Dissection Phase Research Articles

Strategies and outcome in small for size grafts in living donor liver transplantation

Introduction: Graft recipient weight ratio (GRWR) of ≥0.8 is considered gold standard to avoid small for size syndrome (SFSS) in living donor liver transplantation (LDLT). However, lower GRWR (<0.8) have been shown to give equally good outcomes with portal inflow modulation (IM). Aim: To evaluate outcomes of LDLT with small for size grafts. Methods: Among 1264 adult LDLT from 2012 to September 2017, 274 were with GRWR <0.8. Portal pressure (PP) was measured in the dissection, post-reperfusion phases.IM was performed in 121 (44.1%) patients according to GRWR-based protocol Result: Mean age was 49.30 year. The median CTP and MELD scores were 10 (IQR: 8–11) and 14 (IQR: 10–18) respectively. The lowest GRWR was 0.55. 53 recipients had GRWR between 0.55–0.69 (HPCS-52 and HPCS+SAL-1) and 221 had GRWR between 0.70-0.79 (HPCS 54, SAL = 12, Coronary caval shunt-1, HPCS+SAL-1) and 990 had ≥0.80. The median PP in dissection phase and post reperfusion were 27 (IQR: 22-30) and 15 (IQR: 13-22) mm Hg respectively. 12 (4.37%) developed SFSS and six of them died due to SFSS. One year survival of patients across different GRWR were comparable (83.01% vs 82.8% vs 87.7%). Two patients needed partial shunt closure at 1 and 4 weeks; the latter died of sepsis. No other shunt related complications were encountered. Conclusion: The decision of inflow modulation based on GRWR and PP result in acceptable recipient outcomes in small for size grafts and overall patient survival is comparable to grafts with GRWR ≥0.8.

Correlation Between Blood Transfusion and Blood Glucose Levels in Adult Living Donor Liver Transplantation

BackgroundTo evaluate the effect of dextrose contained in banked blood products on the changes of blood glucose levels in adult living donor liver transplantation patients retrospectively. MethodsFour hundred seventy-seven patients were divided into a non–blood transfusion (BT) group (G1) and a BT group (G2). The changes in blood glucose levels during the operation were compared using a Mann-Whitney U test, and a P value less than .05 was regarded as significant. ResultsNo significant changes were detected in blood glucose levels after anesthesia, during dissection phase, in the anhepatic phase, or after reperfusion between the groups. Estimated blood loss for G1 (n = 89) and G2 (n = 388) were 718 ± 514 and 5804 ± 877 mL respectively, G1 had no blood transfusion but G2 had received 4350 ± 6230 mL leukocyte-poor red blood cell transfusion, the pre- and end operation hemoglobin for G1 and G2 were 13.2 ± 2.0, 10.2 ± 1.9 and 10.1 ± 1.6, 10.2 ± 1.9 mg/dL respectively, indicating that they were not under or over transfused. ConclusionWhen banked blood products are used to replace ongoing blood loss, the dextrose contained in citrate-phosphate-dextrose-adenine seems to have no effect on the changes in the blood glucose levels of the recipients.

Liver transplantation for acute liver failure due to hepatitis E in a pregnant patient.

Liver transplantation for acute liver failure due to hepatitis E in a pregnant patient.

MP59-18 IMPACT OF MAYO ADHESIVE PROBABILITY SCORE ON THE COMPLEXITY OF ROBOT-ASSISTED PARTIAL NEPHRECTOMY.

