect of intestinal IPC on ileal malondyaldihyde levels. Forty-four male Wistar rats were randomized into four groups each consisting of 11 rats: sham-operated control, I/R group (30 min of superior mesenteric artery occlusion), IPC-I/R group (10 min of temporary artery occlusion prior before an ischemic insult of 30 min), and IPC alone group (10 min of preconditioning). Twenty-four hours later, ileum samples were obtained. Ileal malondyaldihyde levels were increased in the I/R group (31.9 ± 18.8 vs. 106.8 ± 39.8) but not in the IPC alone and IPC-I/R groups (38.1 ± 13.6 and 44.7 ± 12.7;P < 0.01). The number of apoptotic cells was significantly lower in IPC-I/R group than that of I/R group, and these findings were further supported by DNA laddering and M30 findings. Diminished bcl-2 expression observed in the ileal specimens of I/R group was prevented by IPC. Our results indicate that IPC may provide a protective effect on ileal epithelium and that this effect is probably the result of a significant increase in the expression of bcl-2 after the insult. The reversal of apoptosis by IPC might help preserving the vitality of intestinal structures that have a critical function, cessation of which often leads to multiorgan dysfunction syndrome.

Ileal atresia associated with a congenital vascular band anomaly: observations on pathogenesis

We report the case of a newborn, who developed intestinal obstruction soon after birth. Exploratory laparotomy revealed a congenital vascular band anomaly extending from the antimesenteric border of the terminal ileum to the gallbladder in association with ileal atresia. Surgical intervention was performed for correction of the disorder. A review of the embryology and congenital vascular bands is presented together with discussion as to possible etiopathogenesis leading to small bowel atresia.

Bilateral adrenal cystic neuroblastoma with massive hepatomegaly and intracystic hemorrhage

To The Editor: Cystic neuroblastoma (CNB) is a rare form of this tumor which is characterized by a large cystic lesion and microscopic cysts, and is frequently located in the adrenal gland. It has a little tendency to metastasis and it has an excellent prognosis if early diagnosis can be made [1–10]. Furthermore, bilateral adrenal CNB is an extremely unusual presentation of NB which may represent a second primary tumor or a contralateral metastasis [4]. Most of the patients with CNB are under 1 year of age. Moreover, massive intratumoral hemorrhage, hepatic metastases, and advanced clinical stage are also rare clinical findings. The differential diagnosis of a cystic suprarenal mass is difficult since it occurs not only in CNB, but also in adrenal hemorrhage, enteric cyst, extralobar sequestration, dilatation of upper-pole renal calyces, congenital adrenal cyst, cystic Wilms tumor, and adrenal abscess [2–4]. A 19-day-old girl, being born in another hospital, was admitted to our hospital with the symptoms of paleness, respiratory distress, and abdominal distention. Physical examination revealed tachycardia, tachypnea, hepatomegaly, and a large left-sided abdominal mass. Laboratory findings were as follows: hemoglobin 5.6 g/dl, serum lactate dehydrogenase 1,367 U/L, neuron specific enolase 56 ng/ml, ferritin 220 ng/ml, and urine vanillylmandelic acid 29.5 mg/day. Bone marrow infiltration with tumor cells (8%) was also found. Thorax CT revealed geometric shaped subpleural densities in the lungs consistent with atelectasis. Furthermore, CT scan of the abdomen showed bilateral adrenal cystic mass lesions with intracystic echogenities and fluid levels, suggesting intracystic hemorrhage. Besides hepatosplenomegaly, multiple hypodense lesions conforming to metastases in the liver were also observed (Fig. 1). Radionuclide bone scan was negative. Clinical diagnosis was congenital bilateral CNBwith liver metastases. However, lung metastases were also suspected. Since primary surgery could not be performed, chemotherapy was initiated. On the 8th day of chemotherapy, the patient died of extensive hepatic involvement, which caused respiratory and inferior vena cava compromise. Histopathologic examination revealed neuroblastoma cells at the wall of the almost entirely hemorrhagic cystic masses with favorable histology according to the Shimada classification, and lung, liver, and spleen involvement (Fig. 2). DNAcontent, N-myc expression, and allelic loss of chromosome 1p could not be obtained. Differentiation between adrenal hemorrhage and adrenal CNB is especially important because the treatment of hemorrhage is generally conservative. Although intratumoral hemorrhage is common in CNB, massive symptomatic hemorrhage is a rare finding [1,4,6]. To our knowledge, there have been only three reported cases with bilateral adrenalCNBwith intracystic hemorrhage [4,6,8]. In the newborn, reported by Lee et al. [4] the presence of the liver metastases made differential diagnosis easier as in our case. Since the other two reported cases with bilateral CNB which were diagnosed after the first month of life did not have liver involvement, the differential diagnosis of adrenal hemorrhagewas difficult [6,8]. MR imaging seems to be a good alternative radiological method in this differential diagnosis [6,9]. Most patientswithCNBare diagnosed in the early stage of disease with an excellent long-term prognosis, except patients with stage IV disease, hydrops, or massive hepatomegaly [2,3,10]. Only 9.7% of cases with CNB have metastatic disease at diagnosis [7]. When present, as in our case, the fetal liver is themost common site [5]. Two of three reported children with bilateral CNB had stage IVS, but one patient had stage IV disease. In children with CNB, less aggressive management may be warranted in the absence of stage IV disease. Some authors recommend that prenatally suspected non-metastatic CNB should undergo surgical intervention, unless tumor size decreases within about 1 month after birth [2,9]. While chemotherapy is necessary for advanced disease, as in our case, radiotherapy may be used in patients with unresectable or incompletely resected tumors [4]. One of two reported cases with bilateral CNB of stage IVS, to whom only surgical resection was performed, was lost to follow up,

