Iatrogenic ureteral injury in colorectal cancer surgery: a nationwide study comparing laparoscopic and open approaches

Iatrogenic urinary injuries in colorectal surgery: outcomes and risk factors from a nationwide cohort

BACKGROUND

Iatrogenic urinary injury (IUI) can lead to significant complications after colorectal surgery, especially when diagnosis is delayed. This study analyzes risk factors associated with IUI and delayed IUI among patients undergoing colorectal procedures.

METHODS

Adults undergoing colorectal surgery between 2012 and 2021 were identified in the American College of Surgeons National Surgical Quality Improvement Program (NSQIP®) database. Multivariable regression analysis was used to determine risk factors and outcomes associated with IUI and delayed IUI.

RESULTS

Among 566,036 patients, 5836 patients (1.0%) had IUI after colorectal surgery, of whom 236 (4.0%) had delayed IUI. Multiple preoperative risk factors for IUI and delayed IUI were identified, with disseminated cancer [adjusted odds ratio (aOR) 1.4, 95% confidence interval (CI) 1.2-1.5; p < 0.001] and diverticular disease [aOR 1.1, 95% CI 1.0-1.2; p = 0.009] correlated with IUI and increased body mass index [aOR 1.6, 95% CI 1.2-2.1; p = 0.003] and ascites [aOR 5.6, 95% CI 2.1-15.4; p = 0.001] associated with delayed IUI. Laparoscopic approach was associated with decreased risk of IUI [aOR 0.4, 95% CI 0.4-0.5; p < 0.001] and increased risk of delayed IUI [aOR 1.8, 95% CI 1.4-2.5; p < 0.001]. Both IUI and delayed IUI were associated with significant postoperative morbidity, with severe multiorgan complications seen in delayed IUI.

CONCLUSIONS

While IUI occurs infrequently in colorectal surgery, unrecognized injuries can complicate repair and cause other negative postoperative outcomes. Patients with complex intra-abdominal pathology are at increased risk of IUI, and patients with large body habitus undergoing laparoscopic procedures are at increased risk of delayed IUI.

Deep Learning-Based Real-Time Ureter Identification in Laparoscopic Colorectal Surgery

BACKGROUND

Iatrogenic ureteral injury is a serious complication of abdominopelvic surgery. Identifying the ureters intraoperatively is essential to avoid iatrogenic ureteral injury. We developed a model that may minimize this complication.

IMPACT OF INNOVATION

We applied a deep learning-based semantic segmentation algorithm to the ureter recognition task and developed a deep learning model called UreterNet. This study aimed to verify whether the ureters could be identified in videos of laparoscopic colorectal surgery.

TECHNOLOGY, MATERIALS, AND METHODS

Semantic segmentation of the ureter area was performed using a convolutional neural network-based approach. Feature Pyramid Networks were used as the convolutional neural network architecture for semantic segmentation. Precision, recall, and the Dice coefficient were used as the evaluation metrics in this study.

PRELIMINARY RESULTS

We created 14,069 annotated images from 304 videos, with 9537, 2266, and 2266 images in the training, validation, and test data sets, respectively. Concerning ureter recognition performance, the precision, recall, and Dice coefficient for the test data were 0.712, 0.722, and 0.716, respectively. Regarding the real-time performance on recorded videos, it took 71 milliseconds for UreterNet to infer all pixels corresponding to the ureter from a single still image and 143 milliseconds to output and display the inferred results as a segmentation mask on the laparoscopic monitor.

CONCLUSIONS

UreterNet is a noninvasive method for identifying the ureter in videos of laparoscopic colorectal surgery and can potentially improve surgical safety.

FUTURE DIRECTIONS

Although this deep learning model could lead to the development of an image-navigated surgical system, it is necessary to verify whether UreterNet reduces the occurrence of iatrogenic ureteral injury.

Preventing iatrogenic ureteral injury in colorectal surgery: a comprehensive and systematic review of the last 2 decades of literature and future perspectives

Iatrogenic ureteral injury (IUI) during colorectal surgery is a rare complication but related to a serious burden of morbidity. This comprehensive and systematic review aims to provide a critical overview of the most recent literature about IUI prevention techniques in colorectal surgery. We performed a comprehensive and systematic review of studies published from 2000 to 2022 and assessed the use of techniques for ureteral injury prevention and intraoperative localization. 26 publications were included, divided into stent-based (prophylactic/lighted ureteral stent and near-infrared fluorescent ureteral catheter [PUS/LUS/NIRFUC]) and fluorescent dye (FD) groups. Costs, the percentage and number of IUIs detected, reported limitations, complication rates and other outcome points were compared. The IUI incidence rate ranged from 0 to 1.9% (mean 0.5%) and 0 to 1.2% (mean 0.3%) in the PUS/LUS/NIRFUC and FD groups, respectively. The acute kidney injury (AKI) and urinary tact infection (UTI) incidence rate ranged from 0.4 to 32.6% and 0 to 17.3%, respectively, in the PUS/LUS/NIRFUC group and 0-15% and 0-6.3%, respectively, in the FD group. Many other complications were also compared and descriptively analyzed (length-of-stay, mortality, etc.). These techniques appear to be feasible and safe in select patients with a high risk of IUI, but the delineation of reliable guidelines for preventing IUI will require more randomized controlled trials.

Long-term economic outcomes of ureteral injury in the United States

OBJECTIVES

Ureteral injuries (UIs) during surgical procedures can have serious consequences for patients. Although UIs can result in substantial clinical burden, few studies report the impact of these injuries on payer reimbursement and patient cost-sharing. This retrospective study evaluated 30-day, 90-day, and 1-year healthcare resource utilization for patients with UIs and estimated patient and payer costs.

METHODS

Patients aged ≥ 12 years who underwent abdominopelvic surgery from January 2016 to December 2018 were identified in a United States claims database. Patients were followed for 1 year to estimate all-cause healthcare visits and costs for patients and payers. Surgeries resulting in UIs within 30 days from the surgery date were matched to surgeries without UIs to estimate UI-attributable visits and costs.

RESULTS

Five hundred and twenty-two patients with UIs were included. Almost a third (29.9%) of patients with UIs had outpatient surgery. Patients with UIs had slightly more healthcare visits and a 15.3% higher 30-day hospital readmission rate than patients without UIs. Patient costs due to UIs were not statistically significant, but annual payer costs attributable to UIs were $38,859 (95% CI = 28,142-49,576), largely driven by inpatient costs.

CONCLUSIONS

UIs add substantial cost for payers and result in more healthcare visits for patients. These findings highlight the importance of including inpatient and outpatient settings for UI prevention. Although UIs are rare, the associated patient and payer burdens are high; thus, protocols or techniques are needed to recognize and avert UIs as current guideline recommendations are lacking.

Iatrogenic ureteral injury: What should the digestive surgeon know?

PURPOSE OF THE STUDY

Iatrogenic ureteral injury (IUI) is a rare but formidable complication of any abdominal or pelvic surgery. The aim of this study was to describe the epidemiology of IUI in colorectal surgery in the Basse-Normandie region over the period 2004-2022, as well as to review the literature on the management of this complication.

MATERIALS AND METHODS

This multicenter retrospective analysis of clinical data (medical records and operative reports) concerned 22 patients (13 men and 9 women) who suffered an IUI during colorectal surgery between 2004 and 2022. Ureteral resections for oncological purposes and endoluminal instrumental injuries (post-ureteroscopy) were excluded from the study. We also carried out a review of the literature concerning the incidence of IUI in colorectal surgery.

