Iatrogenic ureteral injuries and their prevention in colorectal surgery: results from a nationwide survey

Acute kidney injury after colorectal surgery with prophylactic ureteral stents

BACKGROUND

After colorectal surgery, acute kidney injury (AKI) results from a complex interplay of multiple independent causes and preventive measures that occur during the hospitalization. Prophylactic stenting for ureter identification has been identified as a potential cause, but the evidence is conflicting, possibly because of differing baseline characteristics and procedure-related approaches.

OBJECTIVE

This retrospective cohort study assesses the role of stents in the etiology of AKI after determining the independent predictors of AKI.

METHODS

From a population of 1224 consecutive colorectal patients (from 8/1/2016 through 12/31/2021), 382 (31.2%) received ureteral stents, and propensity score matching was used to create stented and control groups. Emergent cases and patients with sepsis were excluded from the analysis. Previously identified independent predictors of AKI, minimally invasive procedures, and a history of diabetes mellitus were used as criteria to create two balanced groups.

RESULTS

Baseline demographic characteristics and procedure-related factors baseline factors were similar between the groups. There was no difference in the rate of AKI between stented patients and controls (P = 0.82), nor was there any difference in postoperative complications, such as chronic renal insufficiency (CRI, P = 0.49), average postoperative creatinine (P = 0.67), urinary tract infections (UTI, P = 0.82), any postoperative infection (P = 0.48), in-hospital complications (P = 1.00), length of stay (LOS, P = 0.15), and 30-day readmissions (P = 0.79).

CONCLUSIONS

In a population of patients where stenting was frequently employed, ureter stents placed for identification did not appear to cause AKI or AKI-related complications.

Can preoperative ureteral stent placement help in the intraoperative identification of iatrogenic ureteral injury?

BACKGROUND

The benefits of prophylactic ureteral stent placement during colorectal surgery remain controversial. This study aimed to determine the incidence of ureteral injury in colorectal operations, assess the complications associated with stent usage, and determine whether their use leads to earlier identification and treatment of injury.

METHODS

This was a retrospective study of patients undergoing colorectal abdominal operations between 2015 and 2021. Variables were examined for possible association with ureteral stent placement. The primary study endpoint was ureteral injury identified within 30 days postoperatively.

RESULTS

Of 6481 patients who underwent colorectal surgery, 970 (15%) underwent preoperative ureteral stent placement. The use of stents was significantly associated with a higher American Society of Anesthesiologists classification, wound classification, and longer duration of surgery. A ureteral injury was identified in 28 patients (0.4%). Of these patients, 13 had no stent, and 15 had preoperative stents placed. After propensity matching, stent use was associated with an increased risk of hematuria and urinary tract infection. Ureteral injury was identified intraoperatively in 14 of 28 patients (50.0%) and was not associated with ureteral stent use (P = .45).

CONCLUSION

Iatrogenic ureteral injury was uncommon, whereas preoperative stent placement was relatively frequent. Earlier recognition of iatrogenic ureteral injury is not an expected advantage of preoperative ureteral stent placement.

Population Pharmacokinetic Modeling and Simulation of Pudexacianinium (ASP5354) for Dose Setting of a Phase 2 First-in-Patient Study: A Novel Imaging Agent for Intraoperative Ureter Visualization during Abdominopelvic Surgery

Pudexacianinium (ASP5354) chloride is an indocyanine green derivative designed to enable enhanced ureter visualization during surgery. The objective of the present analysis was to determine appropriate doses of pudexacianinium for a phase 2, dose-ranging study (NCT04238481). Real-time urine pudexacianinium concentration is considered a good pharmacodynamic surrogate marker, since ureter visualization likely depends on its concentration in the ureter. Using plasma and urine concentrations of pudexacianinium from a phase 1 single-ascending-dose (0.1-24.0 mg) study in healthy participants, a 3-compartment population pharmacokinetic model with a urine output compartment was developed and effectively described the concentration-time profiles. The individual estimated glomerular filtration rates had a significant impact on drug clearance. Simulations suggested that a 1.0 mg intravenous injection would achieve target urine concentrations over 1 μg/mL (determined from previous nonclinical studies) for 3 hours postdose, assuming a urine production rate of 1.0 mL/min. Based on this simulation, doses of 0.3, 1.0, and 3.0 mg were proposed for the phase 2 study. The observed plasma concentrations were generally consistent with model predictions. For urine, although only limited data could be obtained due to the difficulties of spot urine collection from surgical patients, intraoperative ureter visualization was successful at 1.0 and 3.0 mg.

