Detection of inadequate anastomotic perfusion with handheld vital microscopy in two patients during colorectal surgery.

INTRODUCTION: Anastomotic leakage is one of the most feared complications after gastrointestinal surgery. Assessment of anastomotic viability during surgery remains challenging. Sufficient bowel tissue perfusion is a requisite for anastomotic healing. Handheld vital microscopy (HVM) is a non-invasive technique that can directly visualize the intestinal microcirculation during surgery. PRESENTATION OF TWO CASES: Two patients underwent elective laparoscopic colorectal surgery. During surgery HVM was used to assess bowel perfusion prior to creation of a primary anastomosis. Although the bowel macroscopically appeared to be well perfused, HVM showed a severely compromised microcirculation. The colon was re-internalized and during the following minutes cyanosis of the bowel occurred which was visually determined by the surgeon. After dissection towards cranially, a new site for the primary anastomosis was chosen. The postoperative period was uncomplicated. DISCUSSION: Sufficient bowel tissue perfusion is often mentioned as key in the pathophysiology of anastomotic leakage. HVM is a technique that could potentially aid surgeons in the assessment of microcirculatory perfusion of the bowel during surgery. CONCLUSION: We report two cases undergoing colorectal surgery in which HVM showed merit in detecting compromised bowel perfusion before creation of a primary anastomosis.

Association between serosal intestinal microcirculation and blood pressure during major abdominal surgery.

Background: In clinical practice, blood pressure is used as a resuscitation goal on a daily basis, with the aim of maintaining adequate perfusion and oxygen delivery to target organs. Compromised perfusion is often indicated as a key factor in the pathophysiology of anastomotic leakage. This study was aimed at assessing the extent to which the microcirculation of the bowel coheres with blood pressure during abdominal surgery. Methods: We performed a prospective and observational cohort study. In patients undergoing abdominal surgery, the serosal microcirculation of either the small intestine or the colon was visualized using handheld vital microscopy (HVM). From the acquired HVM image sequences, red blood cell velocity (RBCv) and total vessel density (TVD) were calculated using MicroTools and AVA software, respectively. The association between microcirculatory parameters and blood pressure was assessed using Pearson's correlation analysis. We considered a two-sided P-value of <0.050 to be significant. Results: In 28 patients undergoing abdominal surgery, a total of 76 HVM images were analyzed. The RBCv was 335 ± 96 µm/s and the TVD was 13.7 ± 3.4 mm/mm2. Mean arterial pressure (MAP) was 71 ± 12 mm Hg during microcirculatory imaging. MAP was not correlated with RBCv (Pearson's r = -0.049, P = 0.800) or TVD (Pearson's r = 0.310, P = 0.110). Conclusion: In 28 patients undergoing abdominal surgery, we found no association between serosal intestinal microcirculatory parameters and blood pressure.

Intestinal Mucosal and Serosal Microcirculation at the Planned Anastomosis during Abdominal Surgery.

INTRODUCTION: Intestinal blood flow is often named as a key factor in the pathophysiology of anastomotic leakage. The distribution between mucosal and serosal microperfusion during surgery remains to be elucidated. OBJECTIVE: The aim of this study was to assess if the mucosal microcirculation of the intestine is more vulnerable to a surgical hit than the serosal microcirculation during surgery. METHODS: In an observational cohort study (n = 9 patients), the microcirculation of the bowel serosa and mucosa was visualized with incident dark-field imaging during surgery. At the planned anastomosis, the following microcirculatory parameters were determined: microvascular flow index (MFI), percentage of perfused vessels (PPV), perfused vessel density (PVD), and total vessel density (TVD). Data are presented as median (interquartile range [IQR]). RESULTS: Perfusion parameters and vessel density were significantly higher for the mucosa than the serosal microcirculation at the planned site for anastomosis or stoma. Mucosal MFI was 3.00 (IQR 3.00-3.00) compared to a serosal MFI of 2.75 (IQR 2.21-2.94), p = 0.03. The PPV was 99% (IQR 98-100) versus 92% (IQR 66-94), p = 0.01. The TVD was 16.77 mm/mm2 (IQR 13.04-18.01) versus 10.42 mm/mm2 (IQR 9.36-11.81), p = 0.01, and the PVD was 15.44 mm/mm2 (IQR 13.04-17.78) versus 9.02 mm/mm2 (IQR 6.43-9.43), p = 0.01. CONCLUSIONS: The mucosal microcirculation was preserved, while lower perfusion of the serosa was found at the planned anastomosis or stoma during surgery. Further research is needed to link our observations to the clinically relevant endpoint of anastomotic leakage.

