Consensus on definition and severity grading of lymphatic complications after kidney transplantation

Prevention, incidence, and risk factors of chyle leak after radical nephrectomy and thrombectomy

BACKGROUND

To define the incidence and risk factors of chyle leak (CL) after radical nephrectomy and thrombectomy and to determine the impact of chyle leak on oncological outcomes.

PATIENTS AND METHODS

A total of 445 patients who underwent radical nephrectomy and thrombectomy between January 2014 and January 2023 were included. CL is defined as the drainage of chyle with a triglyceride level greater than 110 mg/dL after oral intake or enteral nutrition. Multivariate logistic regression analysis was performed to identify the risk factors of postoperative (CL). The Kaplan-Meier curves were used to compare overall survival and cancer-specific survival.

RESULTS

44 patients (9.9%) were diagnosed as (CL). All patients developed CL within 6 days after the operation with a median time of 3 days. In multivariate logistic regression analysis, Mayo grade and side were independent patient-related risk factors. In addition, operation approach, operation time, and number of lymph nodes harvested were independent surgery-related risk factors. Between the CL group and the non-CL group, neither overall survival nor cancer-specific survival showed statistical differences.

CONCLUSION

Based on this retrospective study of renal cell carcinoma and tumor thrombus patients in our center, we found that the risk factors were Mayo grade, side, operation approach, operation time, and number of lymph nodes harvested, and the occurrence of CL significantly prolonged hospital stay, but had no effect on long-term oncological outcomes.

Comparison of Bipolar Electrocautery-Based Vascular Sealers with Conventional Ligation in Iliac Vessel Preparation of Renal Transplant Recipients

BACKGROUND

Post-transplant lymphocele is a common complication with a potentially severe course and may require percutaneous drainage or open/percutaneous surgical intervention. Closure of the lymphatics around the iliac vessels is paramount in avoiding lymphocele formation. This study aimed to evaluate the effectiveness of bipolar electrocautery-based vascular sealers (BSD) in the dissection and/or ligation of lymphatic vessels in terms of the development of lymphoceles and postoperative kidney functions in live donor kidney transplants at our center.

METHODS

A total of 63 patients who underwent kidney transplantation (KTx) between January and December 2021 were included in the study. Data, including postoperative creatinine values and postoperative ultrasonography follow-up, were recorded. Thirty-seven patients who were operated on using conventional ligation for iliac vessel preparation were included in group 1. Twenty-six patients treated using BSD for iliac vessel preparation were included in group 2. Statistical analysis was performed to compare these groups. This study complied with The Helsinki Congress and The Declaration of Istanbul.

RESULTS

There was no significant difference between the groups in terms of postoperative first-week creatinine values (1.176 mg/dL vs 1.203 mg/dL), first-month creatinine values (1.061 mg/dL vs 1.091 mg/dL), first-week collection volume (33.240 mL vs 33.430 mL), and third-month collection volume (23.120 mL vs 23.430 mL) (P > .05).

CONCLUSIONS

In KTx surgery, BSD is as safe as and faster than conventional ligation in preparation of the recipient's iliac vessels.

Incidence, Risk Factors, and Management of Incisional Hernias After Kidney Transplant: A 20-Year Single Center Experience

BACKGROUND

Incisional hernias (IH) constitute a complication after kidney transplant (KT). Patients may be particularly at risk because of comorbidities and immunosuppression. The study aim was to assess the incidence, risk factors, and treatment of IH in patients undergoing KT.

METHODS

This retrospective cohort study included consecutive patients who underwent KT between January 1998 and December 2018. Patient demographics, comorbidities, perioperative parameters, and IH repair characteristics were assessed. Postoperative outcomes included morbidity, mortality, need for reoperation, and length of stay (LOS). Patients who developed IH were compared with those who did not develop one.