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.

Ureteral Stents Do Not Increase the Risk for Acute Kidney Injury After Colorectal Surgery

BACKGROUND

Ureteral stents are thought to prevent or help identify ureteral injuries. Studies suggesting that ureteral stents increase the risk of postoperative acute kidney injury show inconsistent conclusions. The large ureteral stenting volume at our institution provided a unique opportunity for granular analysis not previously reported.

OBJECTIVE

To determine whether prophylactic ureteral stenting at colorectal surgery increases acute kidney injury.

DESIGN

Retrospective analysis of colorectal operations with prophylactic ureteral stents was compared to operations without stents. Adjusted analysis was performed with inverse probability treatment weighting.

SETTINGS

Single institution enhanced recovery colorectal surgery service.

PATIENTS

Prospective institutional database between July 1, 2018, and December 31, 2021.

MAIN OUTCOME MEASURE

The primary outcome was acute kidney injury, defined as increase in creatinine ≥0. 3 mg/dL (definition 1) and 1.5-fold increase in creatinine (definition 2) within 48 hours postoperatively.

RESULTS

There were 410 patients in the study population: 310 patients in the stent group and 100 in the no-stent group. There were 8 operative ureteral injuries: 4 (1.29%) in the stent group and 4 (4.0%) in the no-stent group ( p = 0.103). Unadjusted analysis revealed no significant difference in acute kidney injury between groups. After adjustment, there was still no significant difference in acute kidney injury between groups when defined as definition 1 (no-stent 23.76% vs stent 26.19%, p = 0.745) and as definition 2 (no-stent 15.86% vs stent 14.8%, p = 0.867). Subgroup analysis showed that lighted stents were associated with significantly more acute kidney injury than no-stent patients when defined as definition 1 ( p = 0.017) but not when defined as definition 2 ( p = 0.311).

LIMITATIONS

Single-institution results may not be generalizable.

CONCLUSION

Prophylactic ureteral stenting does not increase the risk of acute kidney injury for patients undergoing enhanced recovery colorectal surgery, although caution and further study may be warranted for lighted stents. Studies further examining contrasting roles of ureter stenting and imaging in open and minimally invasive colorectal surgery are warranted. See Video Abstract.

LOS STENTS URETERALES NO AUMENTAN EL RIESGO DE LESIN RENAL AGUDA DESPUS DE LA CIRUGA COLORECTAL

ANTECEDENTES:Se cree que los stents ureterales previenen o ayudan a identificar las lesiones ureterales. Los estudios que sugieren que los stents ureterales aumentan el riesgo de lesión renal aguda post operatoria muestran conclusiones contradictorias. El gran volumen de endoprótesis ureterales en nuestra institución brindó una oportunidad única para el análisis granular que no se informó anteriormente.OBJETIVO:Determinar si la colocación de stent ureteral profiláctico en cirugía colorrectal aumenta el daño renal agudo.DISEÑO:El análisis retrospectivo de operaciones colorrectales con stents ureterales profilácticos se comparó con operaciones sin stents. El análisis ajustado se realizó con ponderación de tratamiento de probabilidad inversa.AJUSTES:Cirugía colorrectal de recuperación mejorada de una sola instituciónPACIENTES:Base de datos institucional prospectiva entre el 01/07/2018 y el 31/12/2021.MEDIDA DE RESULTADO PRINCIPAL:El resultado primario fue la lesión renal aguda definida como un aumento en la creatinina ≥ 0,3 mg/dL (Definición n.° 1) y un aumento de 1,5 veces en la creatinina (Definición n.° 2) dentro de las 48 horas posteriores a la operación.RESULTADOS:Hubo 410 pacientes en la población de estudio: 310 pacientes en el grupo Stent y 100 en el grupo No-Stent. Hubo 8 lesiones ureterales operatorias, 4 (1,29%) en el grupo Stent y 4 (4,0%) en el grupo No-Stent (p = 0,103). El análisis no ajustado no reveló diferencias significativas en la lesión renal aguda entre los grupos. Después del ajuste, todavía no hubo una diferencia significativa en la lesión renal aguda entre los grupos cuando se definió como Definición n.º 1 (sin stent 23,76 % frente a stent 26,19 %, p = 0,745) y por definición n.º 2 (sin stent 15,86 % frente a stent 14,8 %, p = 0,867). El análisis de sub grupos mostró que los stents iluminados se asociaron con una lesión renal aguda significativamente mayor que los pacientes sin stent cuando se definieron como Definición n.º 1 (p = 0,017), pero no cuando se los definió como Definición n.º 2 (p = 0,311).LIMITACIONES:Los resultados de una sola institución pueden no ser generalizables.CONCLUSIÓN:La colocación profiláctica de endoprótesis ureterales no aumenta el riesgo de lesión renal aguda en pacientes que se someten a cirugía colorrectal de recuperación mejorada, aunque es posible que se requiera precaución y estudios adicionales para las endoprótesis iluminadas. Se justifican estudios que examinen más a fondo las funciones contrastantes de la colocación de stents de uréter y las imágenes en la cirugía colorrectal abierta y mínimamente invasiva. (Traducción-Dr. Mauricio Santamaria ).