RESULTS

The incidence of IUI was 0.27% over the study period (22 ureteral injuries out of 8129 colorectal procedures). Colorectal cancer and sigmoid diverticulitis were the dominant surgical indications (85% of cases). Proctectomy and left colectomy were the most performed resection procedures (75% of cases). Surgery was scheduled in 68% of cases. The approach was open laparotomy in 59% and laparoscopy in 41% of cases. The IUI involved the left ureter in 63% of cases and the pelvic ureter in 77% of cases. Conservative endoscopic treatment by insertion of a double-J catheter stent had a success rate of 87.5%. Surgical repairs consisting of re-implantation techniques and uretero-ureteral anastomosis had a success rate of 75%. The nephrectomy rate was 13.6% (3/22) and the mortality rate 9% (2/22). A literature review identified sixteen studies, where the incidence of IUI varied from 0.1 to 4.5%.

FINDINGS

IUI occurring during colorectal surgery is a rare occurrence but remain a formidable complication. No means of prevention has proven its effectiveness to date, but guidance devices using illuminated ureteral catheters or dyes seem to constitute a promising approach. Injuries to the left pelvic ureter are the most common, and the majority can be treated endoscopically if diagnosed early.

Risk stratification of acute kidney injury (AKI) following ureteral stent insertion for colorectal surgery

INTRODUCTION AND OBJECTIVES

Ureteral stents have long been utilized during colorectal resections to assist in the identification of ureters intraoperatively and mitigate risk of ureteral injury. As these procedures have shifted toward robot-assisted laparoscopic methods, lighted stents have increasingly been used. The incidence of acute kidney injury (AKI) following bilateral ureteral stent placement has been reported to be as high as 41.9%. We sought to identify our single-institution risk and determine the extent to which age, sex, and stent type affected incidence of AKI.

METHODS

A retrospective analysis was performed at a single community hospital of all open and robotic-assisted laparoscopic colorectal surgeries from October 2012 to April 2022. If requested, ureteral stents were placed bilaterally by a urologist and later removed by the surgeon. Non-lighted stents used were 5 Fr whistle-tip (BARD); lighted stents were 6 Fr with a fiberoptic core (STRYKER). Kidney failure was described as a rise of creatinine to ≥ 1.5 times the preoperative value, per KDIGO guidelines.

RESULTS

633 consecutive colorectal surgeries were evaluated, with no stents placed in 237 cases, non-lighted stents placed in 137 cases, and lighted stents placed in 259 cases. No ureteral injuries were observed. Overall incidence of AKI for non-stented surgeries was 0.8% vs 5.8% for non-lighted stents and 5.8% for lighted stents. Patient age was the most significant factor in AKI incidence: for patients under 60, there was no statistical difference in AKI incidence for stented vs non-stented procedures (2.2% vs 1.1%). For patients over 60, the risk of AKI was 10.5% for stented vs 0.7% for non-stented. Female patients had statistically significant risk differences, with AKI incidence of 7.1% stented vs 0.0% non-stented. AKI completely resolved in all cases, regardless of cohort.

CONCLUSIONS

In patients under age 60, the use of stents was not associated with an increased risk of AKI. For women and those over 60, stents pose a higher risk of transient AKI. Overall incidence of AKI in our larger and single-institution community hospital population was significantly lower than reported in other studies. No statistical difference was observed, overall, in AKI incidence between lighted and non-lighted stents.

The Use of Prophylactic Ureteric Stents in Major Abdomino-Pelvic Sarcoma Surgery: Risks, Benefits, and Potential Complications

Here we present two cases of post-operative obstructive renal failure following major abdomino-pelvic sarcoma surgery. In both cases, prophylactic ureteric stents were inserted to aid the identification and protection of the ureters during resection of these complex retroperitoneal masses. In case one, obstructive renal failure occurred following ureteric stent removal on day 0 post-operatively. In case two, obstructive renal failure developed on day 1 post-operatively despite having a ureteric stent in situ. Here we propose that a combination of reflex anuria/ureteric edema and papillary sloughing led to the obstructive renal failure in both cases. Re-insertion of bilateral ureteric stents in case one, and replacement of a right ureteric stent in case two saw prompt excretion of urine and sloughy debris with rapid improvement of renal function. This article presents these cases in detail and further reviews the use of prophylactic ureteric stents in major abdomino-pelvic surgery along with the current guidelines for their usage.

Prediction of Ureteral Injury During Colorectal Surgery Using Machine Learning

BACKGROUND

Ureteral injury (UI) is a rare but devastating complication during colorectal surgery. Ureteral stents may reduce UI but carry risks themselves. Risk predictors for UI could help target the use of stents, but previous efforts have relied on logistic regression (LR), shown moderate accuracy, and used intraoperative variables. We sought to use an emerging approach in predictive analytics, machine learning, to create a model for UI.

METHODS

Patients who underwent colorectal surgery were identified in the National Surgical Quality Improvement Program (NSQIP) database. Patients were split into training, validation, and test sets. The primary outcome was UI. Three machine learning approaches were tested including random forest (RF), gradient boosting (XGB), and neural networks (NN), and compared with traditional LR. Model performance was assessed using area under the curve (AUROC).

RESULTS

The data set included 262,923 patients, of whom 1519 (.578%) experienced UI. Of the modeling techniques, XGB performed the best, with an AUROC score of .774 (95% CI .742-.807) compared with .698 (95% CI .664-.733) for LR. Random forest and NN performed similarly with scores of .738 and .763, respectively. Type of procedure, work RVUs, indication for surgery, and mechanical bowel prep showed the strongest influence on model predictions.

CONCLUSIONS

Machine learning-based models significantly outperformed LR and previous models and showed high accuracy in predicting UI during colorectal surgery. With proper validation, they could be used to support decision making regarding the placement of ureteral stents preoperatively.

2023 WSES guidelines for the prevention, detection, and management of iatrogenic urinary tract injuries (IUTIs) during emergency digestive surgery

Iatrogenic urinary tract injury (IUTI) is a severe complication of emergency digestive surgery. It can lead to increased postoperative morbidity and mortality and have a long-term impact on the quality of life. The reported incidence of IUTIs varies greatly among the studies, ranging from 0.3 to 1.5%. Given the high volume of emergency digestive surgery performed worldwide, there is a need for well-defined and effective strategies to prevent and manage IUTIs. Currently, there is a lack of consensus regarding the prevention, detection, and management of IUTIs in the emergency setting. The present guidelines, promoted by the World Society of Emergency Surgery (WSES), were developed following a systematic review of the literature and an international expert panel discussion. The primary aim of these WSES guidelines is to provide evidence-based recommendations to support clinicians and surgeons in the prevention, detection, and management of IUTIs during emergency digestive surgery. The following key aspects were considered: (1) effectiveness of preventive interventions for IUTIs during emergency digestive surgery; (2) intra-operative detection of IUTIs and appropriate management strategies; (3) postoperative detection of IUTIs and appropriate management strategies and timing; and (4) effectiveness of antibiotic therapy (including type and duration) in case of IUTIs.

Fluorescence-guided surgery: comprehensive review

BACKGROUND

Despite significant improvements in preoperative workup and surgical planning, surgeons often rely on their eyes and hands during surgery. Although this can be sufficient in some patients, intraoperative guidance is highly desirable. Near-infrared fluorescence has been advocated as a potential technique to guide surgeons during surgery.

METHODS

A literature search was conducted to identify relevant articles for fluorescence-guided surgery. The literature search was performed using Medical Subject Headings on PubMed for articles in English until November 2022 and a narrative review undertaken.

