Niels Komen

High tie versus low tie in rectal surgery: comparison of anastomotic perfusion

PurposeBoth “high tie” (HT) and “low tie” (LT) are well-known strategies in rectal surgery. The aim of this study was to compare colonic perfusion after HT to colonic perfusion after LT.MethodsPatients undergoing rectal resection for malignancy were included. Colonic perfusion was measured with laser Doppler flowmetry, immediately after laparotomy on the antimesenterial side of the colon segment that was to become the afferent loop (measurement A). This measurement was repeated after rectal resection (measurement B). The blood flow ratios (B/A) were compared between the HT group and the LT group.ResultsBlood flow was measured in 33 patients, 16 undergoing HT and 17 undergoing LT. Colonic blood flow slightly decreased in the HT group whereas the flow increased in the LT group. The blood flow ratio was significantly higher in the LT group (1.48 vs. 0.91; p = 0.04), independent of the blood pressure.ConclusionThis study shows the blood flow ratio to be higher in the LT group. This suggests that anastomoses may benefit from better perfusion when LT is performed.

Long-term and perioperative corticosteroids in anastomotic leakage: A prospective study of 259 left-sided colorectal anastomoses

OBJECTIVE To determine the risk factors for symptomatic anastomotic leakage (AL) after colorectal resection. DESIGN Review of records of patients who participated in the Analysis of Predictive Parameters for Evident Anastomotic Leakage study. SETTING Eight health centers. PATIENTS Two hundred fifty-nine patients who underwent left-sided colorectal anastomoses. INTERVENTION Corticosteroids taken as long-term medication for underlying disease or perioperatively for the prevention of postoperative pulmonary complications. MAIN OUTCOME MEASURES Prospective evaluations for risk factors for symptomatic AL. RESULTS In 23% of patients, a defunctioning stoma was constructed. The incidence of AL was 7.3%. The clinical course of patients with AL showed that in 21% of leaks, the drain indicated leakage; in the remaining patients, computed tomography or laparotomy resulted equally often in the detection of AL. In 50% of patients with AL, a Hartmann operation was needed. The incidence of AL was significantly higher in patients with pulmonary comorbidity (22.6% leakage), patients taking corticosteroids as longterm medication (50% leakage), and patients taking corticosteroids perioperatively (19% leakage). Perioperative corticosteroids were prescribed in 8% of patients for the prevention of postoperative pulmonary complications. CONCLUSIONS We found a significantly increased incidence of AL in patients treated with long-term corticosteroids and perioperative corticosteroids for pulmonary comorbidity. Therefore, we recommend that in this patient category, anastomoses should be protected by a diverting stoma or a Hartmann procedure should be considered to avoid AL. TRIAL REGISTRATION trialregister.nl Identifier: NTR1258

Calcium score: a new risk factor for colorectal anastomotic leakage.

BACKGROUND Anastomotic leakage (AL) is the most feared complication of colorectal surgery. Atherosclerosis is suggested to have a detrimental effect on anastomotic healing. This study aimed to analyze the calcium score, a measure for atherosclerosis, as a risk factor for AL. STUDY DESIGN The calcium scores of colorectal patients operated on in 2 Dutch university medical centers were determined using a computed tomography scan and calcium scoring software. The aorta, common iliac arteries, internal and external iliac arteries were studied. Additionally, patient- and operation-related factors were scored. RESULTS A total of 122 patients were included. In patients with AL, calcium scores were significantly higher in the left common iliac artery (561.4 vs 156.0, P = .028), right common iliac artery (542.0 vs 144.4, P = .041), both common iliac arteries together (1,103.3 vs 301.9, P = .046), and the left internal iliac artery (716.3 vs 35.3, P = .044). CONCLUSIONS Patients with higher calcium scores in the iliacal arteries have an increased leakage risk.

Prevention of leakage by sealing colon anastomosis: experimental study in a mouse model

BACKGROUND In colorectal surgery, anastomotic leakage (AL) is the most significant complication. Sealants applied around the colon anastomosis may help prevent AL by giving the anastomosis time to heal by mechanically supporting the anastomosis and preventing bacteria leaking into the peritoneal cavity. The aim of this study is to compare commercially available sealants on their efficacy of preventing leakage in a validated mouse model for AL. METHODS Six sealants (Evicel, Omnex, VascuSeal, PleuraSeal, BioGlue, and Colle Chirurgicale Cardial) were applied around an anastomosis constructed with five interrupted sutures in mice, and compared with a control group without sealant. Outcome measures were AL, anastomotic bursting pressure, and death. RESULTS In the control group there was a 40% death rate with a 50% rate of AL. None of the sealants were able to diminish the rate of AL. Furthermore, use of the majority of sealants resulted in failure to thrive, increased rates of ileus, and higher mortality rates. CONCLUSIONS If sealing of a colorectal anastomosis could achieve a reduction of incidence of clinical AL, this would be a promising tool for prevention of leakage in colorectal surgery. In this study, we found no evidence that sealants reduce leakage rates in a mouse model for AL. However, the negative results of this study make us emphasize the need of systemic research, investigating histologic tissue reaction of the bowel to different sealants, the capacity of sealants to form a watertight barrier, their time of degradation, and finally their results in large animal models for AL.

Postoperative adhesion prevention with a new barrier: an experimental study.

