Intraoperative hypotension affects postoperative acute kidney injury depending on the invasiveness of abdominal surgery: A retrospective cohort study

Intraoperative hypotension (IOH) or highly invasive surgery adversely affects postoperative clinical outcomes. It is, however, unclear whether IOH affects postoperative acute kidney injury (AKI) depending on the invasiveness of abdominal surgery. We speculated that IOH in highly invasive abdominal surgery is a significant risk factor for postoperative AKI. We retrospectively reviewed the data of 448 patients who underwent abdominal surgery. Patients were divided into 3 groups: highly (such as pancreaticoduodenectomy and hepatectomy), moderately (open abdominal surgery), and minimally (laparoscopic surgery) invasive surgeries. The association between the time-weighted average (TWA) of mean arterial pressure (MAP) values (≤60 and ≤ 55 mm Hg) and AKI occurrences in each group was assessed. Postoperative AKI occurred after highly, moderately, and minimally invasive surgeries in 33 of 222 (14.9%), 14 of 110 (12.7%), and 12 of 116 (10.3%) cases, respectively (P = .526). The median [interquartile range] of TWA-MAP ≤ 60 mm Hg, as an IOH parameter, was 0.94 [0.33-2.08] mm Hg in highly, 0.54 [0.16-1.46] mm Hg in moderately, and 0.14 [0.03-0.57] mm Hg in minimally invasive surgeries (P < 0001). In addition, there was a significant association between TWA-MAP and AKI in highly invasive surgery, unlike in moderately and minimally invasive surgery, with adjusted odds ratios (95% confidence interval) for TWA-MAP ≤ 60 and ≤ 55 mm Hg associated with AKI of 1.23 [1.00-1.52] (P = .049) and 1.55 [1.02-2.36] (P = .041), respectively. Intraoperative MAP ≤ 60 mm Hg in highly invasive abdominal surgery is associated with postoperative AKI, compared to moderately and minimally invasive surgeries. Additionally, low MAP thresholds in highly invasive surgery increase postoperative AKI risk.

Qualitative and Quantitative Assessment of Invasive Surgery Skill Based on a Custom Training Simulator

PURPOSE

Qualitative and quantitative assessment of interventional performance is a vital component in the evaluation of endovascular surgery skill training. We established a custom simulator with qualitative and quantitative metrics for endovascular performance training.

METHODS

The simulator included an in vitro silicone phantom, mock circulation loop, visual module, force-sensing module, and custom software for image and force data postprocessing. Two tasks to deliver the guidewire to the target location of the carotid artery were conducted by the expert (n=4), novice (n=6), and test (n=4) groups. Seven features with significant differences extracted from the expert and novice groups were applied for qualitative assessment using the support vector machine (SVM) and quantitative assessment using the Mahalanobis distance (MD).

RESULTS

Significant differences were observed in kinematic and force data between experts and novices during the intervention procedure. The median value of finished time for task 1 was 26.88 seconds for experts and 63.36 seconds for novices. The maximum speed for experts and novices was 32.79 and 7.43 cm/s, respectively. Moreover, the classified results depicted that the accuracy of qualitative assessment for task 1 and task 2 was 96.67% and 90%, respectively. As for the quantitative data, the residents had higher scores than individuals majored in biomedical engineering at 2 tasks (70.06±5.30 vs 41.81±6.58 for task 1, p=0.001).

CONCLUSIONS

The proposed endovascular intervention skill training simulator provides qualitative and quantitative metrics on intervention performance skills and may be a useful tool in future interventional surgical training.

CLINICAL IMPACT

This simulator comprised an in-vitro silicone phantom, mock circulation loop, visual module, force-sensing module, and custom software for image and force data post-processing. Seven interventional performance features were used for qualitative assessment using the support vector machine and quantitative assessment using the Mahalanobis Distance. From the observations, we conclude that this endovascular intervention skill training simulator provides qualitative and quantitative metrics on intervention performance and may be a useful tool in future surgical training.

Modeling and control of cable-driven continuum robot used for minimally invasive surgery

Continuum robot has great advantages in minimally invasive surgery (MIS) due to the slenderness and dexterity. But the friction and backlash result in the low trajectory tracking accuracy. This paper aims to study the transmission process of the driving force and the error compensation method. The statics is performed considering the frictional transmission process, and the variation of friction force with driving force is revealed by the model. The hysteresis effect of the tip trajectory is revealed. Then the relationship between the load history and the robot shape is studied, next, the deflection of the robot subject to the different loading forces can be predicted. The correctness of the mechanical model is verified by numerical simulation and experiments. Furthermore, the control methods according to the cable length and the driving force are compared respectively, and a method of error compensation according to the cable length is worked out considering the mechanical model. The rationality of the compensation method is validated by experiment. The results show that the compensation method based on cable length greatly improves the control accuracy, and the maximum deviation is 1.08 mm. The established model and compensation method create conditions for clinical application of the proposed continuum robot.