You have accessJournal of UrologyKidney Cancer: Localized: Surgical Therapy IV1 Apr 2017MP59-18 IMPACT OF MAYO ADHESIVE PROBABILITY SCORE ON THE COMPLEXITY OF ROBOT-ASSISTED PARTIAL NEPHRECTOMY. Ryo Ishiyama, Tsunenori Kondo, Toshio Takagi, Junpei Iizuka, Hirohito Kobayashi, Kenji Omae, Norihiro Fukuda, Hiroki Ishihara, and Kazunari Tanabe Ryo IshiyamaRyo Ishiyama More articles by this author , Tsunenori KondoTsunenori Kondo More articles by this author , Toshio TakagiToshio Takagi More articles by this author , Junpei IizukaJunpei Iizuka More articles by this author , Hirohito KobayashiHirohito Kobayashi More articles by this author , Kenji OmaeKenji Omae More articles by this author , Norihiro FukudaNorihiro Fukuda More articles by this author , Hiroki IshiharaHiroki Ishihara More articles by this author , and Kazunari TanabeKazunari Tanabe More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2017.02.1834AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Adhesive perinephric fat (APF) increases the complexity of robot-assisted partial nephrectomy (RAPN). The Mayo adhesive probability (MAP) score is an index for quantifying APF and predicting prolonged operation time or increased surgical complication rate. However, the part of the operation influenced by increased MAP score remains unclear. METHODS The study subjects were 311 patients who underwent RAPN between January 2013 and June 2016 in our institute. MAP score was calculated to quantify APF. The perinephric fat thickness and stranding were used to calculate the MAP score. Operation time was divided into a dissection phase (from robotic manipulation to hilar clamping) and resection phase (from hilar clamping to robotic surgery completion). RESULTS The patients' mean age, body mass index (BMI), total operation time, console time, dissection phase time, and resection phase time were 60±13 years, 23.5±3.5 kg/m2, 180.8±40.7 minutes, 132.6±36.5 minutes, 84.9±27.6 minutes, and 47.6±18.3 minutes, respectively. The MAP score was 0 in 98 patients (32%), 1 in 86 (28%), 2 in 21 (7%), 3 in 48 (15%), 4 in 44 (14%), and 5 in 14 (4%). The dissection and resection phase times significantly increased as the MAP scores increased (Figure 1). The dissection phase times were 71.2, 79.1, 88.9, 97.0, 99.7, and 118.8 minutes as the MAP score increased by 1 point from 0 to 5 (p<0.001). The influence of MAP score was more remarkable to the prolongation of the dissection phase than to that of the resection phase. In the patients with MAP scores of =3, the dissection phase time was not significantly influenced by the learning curve (100.8±25.2, 103.7±29.4, and 98.2±31.4 minutes in 1st-100th, 101st-200th, and 201st-311th, respectively). We further examined the factors that influenced the dissection phase time of 100 minutes by using the logistic regression model. In the multivariate analysis, left side, early surgical experience (first 100 cases), the number of the renal arteries to be clamped and MAP score (=3) were the independent factors of prolonged dissection phase. CONCLUSIONS MAP score is an independent predictive factor of prolonged RAPN dissection phase. The complexity of RAPN in the patients with high MAP scores was still high even for experienced surgeons. © 2017FiguresReferencesRelatedDetails Volume 197Issue 4SApril 2017Page: e788 Advertisement Copyright & Permissions© 2017MetricsAuthor Information Ryo Ishiyama More articles by this author Tsunenori Kondo More articles by this author Toshio Takagi More articles by this author Junpei Iizuka More articles by this author Hirohito Kobayashi More articles by this author Kenji Omae More articles by this author Norihiro Fukuda More articles by this author Hiroki Ishihara More articles by this author Kazunari Tanabe More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Evaluation of New Calibrated Pulse-Wave Analysis (VolumeViewTM/EV1000TM) for Cardiac Output Monitoring Undergoing Living Donor Liver Transplantation.

BackgroundIntrapulmonary thermodilution technique using a pulmonary artery catheter is widely used for measuring cardiac output (CO) in patients undergoing liver transplantation. However, its invasiveness and associated complications have led to an interest in less invasive modalities. Thus, we aimed to evaluate whether the new calibrated pulse-wave analysis method monitoring (VolumeViewTM/EV1000TM) is interchangeable with intrapulmonary thermodilution technique.MethodsTwenty-eight patients undergoing living donor liver transplantation were enrolled in this prospective observational study. COs were recorded automatically by the two devices and compared simultaneously at 10-minute intervals. The agreement of absolute CO values and the tracking ability of CO changes trends were compared. A Bland-Altman analysis with percentage errors and concordance rate for trend analysis using both a 4-quadrant plot and a polar plot were performed on the data.ResultsA total of 375 paired datasets from 25 patients were included in analysis. COs measured by intrapulmonary thermodilution ranged from 3.8–13.7 L/min. The mean CO difference between the two techniques was 0.57 L/min, and the 95% limits of agreement were -0.98 L/min to 2.12 L/min with a percentage error of 42.3%. The percentage errors in the dissection, anhepatic, and reperfusion phase were 30.5%, 31.7%, and 27.4%, respectively. The concordance rate between the two techniques was 78.4%.ConclusionThe calibrated pulse-wave analysis and intrapulmonary thermodilution failed to show acceptable interchangeability in terms of both estimating CO and tracking CO changes during living donor liver transplantation.