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.

Burden of Colovesical Fistula and Changing Treatment Pathways: A Systematic Literature Review

PURPOSE

Colovesical fistula (CVF) is a rare complication of sigmoid diverticulitis causing significant morbidity and quality of life impairment. Aim of this study was to analyze contemporary literature data to appraise the current standard of care and changes of treatment algorithms over time.

MATERIALS AND METHODS

A systematic review of the literature on surgical management of CVF was conducted through PUBMED, EMBASE, and COCHRANE databases, according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement guidelines.

RESULTS

Fourteen papers published between 2014 and 2020 and including 1061 patients were analyzed. One-stage colonic resection with primary anastomosis, with or without loop ileostomy, was the most common surgical procedure. A laparoscopic or robotic approach was attempted in 39.5% of patients, and conversion rate to open surgery was 7.8%. Clavien-Dindo grade ≥3 complication rate, 30-day mortality, and recurrence rate were 7.4%, 1.5%, and 0.5%, respectively.

CONCLUSIONS

Minimally invasive sigmoidectomy with primary anastomosis is safe and should be the first-choice approach for CVF. Bladder repair is not necessary after a negative intraoperative leak test. A standardized perioperative care can improve clinical outcomes and reduce the length of hospital stay and the duration of Foley catheterization.

Laparoscopic surgery combined with the double-J tube implantation for the rare cystic-solid schwannoma of seminal vesicle: A Case Report and Literature Review

RATIONALE

Schwannoma is common in young and middle-aged people and occurs in the head, neck, posterior mediastinum, and retroperitoneal. Schwannoma, on the other hand, is a rare occurrence in the seminal vesicle. Early diagnosis and treatment are crucial since the disease can cause lower abdominal pain, nocturia, frequent urination, blood sperm, and other symptoms. There is no standard diagnostic or treatment guideline for seminal vesicle schwannomas currently. Therefore, the treatment experience relies on the few cases reported throughout the world.

PATIENT CONCERNS

A 45-year-old male patient discovered that the tumor beside the right side spermatophore is bigger than 3 years ago.

DIAGNOSIS

Schwannoma of seminal vesicle.

INTERVENTIONS

Ureter double-J tube implantation and laparoscopic surgery for schwannoma of seminal vesicle.

OUTCOMES

The operation process went smoothly. And the patient was no discomfort after half a year.

CONCLUSION

Schwannoma of the seminal vesicle is very rare in the clinic, and the imaging examination was not conclusive. The diagnosis mainly depends on pathological results. Surgical resection is the best treatment method for schwannoma. In surgery for schwannoma of seminal vesicle, combined with the ureter double-J tube implantation are many benefits. This case is an excellent example of the seminal vesicle schwannomas.

Prophylactic Ureteral Catheter Placement Appears to Reduce Intraoperative Ureteric Injury During Resection of Primary Retroperitoneal Liposarcoma

Background: Prophylactic ureteral catheters placement (PUCP) was advocated as an effective strategy for decreasing ureteral morbidities in colorectal surgeries. However, whether it should be routinely used prior to primary retroperitoneal liposarcoma (PRLS) surgeries remains unknown. Methods: It was a retrospective study, conducted at a tertiary sarcoma center. Medical records of patients with PRLS undergoing surgeries from January 2015 through December 2018 were reviewed. Primary endpoint was the rate of ureteral morbidities during and after retroperitoneal liposarcoma resection procedures. Univariate and multivariate analyses determined risk factors associated with ureteral injury (UI) in patients undergoing surgeries. Results: A total of 55 patients of PRLS were included. Fourteen (25.5%) patients underwent PUCP, with 1 UI (7.1%) identified. In 41 patients with no PUCP, 15 (36.6%) exhibited UIs during and post surgeries. There were significant improvements of UIs in group PUCP, compared with patients without PUCP (P < .05). Resection surgeries combined with colectomy and tumor-ureter relationship were 2 risk factors significantly associated to UIs (P < .01). Conclusions: PUCP might be an effective way of preventing UIs in patients with PRLS. It could be suggested especially in patients with ureter encased by tumor or anticipated colectomy during the surgical process.