RESULTS

The use of invisible light, enabling real-time imaging, superior penetration depth, and the possibility to use targeted imaging agents, makes this optical imaging technique increasingly popular. Four main indications are described in this review: tissue perfusion, lymph node assessment, anatomy of vital structures, and tumour tissue imaging. Furthermore, this review provides an overview of future opportunities in the field of fluorescence-guided surgery.

CONCLUSION

Fluorescence-guided surgery has proven to be a widely innovative technique applicable in many fields of surgery. The potential indications for its use are diverse and can be combined. The big challenge for the future will be in bringing experimental fluorophores and conjugates through trials and into clinical practice, as well as validation of computer visualization with large data sets. This will require collaborative surgical groups focusing on utility, efficacy, and outcomes for these techniques.

Simultaneous, Multi-Channel, Near-Infrared Fluorescence Visualization of Mesenteric Lymph Nodes Using Indocyanine Green and Methylene Blue: A Demonstration in a Porcine Model

Near-infrared fluorescence (NIRF) image-guided surgery is a useful tool that can help reduce perioperative complications and improve tissue recognition. Indocyanine green (ICG) dye is the most frequently used in clinical studies. ICG NIRF imaging has been used for lymph node identification. However, there are still many challenges in lymph node identification by ICG. There is increasing evidence that methylene blue (MB), another clinically applicable fluorescent dye, can also be useful in the intraoperative fluorescence-guided identification of structures and tissues. We hypothesized that MB NIRF imaging could be used for lymph node identification. The aim of this study was to evaluate the feasibility of intraoperative lymph node fluorescence detection using intravenously (IV) administered MB and compare it to ICG via a camera that has two dedicated near-infrared (NIR) channels. Three pigs were used in this study. ICG (0.2 mg/kg) was administered via a peripheral venous catheter followed by immediate administration of MB (0.25 mg/kg). NIRF images were acquired as video recordings at different time points (every 10 min) over an hour using the QUEST SPECTRUM® 3 system (Quest Medical Imaging, Middenmeer, The Netherlands), which has two dedicated NIR channels for simultaneous intraoperative fluorescence guidance. The 800 nm channel was used to capture ICG fluorescence and the 700 nm channel was used for MB. The target (lymph nodes and small bowel) and the background (vessels-free field of the mesentery) were highlighted as the regions of interest (ROIs), and corresponding fluorescence intensities (FI) from these ROIs were measured. The target-to-background ratio (TBR) was then computed as the mean FI of the target minus the mean FI of the background divided by the mean FI of the background. In all included animals, a clear identification of lymph nodes was achieved at all time points. The mean TBR of ICG in lymph nodes and small bowel was 4.57 ± 1.00 and 4.37 ± 1.70, respectively for the overall experimental time. Regarding MB, the mean TBR in lymph nodes and small bowel was 4.60 ± 0.92 and 3.27 ± 0.62, respectively. The Mann-Whitney U test of the lymph node TBR/small bowel TBR showed that the TBR ratio of MB was statistically significantly higher than ICG. The fluorescence optical imaging technology used allows for double-wavelength assessment. This feasibility study proves that lymph nodes can be discriminated using two different fluorophores (MB and ICG) with different wavelengths. The results suggest that MB has a promising potential to be used to detect lymphatic tissue during image-guided surgery. Further preclinical trials are needed before clinical translation.

Trends and benefits of prophylactic ureter catheters in the era of minimally invasive surgery

BACKGROUND

The recent spike in ureter injury (UI) amidst the rise of minimally invasive surgery (MIS) has focused attention on the propriety of prophylactic ureter catheters (PUCs) for abdominopelvic operations.

METHODS

A retrospective review of PUCs for rectal cancer resection following neoadjuvant therapy, combined with a comprehensive literature review.

RESULTS

There were zero UI in the current study. Literature review revealed a nationwide spike in PUCs in the last 30 years, dependent on operation: 1) colorectal resection-increased from 1.1% to 4.4%, 2) sigmoid colectomy for diverticulitis-increased from 6.7% to 16.3%. This 2-4 fold increase parallels the rise of MIS: 15 of the 20 latest studies (75%) either combined open operations and MIS (4 studies) or focused solely on MIS (11 studies). Medial-to-lateral dissection identified as a UI risk factor. Only 20-30% of UI identified intraoperatively.

CONCLUSIONS

Intraoperative UI is missed in 70-80% of cases. The prevention, identification, ease of ureter repair, and net decrease in operative time support the use of PUCs. Medial-to-lateral dissection is identified as a potential contributing factor to UI.

Prevention of ureteral injury during laparoscopic colorectal cancer surgery with horseshoe kidney using fluorescent ureteral catheters: a case report

BACKGROUND

Horseshoe kidney is one of the most common congenital renal fusion anomalies and is characterized by abnormalities in the position, rotation, vascular supply, and ureteral anatomy of the kidney. When performing surgery for colorectal cancer in patients with horseshoe kidneys, anatomical identification is important to avoid organ injuries. Several reports on surgery for colorectal cancer with horseshoe kidneys have described the usefulness of three-dimensional (3D) computed tomography (CT) angiography for detecting abnormalities in vascular supply. However, few reports have focused on the prevention of ureteral injury in surgery for colorectal cancer with horseshoe kidney, despite abnormalities in the ureteral anatomy. Here, we report a case in which laparoscopic sigmoid colon resection for sigmoid colon cancer with a horseshoe kidney was safely performed using fluorescent ureteral catheters.

CASE PRESENTATION

A 60-year-old Japanese man presented to our hospital testing positive for fecal occult blood. Colonoscopy revealed sigmoid colon cancer, and CT confirmed a horseshoe kidney. The 3D-CT angiography showed aberrant renal arteries from the aorta and right common iliac artery, and the left ureter passed across the front of the renal isthmus. A fluorescent ureteral catheter was placed in the left ureter before the surgery to prevent ureteral injury. Laparoscopic sigmoid colon resection with D3 lymph node dissection was performed. The fluorescent ureteral catheter enabled the identification of the left ureter that passed across the front of the renal isthmus and the safe mobilization of the descending and sigmoid colon from the retroperitoneum. The operative time was 214 min, with intraoperative bleeding of 25 mL. The patient's postoperative course was good: no complications arose and she was discharged on the seventh postoperative day.

CONCLUSION

In patients with horseshoe kidney, the use of fluorescent ureteral catheters and 3D-CT angiography enables safer laparoscopic surgery for colorectal cancer. We recommend the placement of fluorescent ureteral catheters in such surgeries to prevent ureteral injury.

Robot-assisted laparoscopic surgery with a fluorescent near-infrared ray ureteral catheter for a rectal cancer patient with pelvic kidney: A case report

An 85-year-old woman presented with a stomachache after a meal and was admitted to the previous clinic. Multi-detector computed tomography (CT) of the abdomen showed wall thickening in the rectum and right ectopic pelvic kidney. Colonoscopy revealed a mass at the rectum, and a biopsy showed adenocarcinoma. CT showed no lymphadenopathy or distant metastasis. Hartmann's procedure with fluorescent near-infrared ray ureteral catheters was used to avoid causing urinary injury. Robotic surgery was performed while checking the route of the ureter in near-infrared mode. The patient was discharged on postoperative day 14 without specific complications. This case appears to be the first of robot-assisted laparoscopic surgery for a rectal cancer patient with pelvic kidney.