Pilot study of closed-loop anaesthesia for liver transplantation

BackgroundAutomated titration of propofol and remifentanil guided by the bispectral index (BIS) has been used for numerous surgical procedures. Orthotopic liver transplantation (OLT) uniquely combines major changes in circulating volume, an anhepatic phase, and ischaemia–reperfusion syndrome. We assessed the behaviour of this automated controller during OLT. MethodsAdult patients undergoing OLT were included in this pilot study. Consumption of propofol and remifentanil was calculated for each surgery period (dissection, anhepatic, and liver reperfusion phases). Arterial blood samples were collected at several time points to allow comparison of actual with calculated propofol and remifentanil concentrations. Data are presented as median [25th and 75th percentiles] or percentage (95% confidence interval). ResultsThirteen patients were studied. System performance, defined as the percentage of time with BIS in the range 40-60, was 88% (86-94) of the total duration of anaesthesia. Propofol requirement was decreased during the anhepatic phase compared with the dissection phase (2.9 [1.9-5.0] mg kg−1 h−1 and 4.6 [3.5-8.1] mg kg−1 h−1; P<0.03) while remifentanil consumption was unchanged (0.11 [0.09-0.19] µg kg- 1 min−1). Bland-Altman analysis showed a weak concordance for propofol (bias of 0.7 µg ml−1 and limits of agreement of −2.2 to +3.7 µg ml−1) and remifentanil (bias of 1.3 ng ml−1 and limits of agreement −4.3 to +6.8 ng ml−1). No adverse events were reported during anaesthesia. ConclusionsThis pilot study indicates that automated titration of propofol and remifentanil guided by the BIS is feasible during OLT.

Evaluation of pleth variability index as a predictor of fluid responsiveness during orthotopic liver transplantation

Fluid management is challenging and still remains controversial in orthotopic liver transplantation (OLT). The pleth variability index (PVI) has been shown to be a reliable predictor of fluid responsiveness of perioperative and critically ill patients; however, it has not been evaluated in OLT. This study was designed to examine whether the PVI can reliably predict fluid responsiveness in OLT and to compare PVI with other hemodynamic indexes that are measured using the PiCCO2 monitoring system. Twenty-five patients were enrolled in this study. Each patient was monitored using the noninvasive Masimo and PiCCO2 monitoring system. PVI was obtained with a Masimo pulse oximeter. Cardiac index was obtained using a transpulmonary thermodilution technique (CITPTD). Stroke volume variation (SVV), pulse pressure variation, and systemic vascular resistance index were measured using the PiCCO2 system. Fluid loading (10 mL/kg colloid) was performed at two different phases during the operation, and fluid responsiveness was defined as an increase in CITPTD ≥ 15%. During the dissection phase and the anhepatic phase, respectively, 14 patients (56%) and 18 patients (75%) were classified as responders. There were no differences between the baseline values of the PVI of responders and nonresponders. Area under the curve for PVI was 0.56 (sensitivity 35%, specificity 90%, p = 0.58) at dissection phase, and was 0.55 (sensitivity 55%, specificity 66%, p = 0.58) at anhepatic phase. Of the parameters, a higher area under the curve value was found for SVV. We conclude that PVI was unable to predict fluid responsiveness with sufficient accuracy in patients undergoing OLT, but the SVV parameter was reliable.