Does Preoperative Thrombocytopenia in Patients Undergoing Robotic Hepatectomy for Liver Tumors Predict Poor Outcomes? A Propensity-Score Match Analysis

INTRODUCTION

Thrombocytopenia is a known surrogate marker for cirrhosis and portal hypertension and has been associated with increased risk of poor perioperative outcomes when studied in "open" operations. This study was undertaken to assess thrombocytopenia as an independent risk factor for undesirable perioperative outcomes after robotic hepatectomy.

METHODS

We retrospectively reviewed 279 patients who underwent robotic hepatectomy at our institution. Patients were stratified into two cohorts based on preoperative platelet counts. Thrombocytopenia was classified as having a platelet count less than 150 /μL. Patients were 2:1 ratio propensity-score matched based on IWATE score and age. Data are presented as median (mean ± SD).

RESULTS

Thirty-six patients with thrombocytopenia were matched to 72 patients without thrombocytopenia. Patients with thrombocytopenia had higher MELD scores [p = 0.02] and higher Child-Pugh Scores [p <0.001]. Intraoperatively, patients with thrombocytopenia had shorter operative duration [p = 0.03] but similar estimated blood loss (EBL) [p = 0.78]. Postoperatively, there were more fresh frozen plasma transfusions in patients with thrombocytopenia [p = 0.04]. There were no differences in IWATE scores, tumor size, conversions to "open" operations, intraoperative complications, patient length of stay (LOS), Clavien-Dindo score ≥ III complications, perioperative RBC transfusion, in-hospital mortality, or 30-day readmissions.

CONCLUSIONS

In our propensity-score matched study, patients with thrombocytopenia had more severe liver disease; however, there were no differences in their EBL, LOS, or perioperative complications. Preoperative thrombocytopenia, while being an indicator of severity of liver disease potentially promoting perioperative bleeding, does not negatively affect the perioperative course of patients undergoing robotic hepatectomy.

Evaluating the Cost for Robotic vs "Non-Robotic" Transhiatal Esophagectomy

INTRODUCTION

This study was undertaken to analyze and compare the cost of robotic transhiatal esophagectomy (THE) to "non-robotic" THE (ie, "open" and laparoscopic).

METHODS

With IRB approval, we prospectively followed 82 patients who underwent THE. We analyzed clinical outcomes and perioperative charges and costs associated with THE. To compare profitability, the robotic approach was analyzed against "non-robotic" approaches of THE using F-test, Mann-Whitney U test/Student's t-test, and Fisher's exact test. Statistical significance was reported as P ≤0.05. Data are presented as median (mean ± SD).

RESULTS

67 patients underwent the robotic approach, and 15 patients underwent "non-robotic" approach; 4 were "open" and 11 were laparoscopic. 79 patients had adenocarcinoma. Operative duration for robotic THE was 327 (331 ± 82.8) vs 213 (225 ± 62.0) minutes (P = 0.0001) and estimated blood loss was 150 (184 ± 136.1) vs 300 (476 ± 708.7) mL (P = 0.0001). Length of stay was 7 (11 ± 11.8) vs 8 (12 ± 10.6) days (P = 0.76). 16 patients had post-operative complications with a Clavien-Dindo score of three or more. Hospital charges for robotic THE were $197,405 ($259,936 ± 203,630.8) vs "non-robotic" THE $159,588 ($201,565 ± $185,763.5) (P = 0.31). Cost of care for robotic THE was $34,822 ($48,844 ± $45,832.8) vs "non-robotic" THE was $23,939 ($39,386 ± $44,827.2) (P = 0.47). Payment received for robotic THE was $14,365 ($30,003 ± $40,874.7) vs "non-robotic" THE was $28,080 ($41,087 ± $44,509.1) (P = 0.41). 15% of robotic operations were profitable vs 13% of "non-robotic" operations.

CONCLUSIONS

Patients were predominantly older overweight men who had adenocarcinoma of the esophagus. The robotic approach had increased operative time and minimal blood loss. More than a fourth of operations included concomitant procedures. Patients were discharged approximately one week after THE. Overall, the robotic approach has no apparent significant differences in charges, cost, or profitability.