Oral and Parenteral vs. Parenteral Antibiotic Prophylaxis for Patients Undergoing Laparoscopic Colorectal Resection: An Intervention Review with Meta-Analysis

This study aims to systematically assess the efficacy of parenteral and oral antibiotic prophylaxis compared to parenteral-only prophylaxis for the prevention of surgical site infection (SSI) in patients undergoing laparoscopic surgery for colorectal cancer resection. Published and unpublished randomized clinical trials comparing the use of oral and parenteral prophylactic antibiotics vs. parenteral-only antibiotics in patients undergoing laparoscopic colorectal surgery were collected searching electronic databases (MEDLINE, CENTRAL, EMBASE, SCIENCE CITATION INDEX EXPANDED) without limits of date, language, or any other search filter. The outcomes included SSIs and other infectious and noninfectious postoperative complications. Risk of bias was assessed using the Cochrane revised tool for assessing risk of bias in randomized trials (RoB 2). A total of six studies involving 2252 patients were finally included, with 1126 cases in the oral and parenteral group and 1126 cases in the parenteral-only group. Meta-analysis results showed a statistically significant reduction of SSIs (OR 0.54, 95% CI 0.40 to 0.72; p < 0.0001) and anastomotic leakage (OR 0.55, 95% CI 0.33 to 0.91; p = 0.02) in the group of patients receiving oral antibiotics in addition to intravenous (IV) antibiotics compared to IV alone. Our meta-analysis shows that a combination of oral antibiotics and intravenous antibiotics significantly lowers the incidence of SSI compared with intravenous antibiotics alone.

Safety and Clinical Value of Prophylactic Ureteral Stenting Before Cytoreductive Surgery With Hyperthermic Intraperitoneal Chemotherapy

BACKGROUND

Prophylactic ureteral stents (PUS) are typically placed prior to complex abdominal or pelvic operations at the surgeon's discretion to help facilitate detection of iatrogenic ureteral injury. However, its usefulness and safety in the setting of cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) have not been examined. This study aims to evaluate the potential clinical value and risk profile of prophylactic ureteral stent placement prior to CRS-HIPEC.

METHODS

We performed a single-institutional retrospective analysis of 145 patients who underwent CRS-HIPEC from 2013 to 2021. Demographic and operative characteristics were compared between patients who underwent PUS placement and those that did not. Ureteral stent-related complications were evaluated.

RESULTS

Of the 145 patients included in the analysis, 124 underwent PUS placement. There were no significant differences in patient demographics, medical comorbidities, or tumor characteristics. Additionally, PUS placement did not significantly increase operative time and was not associated with increased pelvic organ resection. However, patients who underwent prophylactic ureteral stenting had significantly higher peritoneal carcinomatosis index score (15.1 vs 9.1, P=.002) and increased rate of ureteral complications (24.2% vs 14.3%, P=.04), which led to lengthened hospital stay (13.2 days vs 8.1 days, P= .03). Notably, the sole ureteral injury and three cases of hydronephrosis were seen in patients who underwent PUS.

CONCLUSION

Prophylactic ureteral stent placement in patients undergoing CRS-HIPEC may be useful, particularly in patients with predetermined extensive pelvic disease. However, PUS placement is not without potential morbidity and should be selectively considered in patients for whom benefits outweigh the risks.

X-ray-activated persistent luminescence nanomaterials for NIR-II imaging

Persistent luminescence is not affected by background autofluorescence, and thus holds the promise of high-contrast bioimaging. However, at present, persistent luminescent materials for in vivo imaging are mainly bulk crystals characterized by a non-uniform size and morphology, inaccessible core-shell structures and short emission wavelengths. Here we report a series of X-ray-activated, lanthanide-doped nanoparticles with an extended emission lifetime in the second near-infrared window (NIR-II, 1,000-1,700 nm). Core-shell engineering enables a tunable NIR-II persistent luminescence, which outperforms NIR-II fluorescence in signal-to-noise ratios and the accuracy of in vivo multiplexed encoding and multilevel encryption, as well as in resolving mouse abdominal vessels, tumours and ureters in deep tissue (~2-4 mm), with up to fourfold higher signal-to-noise ratios and a threefold greater sharpness. These rationally designed nanoparticles also allow the high-contrast multiplexed imaging of viscera and multimodal NIR-II persistent luminescence-magnetic resonance-positron emission tomography imaging of murine tumours.

Ureteral injuries in colorectal surgery and the impact of laparoscopic and robotic-assisted approaches

BACKGROUND

Ureteral injury is a feared complication in colorectal surgery that has been increasing over the past decade. Some have attributed this to an increased adoption of minimally invasive surgery (MIS), but the literature is hardly conclusive. In this study we aim to further assess the overall trend of ureteral injuries in colorectal surgery, and investigate propensity adjusted contributions from open and MIS to include robotic-assisted surgery.

METHODS

This is a retrospective analysis of colorectal surgeries from 2006 to 2016 using the Nationwide Inpatient Sample (NIS) database. Multivariable logistic regression was performed to identify predisposing and protective factors. Demographics, hospital factors, and case-mix differences for open and MIS were accounted for via propensity analysis. The NIS coding structure changed in 2015, which could introduce a potential source of incongruity in complication rates over time. As a result, all statistical analyses included only the first nine years of data, or were conducted before and after the change for comparison.

RESULTS

Of 514,162 colorectal surgeries identified there were 1598 ureteral injuries (0.31%). Ureteral injuries were found to be increasing through 2015 (2.3/1000 vs 3.3/1000; p < 0.001) and through the coding transition to 2016 (4.8/1000; p < 0.001). This trend was entirely accounted for by injuries made during open surgery, with decreasing injury rates for MIS over time. Adjusted odds ratio (OR) for ureteral injury with all MIS vs. open cases was 0.81 (95% CI 0.70-0.93, p = 0.003) and for robotic-assisted surgery alone versus open cases was 0.50 (95% CI 0.33-0.77, p = 0.001).

CONCLUSIONS

The incidence rate of ureteral injuries during open colorectal surgery is increasing over time, but have been stable or decreasing for MIS cases. These findings hold even after using propensity score analysis. More research is needed to further delineate the impact of MIS and robotic-assisted surgery on ureteral injuries.

Clinical experience with near-infrared ray catheter, a fluorescent ureteral catheter, on laparoscopic surgery for colon diverticulitis: A case report

RATIONALE

As the world's population ages, the number of surgical cases of colovesical fistulas secondary to colon diverticulitis is also expected to increase. The key issue while performing laparoscopic surgery for these fistulas is the avoidance of iatrogenic ureteral injury. There are no reports of Near-infrared Ray Catheter being used in surgery for diverticulitis, which is one of the diseases with the highest risk of ureteral injury. We present a case of a male patient with colovesical fistulas secondary to sigmoid colon diverticulitis who underwent laparoscopic surgery with visualization of the ureter using a new surgical technique in laparoscopic surgery.

PATIENTS CONCERN

An 82-year-old man presented to our urological department with general fatigue and air and fecal matter in the urine.

DIAGNOSES

Cystography showed delineation of the sigmoid colon. Abdominal computed tomography findings revealed multiple sigmoid colon diverticula with thickened walls as well as large stones and a small amount of air in the bladder. He was diagnosed with a urinary tract infection with colovesical fistulas and bladder stones due to sigmoid diverticulitis.

INTERVENTIONS

After the creation of a transverse colostomy, we scheduled a laparoscopic anterior resection and cystolith removal.

OUTCOMES

Severe inflammatory adhesions around the sigmoid colon and a high risk of ureteral injury were expected preoperatively. After induction of anesthesia, we inserted a Near-infrared Ray Catheter, a fluorescent ureteral catheter, which allowed us to easily identify and visualize the ureter in real-time. This allowed bowel dissection without concerns of ureteral injury. The operative time for the gastrointestinal part of the procedure was 150 minutes, and the patient was in a good general condition after the operation and was discharged on postoperative day 7.