Evaluation of cardiac output by bioreactance technique in patients undergoing liver transplantation

BackgroundThis study compared the cardiac output (CO) obtained from PiCCO with that obtained from the noninvasive NICOM method. MethodsTwenty-one cirrhotic patients receiving liver transplantation were enrolled. During the operation, their CO was measured by the PiCCO system via the thermodilution method as the standard and by the NICOM method. Two parameters including cardiac index (CI) and stroke volume index (SVI) were collected simultaneously at three phases during the surgery including the dissection phase (T1), the anhepatic phase (T2), and the reperfusion phase (T3). Correlation, Bland and Altman methods, and linear mixed model were used to evaluate the monitoring ability of both systems. ResultsPoor correlation was noted between the data measured by NICOM and PiCCO; the correlation coefficients for CI and SVI measured between the two systems were 0.32 and 0.39, respectively. Bland and Altman analysis showed the percentage error of CI as 63.7%, and that of SVI as 66.6% for NICOM compared to PiCCO. Using the linear mixed model, the CI and SVI measured using NICOM were significantly higher than those using PiCCO (estimated regression coefficient 0.92 and 10.77, both p < 0.001). Mixed model analysis showed no differences between the trends of CI and SVI measured by the two methods. ConclusionsNICOM provided a comparable CI and SVI trend when compared to the gold standard PiCCO, but it raises concerns as an effective CO monitor because of its tendency to overestimate CI and SVI especially during the state of high cardiac output.

Coagulopathy and transfusion therapy in pediatric liver transplantation.

Bleeding and coagulopathy are critical issues complicating pediatric liver transplantation and contributing to morbidity and mortality in the cirrhotic child. The complexity of coagulopathy in the pediatric patient is illustrated by the interaction between three basic models. The first model, "developmental hemostasis", demonstrates how a different balance between pro- and anticoagulation factors leads to a normal hemostatic capacity in the pediatric patient at various ages. The second, the "cell based model of coagulation", takes into account the interaction between plasma proteins and cells. In the last, the concept of "rebalanced coagulation" highlights how the reduction of both pro- and anticoagulation factors leads to a normal, although unstable, coagulation profile. This new concept has led to the development of novel techniques used to analyze the coagulation capacity of whole blood for all patients. For example, viscoelastic methodologies are increasingly used on adult patients to test hemostatic capacity and to guide transfusion protocols. However, results are often confounding or have limited impact on morbidity and mortality. Moreover, data from pediatric patients remain inadequate. In addition, several interventions have been proposed to limit blood loss during transplantation, including the use of antifibrinolytic drugs and surgical techniques, such as the piggyback and lowering the central venous pressure during the hepatic dissection phase. The rationale for the use of these interventions is quite solid and has led to their incorporation into clinical practice; yet few of them have been rigorously tested in adults, let alone in children. Finally, the postoperative period in pediatric cohorts of patients has been characterized by an enhanced risk of hepatic vessel thrombosis. Thrombosis in fact remains the primary cause of early graft failure and re-transplantation within the first 30 d following surgery, and it occurs despite prolongation of standard coagulation assays. Data, however, are currently lacking regarding the use of anti-aggregation/anticoagulation therapies and how to best monitor for thrombosis in the early postoperative period in pediatric patients. Therefore, further studies are necessary to elucidate the interaction between the development of the coagulation system and cirrhosis in children. Moreover, strategies to optimize blood transfusion and anticoagulation must be tested specifically in pediatric patients. In conclusion, data from the adult world can be translated with difficulty into the pediatric field as indication for transplantation, baseline pathologies and levels of pro- and anticoagulation factors are not comparable between the two populations.

Single stage robotic total mesorectal excision-a stepwise approach.