Real-Time Intraoperative Ureteral Identification in Minimally Invasive Colorectal Surgery: A Systematic Review

Background: Although colorectal surgery (CRS) has currently almost entirely standardized surgical procedures, it can still show pitfalls such as the intraoperative ureteral injury. Intraoperative ureteral identification (IUI) could reduce the ureteral injuries rate but evidence is still lacking. We aimed to analyze the utility and the effectiveness of real-time IUI in minimally invasive CRS. Materials and Methods: A systematic review was performed examining available data on randomized and nonrandomized studies evaluating the utility of intraureteral fluorescence dye (IFD) and lighted ureteral stent (LUS) for intraoperative identification of ureters in CRS, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) standards. Primary endpoint was ureteral injuries rate. Secondary endpoints included acute kidney injury, hematuria, urinary tract infections (UTI), and fluorescence assessment. Results: After literature search, 158 studies have been recorded, 36 studies underwent full-text reviews and 12 studies met inclusion criteria. Overall, out of a total of 822 patients who successfully received IUI, 3 (0.33%) patients experienced ureteral injury. Hematuria was reported in 689 (97.6%) of patients following LUS-guided surgery and in 1 (2%) patient following IFD-guided surgery, although transient in all cases. UTI was reported in 15 (3.3%) LUS-guided resections and in 1 (2%) IFD-guided resections. Acute kidney injury occurred in 23 (2.5%) LUS-guided surgery and 1 (1%) IFD-guided surgery. Conclusions: Real-time ureteral identification techniques could represent a valid solution in complex minimally invasive CRS, safely, with no time consuming and always reproducible by surgeons. Prospective studies will be needed to confirm these findings.

Randomized, Double-Blind, Controlled Study to Evaluate Safety and Pharmacokinetics of Single Ascending Doses of ASP5354, an Investigational Imaging Product, in Healthy Adult Volunteers

Intraoperative ureter identification helps reduce the risk of ureteral injury. Currently, no suitable agents for real‐time ureter visualization are approved. ASP5354 (TK‐1) is a novel indocyanine green derivative. In this first‐in‐human phase 1, double‐blind, sequential ascending‐dose study, urethral catheters were placed in 6 healthy volunteers who were randomized to single‐dose, intravenous ASP5354 0.1 mg (n = 4) or placebo (n = 2). Sequential dose escalations to 0.5‐, 2‐, 8‐, and 24‐mg ASP5354 in new cohorts were contingent upon Dose‐Escalation Committee approval after review of pharmacokinetic (PK) and safety data. Blood and urine samples were collected over 24 hours following dose administration. Objectives were to assess the safety/tolerability and PK of ASP5354. Treatment‐emergent adverse events (TEAEs) were reported in 3 (15%) and 2 (20%) participants in the ASP5354 and placebo groups, respectively. In the former, there were 6 TEAEs (5/6 grade 1‐2). One ASP5354 participant experienced grade 3 pyelonephritis, attributed to the catheter. No TEAEs were related to ASP5354. Mean plasma terminal elimination half‐life ranged from 2.1 to 3.6 hours, with near complete urinary excretion of unchanged ASP5354 within 24 hours after administration. Linear and dose‐proportional PK were observed. These results support further evaluation of ASP5354 at doses up to 24 mg for intraoperative near‐infrared fluorescence ureter visualization.

Ureteral navigation using a fluorescent ureteral catheter during laparoscopic colorectal surgery

BACKGROUND

Ureteral injury is the most common urological complication of pelvic surgery, with a reported incidence during colon resection of 0.3-1.5%. Ureteral stenting is commonly performed preoperatively to prevent ureteral injury. Because tactile sensation is not reliable during laparoscopic surgery, the effect of the ureteral stent is considered limited. Recently, fluorescence imaging has been used in laparoscopic surgery. The Near-Infrared Ray Catheter (NIRC™) fluorescent ureteral catheter (NIRFUC) is a new catheter with built-in NIR fluorescent resin. This pilot study was performed to evaluate the utility of fluorescence ureteral navigation using the NIRFUC during laparoscopic colorectal surgery.