LESSONS

The course of the ureter was easily and quickly identified by the green fluorescence from the ureteral catheter during laparoscopic surgery for fistulas associated with diverticulitis, where severe inflammation and dense fibrosis were present. Our technique is an easy and feasible approach that provides real-time urethral navigation during surgery for colovesical fistulas secondary to colon diverticulitis.

Iatrogenic Ureteral Injury and Prophylactic Stent Use in Veterans Undergoing Colorectal Surgery

INTRODUCTION

Iatrogenic ureteral injury (IUI) is an uncommon complication in colorectal surgery. Prophylactic ureteral stenting (PUS) gained acceptance to aid in intraoperative identification of the ureter. Despite its use, the benefit of pus to avoid IUI remains debatable. We sought to analyze the rates of IUI after colorectal surgery in veterans and to compare the outcomes after PUS using a large matched cohort.

METHODS

The veterans affairs surgical quality improvement program database was queried for patients who underwent colorectal surgery from 2008-2015. To analyze the outcomes of PUS, we created two matched groups using propensity-score matching accounting for demographical and clinical cofactors to assess variable outcomes. Cross-tabulation was used to calculate rates of IUI and univariate and multivariate analyses were performed to evaluate risk factors associated with IUI.

RESULTS

27,448 patients were identified and 458 underwent PUS placement (1.6%). The majority of procedures were performed electively and with an open approach. Mean age was 65 y, 96.3% were male, and colorectal cancer was the most common indication. 45 patients (0.2%) were diagnosed with IUI. IUI incidence was higher in female patients, after left-sided colorectal resection, and in those undergoing open procedures. After matching, PUS use was associated with longer length of stay and operative time and increased creatinine levels from baseline.

CONCLUSION

We demonstrated that the use of PUS is independently associated with increased operative time and change in creatinine levels. Although no IUI occurred in the PUS group, this finding was not statistically significant. The risk and/or benefit ratio of PUS should be considered for each individual case, with its selective use based on the presence of risk factors for IUI, such as female patients and left-sided resections.

Management of intraoperative complications during laparoscopic right colectomy

BACKGROUND

Minimally invasive right colectomy is increasingly performed as standard treatment for diseases of right colon. Complete mesocolic excision has been introduced for cancer treatment to improve oncological results. Both standard and complete mesocolic excision techniques are associated with intraoperative complications. The purpose of this study was to analyse incidence and management of intraoperative complications in patients who underwent laparoscopic right colectomy with complete mesocolic excision in a single institution.

METHODS

This is a retrospective study conducted in a single Italian centre from April 2017 to October 2020. Data of non-metastatic cancer patients who underwent laparoscopic right colectomy were collected to analyse onset of intraoperative complications, their management and rate of conversion to open surgery.

RESULTS

A total of 92 patients were included in this study. The 1.09% of patients were converted to open surgery due to adhesions and bowel occlusion. The 5.43% of patients had intraoperative complications: bleeding from Henle's trunk, pre-pancreatic plane and ileocolic artery stump account for 3.26%, gonadal vessel injury for 1.09% and bowel lesion for 1.09%.

CONCLUSIONS

Despite the limits of this study, it shows that bleeding is one of the most frequent complications in laparoscopic right colectomy. Bleeding, occlusion and adhesions are most common reasons for conversion to open surgery.

Management of intraoperative complications during laparoscopic left colectomy

INTRODUCTION

Minimally invasive surgery has gained a major role in the current management of colorectal disease since the introduction of laparoscopy in the early 1990s for colorectal procedures. The laparoscopic approach, in fact, is not exempt from the risk of intraoperative complications, some of which can occur outside the field of view. Aim of this chapter is to review the different types of complications that can happen during left colectomy, analyzing the causes, how to prevent them and what to do in case they occur.

EVIDENCE ACQUISITION

A literature search was carried out using the MEDLINE and PubMed databases for studies published between January 1980 and October 2020. The following terms were used for the search: complications, risk factors, colorectal surgery, colorectal resection, laparoscopy, left colectomy, intraoperative complications, splenic injury, intraoperative bleeding.

EVIDENCE SYNTHESIS

From our literature search we identified twenty-four studies, including two systematic reviews and metanalyses, that were the most pertinent to the subject.

CONCLUSIONS

Many different complications can occur during laparoscopic left colectomy. Maintaining control of the situation is important to provide a prompt solution to the occurred injury. Increasing the reporting rate of complications may help, in the future, to analyze the causes and improve management strategies, keeping in mind that the only surgeon who does not have complications is the one who does not operate.

Intraoperative ureter identification with a novel fluorescent catheter

Iatrogenic ureteral injuries (IUI) occur in 0.5-1.3% of cases during abdominal surgery. If not recognized intraoperatively, IUI increase morbidity/mortality. A universally accepted method to prevent IUI is lacking. Near-infrared fluorescent imaging (NIRF), penetrating deeper than normal light within the tissue, might be useful, therefore ureter visualization combining NIRF with special dyes (i.e. IRDye 800BK) is promising. Aim of this work is to evaluate the detection of ureters using stents coated with a novel biocompatible fluorescent material (NICE: near-infrared coating of equipment), during laparoscopy. female pigs underwent placement of NICE-coated stents (NS). NIRF was performed, and fluorescence intensity (FI) was computed. Successively, 0.15 mg/kg of IRDye 800BK was administered intravenously, and FI was computed at different timepoints. Ureter visualization using NS only was further assessed in a human cadaver. Both methods allowed in vivo ureter visualization, with equal FI. However, NS were constantly visible whereas IRDye 800BK allowed visualization exclusively during the ureteral peristaltic phases. In the human cadaver, NS provided excellent ureter visualization in its natural anatomical position. NS provided continuous ureteral visualization with similar FI as the IRDye 800BK, which exclusively allowed intermittent visualization, dependent on ureteral peristalsis. NS might prove useful to visualize ureters intraoperatively, potentially preventing IUI.

Complicated Diverticular Disease

The modern management of colonic diverticular disease involves grouping patients into uncomplicated or complicated diverticulitis, after which the correct treatment paradigm is instituted. Recent controversies suggest overlap in management strategies between these two groups. While most reports still support surgical intervention for the treatment of complicated diverticular disease, more data are forthcoming suggesting complicated diverticulitis does not merit surgical resection in all scenarios. Given the significant risk for complication in surgery for diverticulitis, careful attention should be paid to patient and procedure selection. Here, we define complicated diverticulitis, discuss options for surgical intervention, and explain strategies for avoiding operative pitfalls that result in early and late postoperative complications.

Surgical complications in colorectal cancer patients

BACKGROUND

Advancements in diagnostic and therapeutic sciences have allowed early diagnosis and treatment of cancer. Colorectal cancer is one of the most commonly reported cancers, particularly in elderly patients.

METHODS

Open and laparoscopic surgeries are used for the removal of the tumor, along with chemotherapy, depending on the stage of cancer. However, colorectal cancer surgery is associated with a great number of complications, that affect the efficacy of the surgery and overall health and survival of the patient.

RESULTS

Prevalence of these complications have shown discrepancies depending on the condition of the patient and disease and surgical skills of the surgeon. Preoperative evaluation, intraoperative care and postoperative measures can reduce the incidence of these complications.

CONCLUSION

This review highlights some frequently reported complications associated with colorectal cancer surgery, their risk factors and subsequent therapeutic measures to treat them.