The totally robotic procedure was traditionally described as a two-stage technique or a three-stage technique. The number of stages corresponds to the number of movements of the robotic cart. In this video article, we develop a stepwise approach video of robotic total mesorectal excision (TME) for mid rectal cancer (the surgery was performed by SHK) using a da Vinci® Si HD Surgical System (Intuitive Surgical, Sunnyvale, CA, USA) at Korea University Anam Hospital, Seoul. After the induction of general anesthesia, the patient is placed in a modified lithotomy position. Six ports are used, including one 12-mm camera port, four 8-mm robotic working ports, and one 5-mm port for the assistant. The patient is tilted to the right side and placed in the Trendelenburg position. The small-bowel loops retracted out from the pelvic cavity to the right upper quadrant (RUQ) to expose the inferior mesenteric artery (IMA). The surgery is divided into three phases: (I) abdominal phase: vascular ligation, and sigmoid colon to splenic flexure mobilization; (II) pelvic dissection phase; and (III) rectal reconstruction phase. Mesorectal clearing was done at the level of rectal transection line (1-2 cm from distal tumor margin), then the rectum was transected with robotic stapler. Once this step is finished, the robotic arms are undocked and the cart is moved away from the patient. The remaining steps are performed in a conventional laparoscopic method. Robotic TME was performed in a 56-year-old man with an endoscopically define rectal mass. The lesion was moderately differentiated adenocarcinoma, 8 cm from the anal verge (AV). The rectal mass was managed with single stage robotic TME. The operative time was 160 minutes and the patient was discharge on post operative day 10. Final pathology revealed moderately differentiated adenocarcinoma. Single stage robotic TME was efficient and feasible technique for mid rectal cancer resection.

Liver Transplantation: Intraoperative Transesophageal Echocardiography Findings and Relationship to Major Postoperative Adverse Cardiac Events.

The primary aim of the study was to describe the most common intraoperative transesophageal echocardiography (TEE) findings during the 3 separate phases of orthotopic liver transplantation (OLT). The secondary aim of the study was to determine if the abnormal TEE findings were associated with major postoperative adverse cardiac events (MACE) and thus may be amenable to future management strategies. Data were collected retrospectively from the electronic medical record and institutional echocardiography database. Single university hospital. A total of 100 patients undergoing OLT via total cavaplasty technique. Intraoperative TEE was performed in all 3 phases of OLT. TEE findings of 100 patients who had TEE during OLT during the dissection, anhepatic, and reperfusion phases of transplantation were recorded after blind review. Findings then were analyzed to see if those findings were predictive of postoperative MACE. Intraoperative TEE findings varied among the different phases of OLT. Common TEE findings at reperfusion were microemboli (n = 40, 40%), isolated right ventricular dysfunction (n = 22, 22%), and intracardiac thromboemboli (n = 20, 20%). Intraoperative echocardiography findings during liver transplantation varied during each phase of transplantation. The presence of intracardiac thromboemboli or biventricular dysfunction on intraoperative echocardiography was predictive of short- and long-term major postoperative adverse cardiac events.

Bioreactance Is Not Interchangeable with Thermodilution for Measuring Cardiac Output during Adult Liver Transplantation.

BackgroundThermodilution technique using a pulmonary artery catheter is widely used for the assessment of cardiac output (CO) in patients undergoing liver transplantation. However, the unclearness of the risk-benefit ratio of this method has led to an interest in less invasive modalities. Thus, we evaluated whether noninvasive bioreactance CO monitoring is interchangeable with thermodilution technique.MethodsNineteen recipients undergoing adult-to-adult living donor liver transplantation were enrolled in this prospective observational study. COs were recorded automatically by the two devices and compared simultaneously at 3-minute intervals. The Bland–Altman plot was used to evaluate the agreement between bioreactance and thermodilution. Clinically acceptable agreement was defined as a percentage error of limits of agreement <30%. The four quadrant plot was used to evaluate concordance between bioreactance and thermodilution. Clinically acceptable concordance was defined as a concordance rate >92%.ResultsA total of 2640 datasets were collected. The mean CO difference between the two techniques was 0.9 l/min, and the 95% limits of agreement were -3.5 l/min and 5.4 l/min with a percentage error of 53.9%. The percentage errors in the dissection, anhepatic, and reperfusion phase were 50.6%, 56.1%, and 53.5%, respectively. The concordance rate between the two techniques was 54.8%.ConclusionBioreactance and thermodilution failed to show acceptable interchangeability in terms of both estimating CO and tracking CO changes in patients undergoing liver transplantation. Thus, the use of bioreactance as an alternative CO monitoring to thermodilution, in spite of its noninvasiveness, would be hard to recommend in these surgical patients.