RESULTS

Forty-seven patients (6.4%) developed an IH after a median delay of 14 months (IQR, 6-52 months) in 737 KTs. On uni- and multivariate analyses, body mass index (odds ratio [OR], 1.080; P = .020), pulmonary diseases (OR, 2.415; P = .012), postoperative lymphoceles (OR, 2.362; P = .018), and LOS (OR, 1.013; P = .044) were independent risk factors. Thirty-eight patients (81%) underwent operative IH repair, and 37 (97%) were treated with a mesh. The median LOS was 8 days (IQR, 6-11 days). Three patients (8%) developed surgical site infections, and 2 patients (5%) presented hematomas requiring surgical revision. After IH repair, 3 patients (8%) had a recurrence.

CONCLUSIONS

The incidence of IH after KT seems rather low. Overweight, pulmonary comorbidities, lymphoceles, and LOS were identified as independent risk factors. Strategies focusing on the modifiable patient-related risk factors and early detection and treatment of lymphoceles may help to decrease the risk of IH formation after KT.

Ureterovesical Anastomosis Complications in Kidney Transplantation: Definition, Risk Factor Analysis, and Prediction by Quantitative Fluorescence Angiography with Indocyanine Green

Ureteral stenosis and urinary leakage are relevant problems after kidney transplantation. A standardized definition of ureterovesical anastomosis complications after kidney transplantation has not yet been established. This study was designed to demonstrate the predictive power of quantitative indocyanine green (ICG) fluorescence angiography. This bicentric historic cohort study, conducted between November 2015 and December 2019, included 196 kidney transplantations. The associations between quantitative perfusion parameters of near-infrared fluorescence angiography with ICG and the occurrence of different grades of ureterovesical anastomosis complications in the context of donor, recipient, periprocedural, and postoperative characteristics were evaluated. Post-transplant ureterovesical anastomosis complications occurred in 18%. Complications were defined and graded into three categories. They were associated with the time on dialysis (p = 0.0025), the type of donation (p = 0.0404), and the number of postoperative dialysis sessions (p = 0.0173). Median ICG ingress at the proximal ureteral third was 14.00 (5.00–33.00) AU in patients with and 23.50 (4.00–117.00) AU in patients without complications (p = 0.0001, cutoff: 16 AU, sensitivity 70%, specificity 70%, AUC = 0.725, p = 0.0011). The proposed definition and grading of post-transplant ureterovesical anastomosis complications is intended to enable valid comparisons between studies. ICG Fluorescence angiography allows intraoperative quantitative assessment of ureteral microperfusion during kidney transplantation and is able to predict the incidence of ureterovesical anastomosis complications. Registration number: NCT-02775838.

Lymphatic Tissue and Organ Engineering for In Vitro Modeling and In Vivo Regeneration

The lymphatic system has an important role in maintaining fluid homeostasis and transporting immune cells and biomolecules, such as dietary fat, metabolic products, and antigens in different organs and tissues. Therefore, impaired lymphatic vessel function and/or lymphatic vessel deficiency can lead to numerous human diseases. The discovery of lymphatic endothelial markers and prolymphangiogenic growth factors, along with a growing number of in vitro and in vivo models and technologies has expedited research in lymphatic tissue and organ engineering, advancing therapeutic strategies. In this article, we describe lymphatic tissue and organ engineering in two- and three-dimensional culture systems and recently developed microfluidics and organ-on-a-chip systems in vitro. Next, we discuss advances in lymphatic tissue and organ engineering in vivo, focusing on biomaterial and scaffold engineering and their applications for lymphatic vessels and lymphoid organ regeneration. Last, we provide expert perspective and prospects in the field of lymphatic tissue engineering.