A Near-Infrared Fluorescent Probe Coated with β-Cyclodextrin Molecules for Real-Time Imaging-Guided Intraoperative Ureteral Identification and Diagnosis

Although iatrogenic ureteral injury and its lack of recognition due to ureteral invisibility are serious incidents in open and laparoscopic abdominal surgeries, there are currently no safe and effective methods for intraoperative ureteral identification (IUI) and diagnosis (IUD). In this study, I designed and chemically synthesized a near-infrared fluorescence (NIRF) imaging probe (CD-NIR-1) and evaluated its clearance and ability for IUI and IUD in animal models. CD-NIR-1 demonstrated high specificity and ultrarapid clearance by rat kidneys to the urinary bladder following intravenous administration of a single dose (25 nmol/kg of body weight), with 96% of the dose ultimately excreted at the first urination with no chemical modification. Furthermore, urine containing CD-NIR-1 in ureters showed strong NIRF, thereby enabling IUI and IUD via NIRF imaging. These results demonstrated the efficacy of CD-NIR-1 for clinical use.

Factors influencing harmonized health data collection, sharing and linkage in Denmark and Switzerland: A systematic review

INTRODUCTION

The digitalization of medicine has led to a considerable growth of heterogeneous health datasets, which could improve healthcare research if integrated into the clinical life cycle. This process requires, amongst other things, the harmonization of these datasets, which is a prerequisite to improve their quality, re-usability and interoperability. However, there is a wide range of factors that either hinder or favor the harmonized collection, sharing and linkage of health data.

OBJECTIVE

This systematic review aims to identify barriers and facilitators to health data harmonization-including data sharing and linkage-by a comparative analysis of studies from Denmark and Switzerland.

METHODS

Publications from PubMed, Web of Science, EMBASE and CINAHL involving cross-institutional or cross-border collection, sharing or linkage of health data from Denmark or Switzerland were searched to identify the reported barriers and facilitators to data harmonization.

RESULTS

Of the 345 projects included, 240 were single-country and 105 were multinational studies. Regarding national projects, a Swiss study reported on average more barriers and facilitators than a Danish study. Barriers and facilitators of a technical nature were most frequently reported.

CONCLUSION

This systematic review gathered evidence from Denmark and Switzerland on barriers and facilitators concerning data harmonization, sharing and linkage. Barriers and facilitators were strictly interrelated with the national context where projects were carried out. Structural changes, such as legislation implemented at the national level, were mirrored in the projects. This underlines the impact of national strategies in the field of health data. Our findings also suggest that more openness and clarity in the reporting of both barriers and facilitators to data harmonization constitute a key element to promote the successful management of new projects using health data and the implementation of proper policies in this field. Our study findings are thus meaningful beyond these two countries.

The effects of rectal cancer surgery on the anatomical localisation of ureters - a prospective observational study

Introduction

Anatomical changes after surgery and fibrotic adhesions increase the organ laceration risk, including that of the ureter, in recurrent cases and secondary operations. The aim of this study was to investigate the changes in the anatomical localisations of the ureters via computed tomography urography in patients undergoing rectal cancer surgery.

Material and methods

The study involved prospectively collected data on the changes of ureteral location preoperatively and postoperatively in patients with operated rectal cancer. Distances (mm) of ureters determined midline in the computed tomography urogram phase.

Results

A total of 18 patients were included. The mean distances between the right (R₁) and left (L₁) ureters and the mid-vertebral line before the surgery were 30.9 ±5.4 mm and 34.5 ±9.9 mm, respectively. The postoperative distances between them (R₂ and L₂) were 26.4 ±9.1 mm and 29.5 ±9.9 mm, respectively. The R₂ measurement showed that 83.3% (15/18) of the right ureters had deviated medially, whereas 16.7% (3/18) of them had deviated laterally. The L₂ measurements showed that 88.8% (16/18) of the left ureters had deviated medially, whereas 11.2% (2/18) of them had deviated laterally. The differences between the preoperative and postoperative measurements of the right and left ureter positions were 4.5 ±9.2 mm and 4.9 ±4.6 mm, respectively, with the displacement in the left ureter being statistically significant (p ≤ 0.001).

Conclusions

Rectal cancer surgery causes medially deviated changes in the positions of the ureters.

Incidence and Clinical Outcomes of Gonadal Artery Injury during Colorectal Surgery in Male Patients

BACKGROUND

Gonadal artery is susceptible to accidental injury due to their anatomical proximity to the colon and rectum. There are few literature reviews focusing on this injury during colorectal surgery. We conduct a retrospective study to evaluate the incidence and the clinical significance of these injuries in terms of testicular size and testicular enhancement on the contrast CT scan.

METHODS

Patients' characteristic data included age, body mass index (BMI), diagnosis, operation type, cause of gonadal artery injury, side of injury, level of injury, method of vessel ligation, and follow-up period. We measured the testicular sizes before and after gonadal artery injury and measured the enhancement level by recording the mean attenuation value on the injury side and non-injury side of the testis on the CT scan.

RESULTS

The incidence of gonadal artery injury was 3.61% and 15 male patients with this injury were enrolled. There were 5 patients with iatrogenic injury and 10 patients with non-iatrogenic injury due to advanced tumor or inflammation. No patients had any complaints of testicular discomforts or atrophy after the surgery. The testicular sizes before and after the surgery showed no significant difference (p = 0.877). The mean attenuation values of the injury side and non-injury side of the testis also showed no significant difference (p = 0.79).

CONCLUSIONS

Gonadal artery injury during colorectal surgery is not a rare complication. To prevent this injury, knowledge of the anatomy and staying in the proper plane of dissection are the key points. In patients with gonadal artery injury during colorectal surgery, sacrifice of the gonadal artery is safe without clinical significance in terms of testicular size and testicular enhancement on the contrast CT scan.

Routine prophylactic ureteral stenting before cytoreductive surgery and hyperthermic intraperitoneal chemotherapy: Safety and usefulness from a single-center experience

OBJECTIVE

There are very few evidences about safety and usefulness of routine prophylactic ureteral stenting (PUS) before cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC).

MATERIAL AND METHODS

An analysis of prospectively collected data about patients who underwent CRS and HIPEC for different sites of primary disease was carried out focusing on ureteral complications.

RESULTS

A total of 138 patients who underwent CRS and HIPEC between December 2010 and June 2017 were considered. All patients underwent PUS before CRS and HIPEC. Of them, 91 (66.4%) patients received pelvic peritonectomy, 49 (35.8%) pelvic lymphadenectomy, 31 (22.6%) left hemicolectomy, 44 (32.4%) right hemicolectomy, 46 (33.6%) rectal resection, 56 (40.9%) hysteroannessiectomy, and 39 (28.5%) appendectomy. There was one (0.7%) postoperative ureteral fistula. The cumulative risk of ureteral stent-related major complications was 4.3% (two patients (1.4%) had protracted gross hematuria, two patients (1.4%) had urinary sepsis, and three patients (2.9%) developed hydronephrosis after a period from removing ureteral stents and required restenting. Morbidity due to ureteral stenting was associated with a longer length of stay (LOS) (p=0.053). A total of 52 patients (44.1%) developed renal dysfunction according to the RIFLE (Risk, Injury, Failure, Loss of kidney function, End-stage kidney-disease) criteria: 19.5% were in risk class, 10.2% in acute renal injury class, and 14.4% in acute renal failure class.

CONCLUSION

PUS could be a useful tool for reducing iatrogenic ureteral injury, but it is associated with a non-negligible morbidity, which implies longer LOS. A more accurate patient selection for PUS is necessary.