Abstract 502: Smokers Have Significantly Increased Rates of Intraoperative Microembolization Detected on Transcranial Doppler with Carotid Angioplasty/Stenting Compared to Endarterectomy Procedure in Preliminary Study

Background: The benefits of revascularization must be balanced against the risks of peri/post-operative cerebrovascular events in determining the management of carotid stenosis. Higher rates of intra-operative microembolization during elective carotid revascularization are associated with increased risks of clinically detectable cerebrovascular accidents, and the identification of specific patient demographics that predispose to vulnerable plaque formation can be useful in guiding intervention and decreasing embolic potential during procedures. Methods: 150 patients (symptomatic, stenosis&gt;50%; asymptomatic, stenosis&gt;70%) undergoing either CAS or CEA will be enrolled. A pre-operative Mini-mental Status Exam, carotid MRI, and cerebral diffusion-weighted MRI are obtained one week prior to intervention. All MRI are performed with 3T MR system, carotid plaque are classified according to AHA criteria. Intraoperatively, transcranial Doppler is performed to monitor for microembolic signals (MES), detected as high-intensity unidirectional transient signals. Plaque specimen and filter debris are analyzed histologically for high-risk characteristics and correlated with MRI. A post-operative DW-MRI and MMSE are performed within 72 hours to examine for microinfarcts and changes in neurocognitive function. Demographic analysis for cardiovascular risk factors, current and former smokers, was performed retrospectively. Results: Preliminary results with 33 patients demonstrate an average of 46 total MES generated during carotid angioplasty/stenting in 4 nonsmokers, compared to 19.9 total MES in 9 nonsmoking patients undergoing endarterectomy (p = 0.091). In the smoker population, an average of 63.4 total MES was generated in 13 patients undergoing CAS compared to 21 total MES in 7 patients undergoing CEA (p = 0.024). Procedural phases with the highest production of microemboli include dissection phase during CEA (35.5% of total MES) and filter placement in CAS (22.2% of total MES). Conclusions: Preliminary results suggest significantly increased microembolic potential and risk of clinically detectable CVA with carotid angioplasty/stenting compared to endarterectomy in smokers.

Use of intravenous methylene blue for catecholamine‐refractory vasoplegia during liver transplantation

SummaryWe report a patient with catecholamine‐refractory vasoplegia who was successfully managed with intravenous methylene blue. A 22‐yr‐old female with primary hyperoxaluria underwent orthotopic liver transplantation. During the early dissection phase she remained haemodynamically stable. Towards the latter part of the dissection phase, her blood pressure decreased to around 60/25 mmHg and she became unresponsive to fluid therapy, conventional vasopressors and inotropes.However, she demonstrated a remarkable response to a bolus of intravenous methylene blue, 2 mg.kg‐1 administered over 20 min. She remained haemodynamically stable for the remainder of the procedure and was transferred to ICU with an intravenous methylene blue infusion running and minimal vasopressor requirements.Intravenous methylene blue seems a promising rescue treatment for refractory vasoplegia during liver transplantation. It competitively inhibits guanylase cyclase, thus responsiveness of cyclic guanosine monophosphate (cGMP)‐mediated vasodilators such as nitric oxide (NO) is reduced, leading to improved vasomotor tone.

Comparison of two fluid warming devices for maintaining body core temperature during living donor liver transplantation: Level 1 H-1000 vs. Fluid Management System 2000.

BackgroundRapid fluid warming has been a cardinal measure to maintain normothermia during fluid resuscitation of hypovolemic patients. A previous laboratory simulation study with different fluid infusion rates showed that a fluid warmer using magnetic induction is superior to a warmer using countercurrent heat exchange. We tested whether the simulation-based result is translated into the clinical liver transplantation.MethodsTwo hundred twenty recipients who underwent living donor liver transplantation between April 2009 and October 2011 were initially screened. Seventeen recipients given a magnetic induction warmer (FMS2000) were matched 1 : 1 with those given a countercurrent heat exchange warmer (Level-1 H-1000) based on propensity score. Matched variables included age, gender, body mass index, model for end-stage liver disease score, graft size and time under anesthesia. Core temperatures were taken at predetermined time points.Results Level-1 and FMS groups had comparable core temperature throughout the surgery from skin incision, the beginning/end of the anhepatic phase to skin closure. (P = 0.165, repeated measures ANOVA). The degree of core temperature changes within the dissection, anhepatic and postreperfusion phase were also comparable between the two groups. The minimum intraoperative core temperature was also comparable (Level 1, 35.6℃ vs. FMS, 35.4℃, P = 0.122).ConclusionsA countercurrent heat exchange warmer and magnetic induction warmer displayed comparable function regarding the maintenance of core temperature and prevention of hypothermia during living donor liver transplantation. The applicability of the two devices in liver transplantation needs to be evaluated in various populations and clinical settings.