Mucosal Invasion, but Not Incomplete Excision, Has Negative Impact on Long-Term Survival in Patients With Extramammary Paget's Disease

Background

Extramammary Paget’s disease (EMPD) sometimes spreads from the skin to mucosal areas, and curative surgical excision of these areas is challenging. The aim of this study is to analyze the impact of mucosal involvement and surgical treatment on the survival of patients with EMPD.

Methods

We conducted a retrospective review of 217 patients with EMPD. We also assessed the associations between tumor involvement in boundary areas (anal canal, external urethral meatus, vaginal introitus), prognostic factors, and survival in 198 patients treated with curative surgery.

Results

Of 217 patients, 75 (34.6%) had mucosal boundary area involvement. Lesions in these areas were associated with frequent lymphovascular invasion (p = 0.042), lymph node metastasis (p = 0.0002), incomplete excision (p < 0.0001), and locoregional recurrence (p < 0.0001). Boundary area involvement was an independent prognostic factor associated with disease-specific survival, per multivariate analysis (HR: 11.87, p = 0.027). Incomplete excision was not significantly correlated with disease-specific survival (HR: 1.05, p = 0.96).

Conclusion

Boundary area tumor involvement was a major risk factor for incomplete excision, local recurrence, and poor survival outcomes. However, incomplete removal of primary tumors was not significantly associated with poor prognosis. A less invasive surgical approach for preserving anogenital and urinary functions may be acceptable as the first-line treatment for resectable EMPD.

Invasive surgery reduces infarct size and preserves cardiac function in a porcine model of myocardial infarction

Reperfusion injury following myocardial infarction (MI) increases infarct size (IS) and deteriorates cardiac function. Cardioprotective strategies in large animal MI models often failed in clinical trials, suggesting translational failure. Experimentally, MI is induced artificially and the effect of the experimental procedures may influence outcome and thus clinical applicability. The aim of this study was to investigate if invasive surgery, as in the common open chest MI model affects IS and cardiac function. Twenty female landrace pigs were subjected to MI by transluminal balloon occlusion. In 10 of 20 pigs, balloon occlusion was preceded by invasive surgery (medial sternotomy). After 72 hrs, pigs were subjected to echocardiography and Evans blue/triphenyl tetrazoliumchloride double staining to determine IS and area at risk. Quantification of IS showed a significant IS reduction in the open chest group compared to the closed chest group (IS versus area at risk: 50.9 ± 5.4% versus 69.9 ± 3.4%, P = 0.007). End systolic LV volume and LV ejection fraction measured by echocardiography at follow-up differed significantly between both groups (51 ± 5 ml versus 65 ± 3 ml, P = 0.033; 47.5 ± 2.6% versus 38.8 ± 1.2%, P = 0.005). The inflammatory response in the damaged myocardium did not differ between groups. This study indicates that invasive surgery reduces IS and preserves cardiac function in a porcine MI model. Future studies need to elucidate the effect of infarct induction technique on the efficacy of pharmacological therapies in large animal cardioprotection studies.

A surgical technique using the ovarian vein in non-human primate models of potential living-donor surgery of uterus transplantation

AIM

Living donor surgery in organ transplantation should be performed in a minimally invasive manner under conditions that are as safe as possible. The objective of this study is to examine whether the procedure for using the ovarian vein makes donor surgery less invasive in a cynomolgus monkey model of potential living-donor surgery of uterus transplantation.

MATERIAL AND METHODS

Twenty-two female cynomolgus monkeys aged 6-9 years and with body weights of 3.55 ± 1.28 kg were used in the study. Vessels and tissues surrounding the uterus were dissected while preserving the uterine artery/vein. The deep uterine vein was used as a venous pedicle in four monkeys (Group 1), and the ovarian vein was used instead of the deep uterine vein in 18 monkeys (Group 2). With the uterine artery/vein and deep uterine vein (Group 1) or ovarian vein (Group 2) connected to the uterus, the vaginal canal was cut. The vessels were then clamped to produce a donor surgery model. Surgical time, intraoperative organ and vascular injury were examined in each animal.

RESULTS

The average surgical time from laparotomy to clamping of vessels was 230 ± 112 min in all 22 cynomolgus monkeys, and significantly longer in Group 1 (n = 4) than in Group 2 (n = 18) (393 ± 71 vs. 194 ± 84 min, p < 0.05). Surgical time in Group 2 showed a tendency to decrease in animals treated later in the study, with a significantly longer time in the first 10 monkeys compared with the last 8 (253 ± 65 vs. 120 ± 26 min, p < 0.05). All monkeys had no complications, including no injuries to other organs and no unanticipated vascular injury.

CONCLUSION

The procedure using the ovarian vein was less invasive than that using the deep uterine vein in mimicking living-donor surgery in a cynomolgus monkey model of uterus transplantation.