Introduction: Postoperative adhesion formation remains a major clinical problem. The aim of this study was to test the effect of a new hydrogel on adhesion formation in a rat model. Materials and Methods: A reproducible rat model was used to induce standardized adhesion formation in three experiments. In experiment 1, a cross-linked polyvinyl alcohol (PVA) and carboxymethylcellulose (CMC) hydrogel (PVA/CMC, A-Part®; B. Braun Aesculap, Germany) was tested in different dosages. In experiment 2, PVA/CMC gel was compared to icodextrin 4% (Adept®; Baxter USA). In both groups, animals were sacrificed after 2 weeks. In experiment 3, histological examination after 4 and 6 weeks was performed. The percentage of adhesions to the defect was measured and the density was determined according to the Zühlke scale. During histological examination of the abdominal wall, the formation of neoperitoneum and potential residues of the agents were assessed. Results: In experiment 1, a significant reduction in amount as well as density of the adhesions was visible with all dosages of PVA/CMC gel. In experiment 2, again quantity and density of the adhesions were diminished by PVA/CMC hydrogel compared to the control group. Icodextrin 4% showed no significant reduction in adhesion formation. In experiment 3, no residues of PVA/CMC gel or icodextrin 4% were found during histological examination after 4 and 6 weeks and neoperitoneum was present in all cases. Conclusion: PVA/CMC hydrogel appears to be a novel effective adhesion prevention agent. Together with an upcoming safety study, these data encourage to start clinical efficacy studies.

Detection of colon flora in peritoneal drain fluid after colorectal surgery: can RT-PCR play a role in diagnosing anastomotic leakage?

A semi-quantitative Real-Time PCR strategy was developed to identify potential indicator organisms for anastomotic leakage in peritoneal drainage fluid, Escherichia coli and Enterococcus faecalis. The analytical performance of the amplification method was validated with 10 culture-positive and 7 culture-negative peritoneal drain fluid samples, obtained from 9 different patients with a colorectal anastomosis. Real-Time PCR results were fully concordant with the microbiological culture results. However, among the culture-negative samples, four false-positive RT-PCR results were found. All false-positives originated from a single patient with a surgical site infection. This may indicate an elevated sensitivity of the RT-PCR method. The results showed that the semi-quantitative RT-PCR method has a clear potential to be useful as a powerful tool in early detection of anastomotic leakage.

Calcium scoring in unenhanced and enhanced CT data of the aorta-iliacal arteries: Impact of image acquisition, reconstruction, and analysis parameter settings

Background Several studies have been published on the matter of abdominal aortic and iliac calcifications and the association to clinical entities such as diabetes mellitus and renal failure. However, comparing of these studies is questionable since quantification methods for atherosclerosis differ. Purpose To evaluate the effect of image acquisition settings, reconstruction parameters, and analysis methods on calcium quantification in the abdominal aorta. Material and Methods Calcium scores were retrospectively determined on standardized abdominal CT scans of 15 patients. Two researchers obtained calcium scores with 10 different lower thresholds (LT) (130, 145, 160, 175, 200, 300, 400, 500, 600, 1000) in CT scans with and without contrast enhancement, with slice thicknesses (ST) varying between 2.0-5.0 mm for the non-contrast-enhanced series and between 1.0-5.0 mm for the contrast-enhanced series. In addition calcium scores obtained with two convolution kernels (B10f, B20f) were compared. Inter-observer variability was calculated. Results Calcium scoring at higher STs is overestimated compared to smaller STs and this effect was more pronounced with increasing calcium loads. Concerning the convolution kernel, scores obtained with kernel B10f were overestimated compared to kernel B20f. Increase of LT resulted in a decrease of the calcium score and scoring in contrast-enhanced series resulted in higher scores compared to non-contrast-enhanced series. These effects are more apparent in patients with higher calcium loads. Calcium scoring reproducibility with the reference standard is limited for the aorta-iliac trajectory, whereas scoring with the remaining settings is reproducible. Conclusion Scores obtained with different settings cannot be compared. The inter-observer reproducibility was limited using the reference standard and practical difficulties were substantial. Scoring with higher LT, ST, and contrast enhancement is faster and has less practical difficulties.

Oxygen-tension measurements - the first step towards prevention and early detection of anastomotic leakage

Many patients still die every year as a result of anastomotic leakage after surgery. The medical world needs an objective aid to detect leakage during surgery and during the critical recovery period. We propose a miniature measurement system to detect adequate tissue oxygenation pre-and postoperatively (continuously for 7 days) on the colon. The sensor chip should include an oxygen-saturation sensor, an oxygen-tension sensor, a carbon dioxide tension sensor and a temperature sensor. The work presented here focuses on the measurements done with the oxygen-tension and temperature sensors. In-vitro measurements were carried out to test the sensor system and initial in-vivo tests were performed on a rat kidney, during an ischemia-reperfusion experiment.

Tissue-Viability Monitoring Using an Oxygen-Tension Sensor

Many patients still die every year as a result of anastomotic leakage after surgery. An objective aid to monitor the anastomotic site pre- and postoperatively and detect leakage at an early stage is needed. We propose a miniature measurement system to detect adequate tissue oxygenation pre- and postoperatively (continuously for 7 days) on the colon. The complete sensor chip should include an oxygen-tension sensor (pO2), a carbon dioxide tension sensor (pCO2) and a temperature sensor. The work presented here focuses on the measurements done with the oxygen-tension and temperature sensors. In-vitro measurements have been initially performed to test the sensor system and in-vivo tests were carried out on the kidney and the intestines of male wistar rats. The results obtained so far have shown the suitability of this technique for clinical application, therefore sensor-system miniaturisation is presently underway.