Suction test to demonstrate the peritoneal edge during laparoscopic extraperitoneal inguinal hernia repair

Inadequate peritoneal dissection from retroperitoneal structures may account for a large number of hernia recurrences amongst surgeons and trainees who are new to totally extraperitoneal (TEP) laparoscopic inguinal hernia repair. In this paper, we describe a simple dynamic test that allows surgeons to better appreciate the peritoneal edge during the initial dissection phase of TEP inguinal hernia repair, allowing for more adequate dissection of the peritoneum from retroperitoneal structures before placement of mesh. Data from a single surgeon was collected on 113 consecutive patients who underwent laparoscopic TEP inguinal hernia repair at the Royal North Shore Hospital in Sydney. The data was retrospectively reviewed to determine the number of cases in which the suction test led to further peritoneal dissection prior to mesh placement. After balloon dissection of the pre-peritoneal space and initial dissection of peritoneum and sac from retroperitoneal structures, a laparoscopic suction device is used to aspirate the insufflated gas from the pre-peritoneal space to cause the peritoneum to bulge anteriorly, thus demonstrating the edge of the peritoneal reflection. Further dissection is performed if deemed necessary at this point, and the mesh is placed over the hernia defect. 136 TEP hernia repairs were performed in 113 patients. In 26 (23 %) of patients, the abovementioned technique was of particular value resulting in further dissection of peritoneum prior to mesh placement. There were no complications as a direct result of the test. This dynamic suction test is a risk-free and useful operative tool for surgeons and trainees who are new to TEP inguinal hernia repair, and provides a definitive way of identifying the peritoneal reflection to ensure the peritoneum has been dissected adequately prior to mesh placement.

Augmented reality to the rescue of the minimally invasive surgeon. The usefulness of the interposition of stereoscopic images in the Da Vinci™ robotic console

Computerized management of medical information and 3D imaging has become the norm in everyday medical practice. Surgeons exploit these emerging technologies and bring information previously confined to the radiology rooms into the operating theatre. The paper reports the authors' experience with integrated stereoscopic 3D-rendered images in the da Vinci surgeon console. Volume-rendered images were obtained from a standard computed tomography dataset using the OsiriX DICOM workstation. A custom OsiriX plugin was created that permitted the 3D-rendered images to be displayed in the da Vinci surgeon console and to appear stereoscopic. These rendered images were displayed in the robotic console using the TilePro multi-input display. The upper part of the screen shows the real endoscopic surgical field and the bottom shows the stereoscopic 3D-rendered images. These are controlled by a 3D joystick installed on the console, and are updated in real time. Five patients underwent a robotic augmented reality-enhanced procedure. The surgeon was able to switch between the classical endoscopic view and a combined virtual view during the procedure. Subjectively, the addition of the rendered images was considered to be an undeniable help during the dissection phase. With the rapid evolution of robotics, computer-aided surgery is receiving increasing interest. This paper details the authors' experience with 3D-rendered images projected inside the surgical console. The use of this intra-operative mixed reality technology is considered very useful by the surgeon. It has been shown that the usefulness of this technique is a step toward computer-aided surgery that will progress very quickly over the next few years.