Treatment of intestinal pseudo obstruction by segmental resection

Abstract. Intestinal pseudo-obstruction refractory to medical therapy is a debilitating problem for specialists dealing with gastrointestinal disorders. We report the case of a newborn who developed severe, recurrent symptoms of intestinal obstruction, due to visceral myopathy. The case was persistently intractable to medical management, leading to repeated laparotomies. Gastrointestinal lesions showed marked dilatation of the entire digestive tract, with enlarging to enormously distended segments at two areas. Resection of these segments improved bowel function, facilitating enteral nutrition. Long-term hyperalimentation and repetitive hospitalizations were also avoided with this procedure. These results suggest that segmental resections can save unnecessary intestinal resections in cases with extensive gastrointestinal involvement.

An unusual cause for massive upper gastrointestinal bleeding in children: Dieulafoy’s lesion

Dieulafoy’s lesion is a rare cause of severe upper gastrointestinal hemorrhage in children and predominantly occurs in the proximal stomach. We report a case of massive upper gastrointestinal bleeding in a 3-year-old boy that originated from a Dieulafoy’s lesion and was treated by epinephrine injection.

Comparison of electromagnetic field stimulation on the healing of small and large intestinal anastomoses

PURPOSE: Magnetic fields have been shown to affect biologic processes. Accordingly, an experimental study was designed to investigate the effect of electromagnetic field stimulation on intestinal healing and to compare small and large intestinal anastomoses. METHODS: An ileal or a colonic anastomosis was constructed in rats. Beginning the day after surgery, randomly assigned groups were exposed to sinusoidal electromagnetic field stimulation of 10.76-mT intensity and 50-Hz frequency, with 2-hour-on/10-hour-off cycles. After seven days, intestinal anastomoses were assessed for hydroxyproline content and breaking strength. Statistical comparison between each experimental and control group yielded significance (P<0.05) in all cases. RESULTS: Hydroxyproline content increased significantly in ileum from 1.650±0.11 (mean ± standard error of the mean) to 2.036±0.11µg/mg (P=0.0249) and in colon from 1.526±0.11 to 1.922±0.11µg/mg (P=0.0135). Breaking strength also increased significantly in ileum from 0.213±0.01 to 0.255±0.01 MPa (P=0.001) and in colon from 0.227±0.01 to 0.270±0.01 MPa (P=0.006). CONCLUSIONS: Electromagnetic field stimulation provided a significant gain in anastomotic healing in both small and large intestine. There were no apparent differences detected between the healing of small and large intestinal anastomoses except for slight differences in the time sequences of events and magnitude. The study demonstrated a significant increase in both biochemical and mechanical parameters. Additional investigations are needed to determine optimal conditions and promote selective biologic responses.

The Role of the Spleen on Colonic Anastomotic Healing

The role of the spleen on wound healing remains unclear. This study investigates the effect of splenectomy on the healing of colonic anastomoses. Twenty-six Wistar rats were assigned into four groups: sham, splenectomy, anastomoses, and splenectomy and anastomoses. The rats underwent a standardized left colonic resection and primary anastomoses, and/or splenectomy. Bursting pressure and hydroxyproline content were used to evaluate anastomotic healing, five days postoperatively. No differences were found in the bursting pressure and hydroxyproline content between the groups. The present results indicate that splenectomy has no negative effect on the healing of colonic anastomoses in rats.