A zwitterionic near-infrared fluorophore for real-time ureter identification during laparoscopic abdominopelvic surgery

Iatrogenic injury of the ureters is a feared complication of abdominal surgery. Zwitterionic near-infrared fluorophores are molecules with geometrically-balanced, electrically-neutral surface charge, which leads to renal-exclusive clearance and ultralow non-specific background binding. Such molecules could solve the ureter mapping problem by providing real-time anatomic and functional imaging, even through intact peritoneum. Here we present the first-in-human experience of this chemical class, as well as the efficacy study in patients undergoing laparoscopic abdominopelvic surgery. The zwitterionic near-infrared fluorophore ZW800-1 is safe, has pharmacokinetic properties consistent with an ideal blood pool agent, and rapid elimination into urine after a single low-dose intravenous injection. Visualization of structure and function of the ureters starts within minutes after ZW800-1 injection and lasts several hours. Zwitterionic near-infrared fluorophores add value during laparoscopic abdominopelvic surgeries and could potentially decrease iatrogenic urethral injury. Moreover, ZW800-1 is engineered for one-step covalent conjugatability, creating possibilities for developing novel targeted ligands.

Iatrogenic injury of the ureters is a feared complication of laparoscopic abdominal surgery. Here the authors present the NIR fluorophore ZW800-1 as an intraoperative imaging agent for ureter mapping, showing its safety, pharmacokinetic properties, and efficacy in healthy volunteers and patients undergoing abdominopelvic surgery.

The sentinel stent? A systematic review of the role of prophylactic ureteric stenting prior to colorectal resections

PURPOSE

'Prophylactic' ureteric stents potentially reduce rates, and facilitate intraoperative recognition, of iatrogenic ureteric injury (IUI) during colorectal resections. A lack of consensus surrounds the risk-benefit equation of this practice, and we aimed to assess the evidence base.

METHODS

A systematic review was performed according to PRISMA guidelines. MEDLINE, Scopus, EMBASE and Cochrane databases were searched using terms 'ureteric/ureteral/JJ/Double J stent' or 'ureteric/ureteral catheter' and 'colorectal/prophylactic/resection/diverticular disease/diverticulitis/iatrogenic injury'. Primary outcomes were rates of ureteric injuries and their intraoperative identification. Secondary outcomes included stent complication rates.

RESULTS

We identified 987 publications; 22 papers met the inclusion criteria. No randomised controlled trials were found. The total number of patients pooled for evaluation was 869,603 (102,370 with ureteric stents/catheters, 767,233 controls). The most frequent indications for prophylactic stents were diverticular disease (45.38%), neoplasia (33.45%) and inflammatory bowel disease (9.37%). Pooled results saw IUI in 1521/102,370 (1.49%) with, and in 1333/767,233 (0.17%) without, prophylactic ureteric stents. Intraoperative recognition of IUIs occurred in 10/16 injuries (62.5%) with prophylactic stents, versus 9/17 (52.94%) without stents (p = 0.579). The most serious complications of prophylactic stent use were ureteric injury (2/1716, 0.12%) and transient ureteric obstruction following stent removal (13/666, 1.95%).

CONCLUSIONS

Placement of prophylactic ureteric stents has a low complication rate. There is insufficient evidence to conclude that stents decrease ureteric injury or increase intraoperative detection of IUIs. Apparently higher rates of IUI in stented patients likely reflect use in higher risk resections. A prospective registry with harmonised data collection points and stratification of intraoperative risk is needed.

Urological Injuries during Colorectal Surgery

The proximity of the colon and rectum to the organs of the urologic system virtually ensures that iatrogenic urologic injuries become a distinct possibility during complex colorectal surgical procedures. An intimate knowledge of urogenital anatomy as well as strategies for identification and repair of potential injuries is of paramount importance. Attention is mandated when operating within the narrow confines of the pelvis, as this is where these structures are most at risk. The ureters are at highest risk of injury, followed by the bladder and urethra. The nature of these injuries encompasses both functional and mechanical morbidities. Patient factors, including prior pelvic surgery, radiation, inflammatory bowel disease, infectious processes, and urogenital abnormalities all increase the risk of injury. As colorectal surgeons encounter an increasing number of patients with the above risk factors, it is important to be familiar with the various urologic injury patterns, their diagnosis, and appropriate management.

Near-infrared fluorescence laparoscopy of the ureter with three preclinical dyes in a pig model

Background

Ureteric injury is reported to occur in 1–7.6% of colorectal surgeries. To reduce the incidence of ureteral injury, it is essential to identify the ureters. The use of near-infrared fluorescence (NIRF) imaging with intravenously administered dyes might be of added value for ureteral visualization during laparoscopy. The aim of this study is to assess the performance of three preclinical dyes; IRDye^® 800BK, IRDye^® 800NOS and IRDye^® 800CW, for near-infrared fluorescence laparoscopy of the ureter in pigs.

Methods

In three female Dutch landrace pigs, the new dyes were evaluated. In each pig, 1 dye was tested using a 6-mg intravenous dose in a concentration of 1 mg/ml. Imaging was performed in fluorescence mode and white light mode with a laparoscopic imaging system. In order to further evaluate the dyes, an ex vivo imaging experiment was performed, in which 8 decreasing concentrations per dye, diluted in PBS, were evaluated in a transparent test tube with NIRF mode at a distance of 1, 5 and 10 cm from the laparoscope.

Results

All three dyes were effective in allowing the identification of the ureter with NIRF imaging. The ureter became fluorescent after 35, 45 and 10 min, respectively, for IRDye^® 800BK, IRDye^® 800NOS and IRDye^® 800CW with a maximum target-to-background ratio (TBR) of 2.14, 0.66 and 1.44, respectively. In the ex vivo imaging experiment, all three dyes produced a strong fluorescence signal at all concentrations and all distances evaluated.

Conclusions

Intravenous administration of the preclinical dyes IRDye^® 800CW, IRDye^® 800 BK and IRDye^® 800NOS facilitated successful identification of the anatomical course of the ureter in living pig models. The highest measured TBR occurred with the use of IRDye^® 800BK. Ex vivo, a correlation was observed between the fluorescence intensities of the signal with the concentration of the dye and with the distance to the object.

Ureteral Injury During Colorectal Surgery: Two Case Reports and a Literature Review

Iatrogenic ureteral injury (IUI) is a dreaded complication of abdominopelvic surgery. Although rare, it is associated with severe consequences. This complication most commonly occurs during gynecological procedures but may also occur during colorectal surgeries. We present two cases of IUI in patients in whom the ureteric stents were electively placed. The first case was a 71-year-old male with no significant medical history. The patient underwent an elective laparoscopic sigmoidectomy for complicated diverticulitis. During the procedure, a proximal IUI occurred, and was recognized and repaired. The second case occurred in a 68-year-old male with a history of multiple complicated abdominal surgeries. The patient underwent a second redo low anterior resection for a long preanastomotic stricture. The IUI occurred in the right fibrosed presacral plane, approximately 3 cm proximal to the bladder. The ureter was reimplanted to the bladder during the same procedure. We will also present a literature review of IUI, including the risk factors, intraoperative prevention, and repair options.

Ureteral stents increase risk of postoperative acute kidney injury following colorectal surgery

BACKGROUND

Ureteral stents are commonly placed before colorectal resection to assist in identification of ureters and prevent injury. Acute kidney injury (AKI) is a common cause of morbidity and increased cost following colorectal surgery. Although previously associated with reflex anuria, prophylactic stents have not been found to increase AKI. We sought to determine the impact of ureteral stents on the incidence of AKI following colorectal surgery.

METHODS

All patients undergoing colon or rectal resection at a single institution between 2005 and 2015 were reviewed using American College of Surgeons National Surgical Quality Improvement Program dataset. AKI was defined as a rise in serum creatinine to ≥ 1.5 times the preoperative value. Univariate and multivariate regression analyses were performed to identify independent predictors of AKI.