Analysis of Instrument Traffic During Laparoscopic Robot-Assisted Pancreaticoduodenectomy

Context Robotic surgery entails specific issues that are not present, or are not equally relevant, in open surgery or conventional laparoscopy. Instrument traffic (IT) is one of such issues. IT is the time during which surgery is paused because the surgeon at the console is waiting for the action of the surgeon the table (e.g., instrument change, camera cleaning, introduction/withdrawal of needles). Objective We provide the first objective evaluation of IT during robotic pancreaticoduodenectomy (PD). Methods The operative videos of 12 robot-assisted PDs were reviewed to define IT. The analysis included: crude IT time (CITT), relative IT time (RITT) (defined as the percentage of operative time spent for IT), number of robotic instruments changes (RIC), time spent for RIC (TRIC), number of pure laparoscopic actions (PLA), and time spent for PLA (TPLA). Figures were estimated for the entire operation as well as for dissection and reconstruction phases. Details on pancreaticojejunostomy (PJ) or hepaticojejunostomy (HJ) were related to IT to define their relative impact on operative time. Results Mean operative time was 517 min (range 420-600 min). Mean CITT was 3,681.6 sec (RITT 11.89%). Mean RIC or PLA was 315.7. Each RIC or PLA paused surgery for 11.8 sec. Mean RIC was 184.4 (TRIC 2,633.8 sec). Mean PLA was 131.4 (TPLA 1,039.5 sec). Mean dissection time was 326.9 min. Mean CITT was 2,095.1 sec (RITT 10.68%). Mean RIC was 105.8 (TRIC 1,645.2 sec). Mean PLA was 35.7 (TPLA 382.5 sec). Each RIC or PLA paused surgery for 14.4 sec. PJ was made by invaginating technique or duct-to-mucosa. The last one required fewer stitches, but did not reduced CITT or RIC. HJ was performed using either 4 half running sutures or interrupted external stitches plus inner half running sutures. Despite similar CITT the former technique was associated with fewer RIC. Conclusions Some 12% of operative time of laparoscopic robot-assisted PD is wasted because of IT. Since in this series operative time of robotic PD averaged 517 minutes, IT prolonged surgery of more than one hour. Technology improvements and/or refinements in surgical technique are expected to reduce IT during robotic PD.

Lessons from liver transplantation

Lessons from liver transplantation

Continuous Cerebral Blood Flow Autoregulation Monitoring in Patients Undergoing Liver Transplantation

Clinical monitoring of cerebral blood flow (CBF) autoregulation in patients undergoing liver transplantation may provide a means for optimizing blood pressure to reduce the risk of brain injury. The purpose of this pilot project is to test the feasibility of autoregulation monitoring with transcranial Doppler (TCD) and near-infrared spectroscopy (NIRS) in patients undergoing liver transplantation and to assess changes that may occur perioperatively. We performed a prospective observational study in 9 consecutive patients undergoing orthotopic liver transplantation. Patients were monitored with TCD and NIRS. A continuous Pearson's correlation coefficient was calculated between mean arterial pressure (MAP) and CBF velocity and between MAP and NIRS data, rendering the variables mean velocity index (Mx) and cerebral oximetry index (COx), respectively. Both Mx and COx were averaged and compared during the dissection phase, anhepatic phase, first 30min of reperfusion, and remaining reperfusion phase. Impaired autoregulation was defined as Mx≥0.4. Autoregulation was impaired in one patient during all phases of surgery, in two patients during the anhepatic phase, and in one patient during reperfusion. Impaired autoregulation was associated with a MELD score>15 (p=0.015) and postoperative seizures or stroke (p<0.0001). Analysis of Mx categorized in 5mmHg bins revealed that MAP at the lower limit of autoregulation (MAP when Mx increased to≥0.4) ranged between 40 and 85mmHg. Average Mx and average COx were significantly correlated (p=0.0029). The relationship between COx and Mx remained when only patients with bilirubin>1.2mg/dL were evaluated (p=0.0419). There was no correlation between COx and baseline bilirubin (p=0.2562) but MELD score and COx were correlated (p=0.0458). Average COx was higher for patients with a MELD score>15 (p=0.073) and for patients with a neurologic complication than for patients without neurologic complications (p=0.0245). These results suggest that autoregulation is impaired in patients undergoing liver transplantation, even in the absence of acute, fulminant liver failure. Identification of patients at risk for neurologic complications after surgery may allow for prompt neuroprotective interventions, including directed pressure management.