A Novel Technique Using Fluorescent Ureteral Catheter and Flexible Ureteroscope for Safe Laparoscopic Fenestration of Lymphocele after Kidney Transplantation

Laparoscopic fenestration of a postrenal transplant lymphocele is associated with a risk of renal hilar vessel and ureteral injury. Consequently, determination of the incision line is difficult. We describe a case of a 73-year-old man with postrenal transplant lymphocele who underwent a laparoscopic fenestration. We report a surgical video containing a new technique of laparoscopic fenestration using a fluorescent ureteral catheter in combination with a flexible ureteroscope. The combination of a fluorescent ureteral catheter and flexible ureteroscope during surgery enabled us to determine the incision line safely and accurately. Intraoperative real-time visualization of the lymphocele and ureter using a fluorescent ureteral catheter and a flexible ureteroscope is safer than conventional methods for laparoscopic fenestration. To the best of our knowledge, this is the first report of this novel technique.

Prophylactic Peritoneal Fenestration during Kidney Transplantation Can Reduce the Type C Lymphocele Formation

Lymphocele is a common complication following kidney transplantation (KTx). We aimed to evaluate the preventive effect of peritoneal fenestration during KTx in reducing lymphocele. From January 2001, the data of all KTx were prospectively gathered in our digital data bank. From 2008, preventive peritoneal fenestration was performed as a routine procedure for all patients with KTx. Between 2001 and 2008, 579 KTx were performed without preventive peritoneal fenestration. To compare the results between with and without peritoneal fenestration, the same number of patients after 2008 (579 patients) was included in this study. The pre-, intra-, and postoperative data of the patients in these two groups were analyzed and compared, especially regarding the postoperative different types of lymphocele formation. The mean recipient age was 52.6 ± 13.8, and 33.7% of the patients were female. Type C lymphocele was significantly lower in the group with preventive fenestration (5.3% vs. 8.8%, p = 0.014 for 31/579 vs. 51/579). Peritoneal dialysis and implantation of the kidney in the left fossa were independently associated with a higher rate of type C lymphocele (OR 2.842, 95% CI 1.354–5.967, p = 0.006 and OR 3.614, 95% CI 1.215–10.747, p = 0.021, respectively). The results of this study showed that intraoperative preventive peritoneal fenestration could significantly reduce type C lymphocele.

Validating Consensus-Defined Severity Grading of Lymphatic Complications after Kidney Transplant

Lymphatic complications after kidney transplantation (KTx) are associated with morbidities such as impaired wound healing, thrombosis, and organ failure. Recently, a consensus regarding the definition and severity grading of lymphoceles has been suggested. The aim of the present study was to validate this classification method. All adult patients who underwent KTx between December 2011 and September 2016 in our department were evaluated regarding lymphoceles that were diagnosed within 6 months after KTx based on the recent definition. Patients with lymphoceles were categorized according to the classification criteria, and clinical outcomes were compared between the groups. In our department, a total of 587 patients underwent KTx between 2011 and 2016. Lymphoceles were detected after KTx in 90 patients (15.3%). Among these patients, 24 (26.6%) had grade A lymphoceles, 14 (15.6%) had grade B, and 52 (57.8%) had grade C. The median duration times of intermediate care (IMC) and hospital stay were significantly higher among patients with grade C lymphoceles than they were among patients with grade A and B lymphoceles. Significantly more patients with grade C lymphoceles were readmitted to the hospital for treatment. The recently published definition and severity grading of lymphoceles after KTx is an easy-to-use and valid classification system, which may facilitate the comparison of results from different studies on lymphoceles after KTx.

Bipolar vessel sealing system versus silk ligation of lymphatic vessels in renal transplant recipient lymphatic complications: a randomized controlled trial

PURPOSE

This study was aimed to compare lymphatic complications of bipolar vessel sealing system with silk ligation of lymphatic vessels among renal transplant recipients.

METHODS

This was a prospective randomized controlled trial done among 68 patients undergoing renal transplantation in Tribhuvan University Teaching Hospital. They were randomly assigned to either silk ligation or Enseal bipolar vessel sealing lymphatic dissection. Postoperative drain volume and duration of drain placement were measured in all patients. Ultrasound was used to find lymphocele formation in six and 12 weeks.