RESULTS

2910 patients underwent colorectal resection. Prophylactic ureteral stents were placed in 129 patients (4.6%). Postoperative AKI occurred in 335 (11.5%) patients during their hospitalization. The stent group demonstrated increased AKI incidence (32.6% vs. 10.5%; p < 0.0001) with bilateral having a higher rate than unilateral stents. Hospital costs were higher in the stent group ($23,629 vs. $16,091; p < 0.0001), and patients with bilateral stents had the highest costs. Multivariable logistic regression identified predictors of AKI after colorectal surgery including age, procedure duration, and ureteral stent placement.

CONCLUSIONS

Prophylactic ureteral stents independently increased AKI risk when placed prior to colorectal surgery. These data demonstrate increased morbidity and hospital costs related to usage of stents in colorectal surgery, indicating that placement should be limited to patients with highest potential benefit.

Outcome one year after robot-assisted rectal cancer surgery: a consecutive cohort study

PURPOSE

The aim of this study was to investigate outcome after robot-assisted rectal cancer surgery (RARCS). We focused on conversion rate, postoperative complications, pathological evaluation (adequacy of resection margins), and bowel function (low anterior resection syndrome (LARS)) 1 year after surgery.

METHODS

An observational study of prospectively registered patients with data obtained from medical records. Data comprise the initial 208 rectal cancer patients operated with robot-assisted surgery at a single Danish university hospital from October 2011 to October 2014.

RESULTS

In total, 27 procedures (13%) were converted to open surgery, and 23 of the 27(85%) conversions were in the obese and overweight patients. The anastomotic leak rate was 12 (9%), and further 5 (2%) developed a complication requiring re-operation (ileus, bleeding, wound abscess). In total, 14 (7%) patients had a circumferential resection margin (CRM) ≤ 1 mm (R1-resection). In regard to bowel function, 15/22 (68%) of TME patients had major LARS at 6 months follow-up but at 12 months follow-up this proportion was reduced to 18/34 (53%).

CONCLUSIONS

The outcomes after RARCS at a single high-volume university center are overall comparable to outcomes reported from laparoscopic surgery. The results are satisfying because they are achieved during implementation of RARCS. Randomized trials are, however, needed and focus should especially be on long-term follow-up in regard to functional outcome.

Incidence of Iatrogenic Ureteral Injury During Open and Laparoscopic Colorectal Surgery: A Single Center Experience and Review of the Literature

INTRODUCTION

Iatrogenic ureteral injury is a rare but potentially devastating complication of colorectal surgery. We evaluated the incidence and management of iatrogenic ureteral injuries in colorectal surgery during the transition phase from open to laparoscopic surgery.

MATERIALS AND METHODS

We conducted a retrospective single center study. All patients who underwent colorectal surgery between 2004 and 2014 were evaluated by collecting data of electronic patient charts. Both acute and elective procedures were included.

RESULTS

A total of 3302 colorectal procedures were performed in the study period. Of these, 2817 operations were performed open and 484 laparoscopically. A total of 23 iatrogenic ureteral injuries were identified, of which 5 were found during laparoscopic surgery. The cumulative incidence of ureteral injuries was 0.6% for open procedures and 1.0% for laparoscopic procedures.

CONCLUSIONS

Ureteral injury is a rare complication of colorectal surgery. The incidence might rise with the increasing use of laparoscopy.

Danish Colorectal Cancer Group Database

AIM OF DATABASE

The aim of the database, which has existed for registration of all patients with colorectal cancer in Denmark since 2001, is to improve the prognosis for this patient group.

STUDY POPULATION

All Danish patients with newly diagnosed colorectal cancer who are either diagnosed or treated in a surgical department of a public Danish hospital.

MAIN VARIABLES

The database comprises an array of surgical, radiological, oncological, and pathological variables. The surgeons record data such as diagnostics performed, including type and results of radiological examinations, lifestyle factors, comorbidity and performance, treatment including the surgical procedure, urgency of surgery, and intra- and postoperative complications within 30 days after surgery. The pathologists record data such as tumor type, number of lymph nodes and metastatic lymph nodes, surgical margin status, and other pathological risk factors.

DESCRIPTIVE DATA

The database has had >95% completeness in including patients with colorectal adenocarcinoma with >54,000 patients registered so far with approximately one-third rectal cancers and two-third colon cancers and an overrepresentation of men among rectal cancer patients. The stage distribution has been more or less constant until 2014 with a tendency toward a lower rate of stage IV and higher rate of stage I after introduction of the national screening program in 2014. The 30-day mortality rate after elective surgery has been reduced from >7% in 2001-2003 to <2% since 2013.

CONCLUSION

The database is a national population-based clinical database with high patient and data completeness for the perioperative period. The resolution of data is high for description of the patient at the time of diagnosis, including comorbidities, and for characterizing diagnosis, surgical interventions, and short-term outcomes. The database does not have high-resolution oncological data and does not register recurrences after primary surgery. The Danish Colorectal Cancer Group provides high-quality data and has been documenting an increase in short- and long-term survivals since it started in 2001 for both patients with colon and rectal cancers.

Genitourinary Considerations in Reoperative and Complex Colorectal Surgery

Genitourinary structures are at risk of injury during colorectal surgery. The incidence of injury is low; however, the risk is higher in cases involving severe inflammatory or infectious processes, locally advanced or recurrent cancer, previous radiation, and reoperation. Consideration of the anatomical relationship between the genitourinary system, and the colon and rectum is crucial to avoid injuries. Intraoperative diagnostic techniques such as intravenous pyelogram (IVP), fluoroscopic cystogram, or retrograde urethrogram can aid in identifying suspected injuries. Early recognition and repair of injuries decrease the morbidity of an injury. Repair of injuries depends on the location and extent of the injury. Simple injuries may be repaired primarily, while complex injuries may require more advanced repairs such as a flap reconstruction.

Iatrogenic Bladder Injury: National Analysis of 30-Day Outcomes

OBJECTIVE

To examine the risk factors and outcomes of BI, a rare complication of abdominopelvic surgery.

METHODS

We queried the National Surgical Quality Improvement Program database to identify intraoperative bladder injury (BI) defined by the Current Procedural Terminology code for cystorrhaphy from 2005 to 2013. Propensity-score matching balanced the differences between patients with BI and the controls. The factors matched included age, body mass index, race, modified frailty index, and procedure category.

RESULTS

There were 1685 cases of BI in 1,541,736 surgeries (0.11%). Although 49.5% of surgeries were performed in an open fashion, this approach accounted for 69.3% of BI (P < .001). Prior to matching, mortality rates and morbidity were increased for the BI group (P < .001). Moreover, age, recent chemotherapy or radiation or steroid history, and smoking were among the risk factors for BI (all P < .05). Resident involvement increased the odds of BI and complications after BI, but decreased the risk of readmission (all P < .05). After matching, 30-day mortality was no longer increased for patients with BI (P < .001). Patients with BI requiring repair did have increased median length of stay (6 days [interquartile range {IQR}: 3-11] vs 5 [IQR: 2-9]; P < .001) and operative time (203 min [IQR: 140-278] vs 134 [IQR: 86-199]; P < .001). BI patients were more likely to undergo reoperation (7.7% vs 5.3%; P = .005). Urine infection, sepsis, and bleeding were more likely in the BI group compared with the matched controls (all P < .001). Delayed repair was rare.

CONCLUSION

We present the largest national series assessing iatrogenic BI and subsequent repair. BI increases 30-day complications, reoperation, and length of stay but does not increase 30-day mortality compared with matched controls. More complex surgical cases and increased baseline comorbidity were risk factors for BI.