METHODS

We evaluated the intraoperative utility of the NIRFUC and the short-term outcomes in 20 patients treated with colorectal surgery at Kawaguchi Municipal Medical Center between February and July 2020. In all, 18 patients with malignant tumors and 2 patients with benign disease, i.e., a sigmoid colovesical fistula, were included. Ten patients developed preoperative intestinal obstruction. One patient experienced preoperative perforation. Nine patients developed preoperative peritumoral abscesses. Laparoscopic surgery was performed with the VISERA ELITE2 system.

RESULTS

In all cases, the ureters were very clearly identified as fluorescent without the need for dissection. In all cases, only a moment was required to identify the ureter by fluorescence observation. In all cases, R0 resection was performed. The mean surgical duration was 334 min (161-1014), the mean blood loss was 10 ml (1-500), and the mean postoperative hospital stay was 11 days (8-47). There were no cases of ureteral injury.

CONCLUSION

The NIRFUC was very clearly identified as fluorescent in a moment during surgery without dissection around the ureter. Fluorescence ureteral navigation using the NIRFUC may make colorectal surgery easier and facilitate completion of complex minimally invasive surgery, especially during surgery in patients with invasion of the surrounding tissue or a history of pelvic surgery or radiation.

Intraoperative complications during laparoscopic total mesorectal excision

Intraoperative complication during laparoscopic mesorectal excision for rectal cancer is a common complication occurring in 11% to 15% of the cases. They are probably underestimated because not systematically reported. The most frequent intraoperative complications are haemorrhage (3-7%), tumour perforation (1-4%), bowel injury (1-3%), ureter injury (1%), urogenital injury (2%), other organ injury (<1%), and anastomotic complications (1%). The mechanisms, management and prevention of vascular port injury, inferior mesenteric artery bleeding, small bowel and colon perforation, ureteral and urethral injury, pelvic nerve damage, tumour perforation and anastomotic failure are described. This review underlines the necessity to prevent intraoperative complication to avoid operative death and severe side-effects.

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.

[Evidence of indocyanine green fluorescence in robotically assisted colorectal surgery : What is the status?]

BACKGROUND

Indocyanine green (ICG) fluorescence imaging is increasingly being used in various areas of abdominal surgery. The constant improvement in the technology enables easy intraoperative use and progressively influences operative decision-making, also in robotically assisted colorectal surgery.

OBJECTIVE

Summation of current evidence on the use of ICG fluorescence imaging in robotically assisted colorectal surgery.

MATERIAL AND METHODS

The assessment of evidence is based on a comprehensive literature search (PubMed).

RESULTS

First individual studies (feasibility, case matched, prospective cohort, multicenter phase II, single center randomized controlled study/trial) showed a significant reduction in the incidence of anastomotic leakage (AL) after colorectal anastomosis through the use of ICG fluorescence angiography (FA, 9.1% vs. 16.3%; p = 0.04). First feasibility studies demonstrated lymph node detection or navigation as well as ureter visualization.

CONCLUSION

The ICG-FA reliably detects tissue perfusion, quickly and effectively with few side effects. It can influence intraoperative decision-making and reduce AL rates. In addition, patients may be offered more precise tumor therapy via ICG sentinel lymph node (SLN) detection and lateral pelvic lymph node (LPN) mapping and navigation. Iatrogenic lesions, such as ureteral injuries can be sufficiently prevented by appropriate visualization; however, valid data in order to be able to derive standardized operative consequences require further convincing multicenter, randomized controlled trials (mRCT).

Spontaneous Urinoma Without Trauma or Obstruction in a 64-Year-Old Female

A 64-year-old female presented to the ED with severe abdominal pain. Initially it was suspected to be spontaneous aortic rupture or dissection. Contrasted CT imaging studies did not identify aneurysm and dissection, but did identify a concerning, confounding, and curious collection of fluid in the upper right quadrant. Angiography imaging was obtained and identified the origin as the collecting duct of the right kidney. The patient was admitted to the medical service. She was then evaluated by the urology service and they identified this presentation as a urinoma with extravasation of urine, in the absence of trauma or identifiable obstruction.