RESULTS

Total of 30 patients in silk ligation group and 28 patients in bipolar vessel sealing group were analyzed. The baseline characteristics of the patients in each group were similar. Overall, lymphatic complications (either lymphorrhea or lymphocele formation) were in 16 cases (27.58%), 7 (25%) in the bipolar group, and 9 (30%) in the silk ligation group (p = 0.67). A total of 13 patients (22.41%) had lymphorrhea, 6 (21.4%) patients in the bipolar group, and 7 (23.3%) patients in the silk ligation group. Median drain volume was 415 ml (Q1 275 ml, Q3 675 ml) in the bipolar group and 542 ml (Q1 290, Q3 775) in silk group (p = 0.72). Median drain removal day was 5 in each bipolar and silk group with Q1 and Q3 being 5 days in each arm (p = 0.95). A total of five patients (8.62%) developed symptomatic lymphocele, two (7.1%) in the bipolar group, and three (10%) in the silk ligation group, but the difference was not statistically significant. In univariate analysis, double renal arteries in the donor's kidney (p = 0.03) and graft rejection (p = 0.04) were risk factors for the development of lymphatic complications. However, in multivariable analysis, these factors were not statistically significant.

CONCLUSIONS

This study did not find any significant differences in lymphatic complications between bipolar vessel sealing system and silk ligation. However, large sample multi-centric studies should be done to add evidences on lymphatic complications differences between these two techniques.

TRIAL REGISTRATION NUMBER

UMIN000039354, Date of registration-2020, Feb 01.

Efficacy of Lymphatic Sealing Using the LigaSure in Kidney Transplantation: A Pilot Study

BACKGROUND

Iliac vessel lymphatic ligation is critical in kidney transplantation, because it is associated with the occurrence of lymphocele. Lymphocele can also affect the renal graft. This study aimed to evaluate the efficacy of lymphatic sealing using LigaSure (an electrothermal bipolar sealing device) in kidney transplantation as compared with conventional silk-tie ligation.

METHODS

This retrospective study included 100 consecutive patients from a prospectively registered database who underwent kidney transplantation at Seoul St. Mary's Hospital, South Korea, between December 1, 2019 and November 12, 2020. Comorbidities, primary renal disease, transplantation variables, surgical variables, and posttransplantation outcomes were compared between conventional and LigaSure lymphatic ligations. Subgroup analyses were performed by anastomosis pattern.

RESULTS

The mean age of patients was 47.4 ± 12.40 (range, 24-73) years. The LigaSure and conventional groups comprised 50 (50%) patients. Hypertension history, number of anastomosed renal arteries, and anastomosis patterns differed significantly between groups (P < .05). No significant difference was found in postoperative outcomes. In the subgroup analysis, greater drain volume was found at postoperative day 1 in the end-to-end internal iliac artery-renal artery anastomosis group (P = .001) because the internal iliac artery dissection results in longer lymphatic ligation. Nevertheless, no differences in drain removal time (P = .528) or lymphocele incidence were found between subgroups.

CONCLUSION

LigaSure is expected to benefit from surgery time and will be identified in subsequent studies. LigaSure can be safely and comfortably used for iliac lymphatic ligation in kidney transplantation. In conclusion, LigaSure lymphatic ligation is superior to conventional lymphatic ligation in kidney transplantation.

Minimal-invasive management of urological complications after kidney transplantation

Kidney transplantation represents the gold standard treatment option for patients with end-stage renal disease. Improvements in surgical technique and pharmacologic treatment have continuously prolonged allograft survival in recent years. However, urological complications are frequently observed, leading to both postoperative morbidity and putative deterioration of allograft function. While open redo surgery in these patients is often accompanied by elevated surgical risk, endoscopic management of urological complications is an alternative, minimal-invasive option. In the present article, we reviewed the literature on relevant urological postoperative complications after kidney transplantation and describe preventive approaches during the pre-transplantation assessment and their management using minimal-invasive approaches.