Local application of gentamicin-containing collagen implant in the prophylaxis of surgical site infection following gastrointestinal surgery.

BACKGROUND: Gastrointestinal surgery is associated with one of the highest rates of SSI due to the nature of the surgery and to the added complication of operating on patients with significant co-morbidities. This high rate of SSI may negatively impact wound healing, patient recovery time, length of hospital stay and associated healthcare costs. This article provides an overview of the efficacy and safety of prophylactic application of resorbable gentamicin-containing collagen implants (GCCI) in the prevention of SSI following GI surgical procedures. METHOD: Thirteen publications were identified using the PubMed online database and search terms 'gentamicin collagen implant' plus 'surgical site infection', 'wound infection' and 'gastrointestinal surgery'. RESULTS: Eleven out of 13 studies have demonstrated that prophylactic use of GCCI can reduce the wound infection rate in high-risk GI surgical procedures (e.g. abdominoperineal resection [APR]) and improve wound healing after pilonidal sinus excision. GCCI may also have a role to play in preventing anastomotic leakage following mesorectal excision for rectal carcinoma. It is recommended that GCCI are used dry in line with the manufacturer's recommendations. CONCLUSION: This review demonstrates that GCCI can significantly reduce surgical site infection following GI surgery including pilonidal sinus excision and high-risk procedures such as APR.

Effect of remote ischemic conditioning on atrial fibrillation and outcome after coronary artery bypass grafting (RICO-trial).

BACKGROUND: Pre- and postconditioning describe mechanisms whereby short ischemic periods protect an organ against a longer period of ischemia. Interestingly, short ischemic periods of a limb, in itself harmless, may increase the ischemia tolerance of remote organs, e.g. the heart (remote conditioning, RC). Although several studies have shown reduced biomarker release by RC, a reduction of complications and improvement of patient outcome still has to be demonstrated. Atrial fibrillation (AF) is one of the most common complications after coronary artery bypass graft surgery (CABG), affecting 27-46% of patients. It is associated with increased mortality, adverse cardiovascular events, and prolonged in-hospital stay. We hypothesize that remote ischemic pre- and/or post-conditioning reduce the incidence of AF following CABG, and improve patient outcome. METHODS/DESIGN: This study is a randomized, controlled, patient and investigator blinded multicenter trial. Elective CABG patients are randomized to one of the following four groups: 1) control, 2) remote ischemic preconditioning, 3) remote ischemic postconditioning, or 4) remote ischemic pre- and postconditioning. Remote conditioning is applied at the arm by 3 cycles of 5 minutes of ischemia and reperfusion. Primary endpoint is the incidence AF in the first 72 hours after surgery, detected using a Holter-monitor. Secondary endpoints include length-of-stay on the intensive care unit and in-hospital, and the occurrence of major adverse cardiovascular events at 30 days, 3 months and 1 year.Based on an expected incidence in the control group of 27%, 195 patients per group are needed to detect with 80% power a reduction by 45% following either pre- or postconditioning, while allowing for a 10% dropout and at an alpha of 0.05. With the combined intervention expected to be stronger, we need 75 patients in this group to detect a reduction in incidence of AF of 60%. DISCUSSION: The RICO-trial (the effect of Remote Ischemic Conditioning on atrial fibrillation and Outcome) is a randomized controlled multicenter trial, designed to investigate whether remote ischemic pre- and/or post-conditioning of the arm reduce the incidence of AF following CABG surgery. TRIAL REGISTRATION: ClinicalTrials.gov under NCT01107184.

Desktop simulator: key to universal training?

BACKGROUND: Training of skills in simulators is preferred over learning on patients so as to avoid undue injury to patients and to allow more efficient use of resources. Most simulators are costly and require a dedicated space. The aim of this study was to evaluate a simple desktop simulator, the Mirror Trainer. METHODS: Thirty medical students were randomly assigned to three groups. One group was taught laparoscopic suturing in the Mirror Trainer, the second group used a pelvic training box, while the third group served as a control group and did not receive any training. All suture attempts during training were recorded on video. A blinded, independent investigator analyzed the videos. At the completion of training, the suturing skills of each participant were evaluated in an animal model. RESULTS: Training with the Mirror Trainer required less time than with the pelvic trainer (p < 0.001). Compared with the control group, the Mirror Trainer group and the pelvic trainer group were significantly faster at creating three knots in the pig (p = 0.001 and p = 0.004, respectively). Both training groups performed equally well on the animal model (p = 0.99). CONCLUSION: The Mirror Trainer and the pelvic trainer are equally effective in teaching laparoscopic suturing skills but training with the Mirror Trainer requires less time, can be done on any desktop, and is less costly.