MINISTRY OF EDUCATION AND TRAININGMINISTRY OF DEFENCE MILITARY MEDICAL UNIVERSITY VU NGOC THANG RESEARCH ON VASCULAR CHARACTERISTICS AND EVALUATE THE RESULTS OF VASCULAR ANASTOMOSIS TECHNIQUES IN LIVI[.]
MINISTRY OF EDUCATION AND TRAININGMINISTRY OF DEFENCE MILITARY MEDICAL UNIVERSITY VU NGOC THANG RESEARCH ON VASCULAR CHARACTERISTICS AND EVALUATE THE RESULTS OF VASCULAR ANASTOMOSIS TECHNIQUES IN LIVING DONOR KIDNEY TRANSPLANTATION AT 103 MILITARY HOSPITAL Speciality: SURGERY Code: 9720104 PhD THESIS ABSTRACT HA NOI– 2023 THIS WORK WAS COMPLETED AT VIETNAM MILITARY MEDICAL UNIVERSITY Scientific Supervisors: Assoc.Prof PhD Nguyen Anh Tuan Assoc.Prof PhD Pham Quang Vinh Reviewer 1: Assoc.Prof PhD Nguyen Quang Reviewer 2: Assoc.Prof PhD Bui Van Lenh Reviewer 3: Assoc.Prof PhD Tran Van Hinh The thesis is presented at the Council of Vietnam Military Medical University at: h(date) / (month)/2023 The thesis can be founded at: Vietnam National Library Library of Military Medical University LIST OF WORKS PUBLISHING RESULTS OF THESIS Vu Ngoc Thang, Le Anh Tuan (2022) Evaluation of some characteristics of transplanted kidney and grafts blood vessels from living donors kidney transplatation at 103 Military Medical Hospital Vietnam Medical Journal; 516 (1): 207-211 Vu Ngoc Thang, Le Anh Tuan (2022) Evaluation of some vascular characteristics of transplanted kidney and results of anastomosis techniques in living donor kidney transplant at 103 Military Medical Hospital Journal of Military Pharmaco-medicine; 47 (5): 236-245 INTRODUCTION The neccessary of the subject Kidney transplantation is a renal replacement therapy for patients with end-stage chronic kidney disease and it is a superior option for patients with end-stage renal failure The quality of transplantation depends primarily on the quality of the blood vessels and anastomosis All researchers have shown that the results of vascular stitching of the transplanted kidney are greatly influenced by the vascular characteristics of the transplanted kidney and the vascular characteristics of the recipient In Vietnam, in the past few years, kidney transplantation has become a routine technique in major organ transplant centres such as 103 Military Hospital, Viet Duc Hospital, Hue Central Hospital, and Cho Ray Hospital Clinically, there are many early and late complications after kidney transplantation related to vascular anastomosis To contribute to perfecting the techniques of suturing and handling when there are changes in both the transplanted kidney's blood vessels and the recipient's pelvic blood vessels, thereby reducing vascular complications and improving the quality of the transplanted kidney, we conducted a study to present the title: “Research on vascular characteristics and evaluate the results of vascular anastomosis techniques in living donor kidney transplantation at 103 Military Hospital” with two objectives: Research on some vascular characteristics of the transplanted kidney, the recipient's pelvic blood vessel in kidney transplant surgery from a living donor at 103 Military Hospital Evaluate the results of vascular anastomosis techniques in kidney transplant surgery from living donors at 103 Military Hospital The new main scientific contributions of the thesis - This is the first research to study the pelvic vascular characteristics of kidney recipients, affecting the vascular anastomosis techniques in kidney transplantation from living donors - From the results of the thesis, methods of treatment have been proposed if there are pelvic arterial abnormalities, or if there are many arteries and veins or transplanted kidney veins are short, comparing results between the two groups anastomosis of the end-to-end anastomosis with the internal iliac artery (IIA) and the end-to-side anastomosis with the external iliac artery (EIA) Since then, there have been new valuable contributions in technology, especially problems in management, suturing, vascular transposition in kidney transplantation, limiting complications, and improving the quality of transplanted kidneys Structure of the thesis The thesis consists of 137 pages (excluding references and appendices), include: introduction (2 pages), overview (35 pages), subjects and methods (23 pages), results (35 pages), discussion (40 pages), conclusion (2 pages) The thesis consists of 43 tables, 10 figures, 30 images and diagram The thesis also used 136 references included in Vietnamsese and in English CHAPTER OVERVIEW 1.1 Kidney anatomy related to kidney transplant 1.1.1 Kidney morphology The normal person has kidneys located behind the peritoneum The kidney consists of two faces, two poles, and two sides The depression in the inner border is called the renal hilum 1.1.2 Kidney size: The Vietnamese kidney volume in men is about 150cm 3, and in women, it's about 136cm3 1.2 Vascular anatomy related to kidney transplantation 1.2.1 Renal vascular anatomical features related to kidney transplantation The renal peduncle is classically described as consisting of an artery and a vein that enter the kidney through the middle part of the hilum The renal vein is located anteriorly more than the artery The right renal artery is about cm longer than the left renal artery The left renal vein is longer than the right *Application in kidney transplant: The renal veins are interconnected, so the pole veins can be ligated without affecting blood flow from the kidney to the inferior vena cava Renal vein length affects the selection of the kidney for transplantation, the placement of the transplanted kidney and the vascular anastomosis technique 1.2.2 Pelvic vascular anatomical features related to kidney transplantation The common iliac artery (CIA): separates from the descending abdominal aorta and divides into the EIA and the IIA Internal iliac artery: during surgery, it is possible to tie the IIA or its branches on one or both sides without any necrosis of the pelvic viscera because it has a branch from the rectum to the inferior colic artery External iliac artery: goes from deep to shallow, has many small branches, and has little abnormal changes, so it is easy to reveal during surgery Pelvic veins: The external iliac vein (EIV) and the internal iliac vein (IIV) receive blood from the pelvic organs, external genitalia, and lower extremities and then drain into the common iliac vein (CIV) and inferior vena cava The iliac veins follow significant branches of the IIA Application in kidney transplant: After separating from the inferior vena cava, the CIV descends posteriorly and into the CIA It divides one or more branches of the IIV and then continues posteriorly to the EIA and runs parallel to the media but remains in the posterior plane of the plane containing the arteries Therefore, surgeons will prefer to transplant the left kidney into the right pelvis and vice-versa 1.3 Techniques of vascular anastomosis in kidney transplantation 1.3.1 Arterial anastomosis 1.3.1.1 There is renal artery - End-to-end anastomosis of the renal artery to the IIA - End-to-side anastomosis of the renal artery to the EIA - End-to-side anastomosis of the renal artery to the CIA 1.3.1.2 There are multiple renal arteries - Two or three renal arteries shaped together in gun barrel style and connect to the EIA by end-to-side anastomosis or to the IIA by end-toend anastomosis - End-to-side anastomosis of a small artery from the poles to the main renal artery - End-to-end anastomosis with the terminal branches of the IIA - End-to-end anastomosis of the accessory artery to the inferior epigastric artery End-to-end anátomosis with IIA or end-to-side anastomosis with EIA - Renal polar artery with a diameter of ≤ mm: can be ligated 1.3.1.3 Anastomosis in the case of atherosclerosis of the aorta of the pelvis - If the IIA is severe atherosclerosis, suture end-to-side anastomosis with the EIA or CIA - EIA is severe atherosclerosis, cut the EIA segment, the defect position will be replaced by an artificial or Homograft circuit, and then the grafted renal artery will be connected to the replacement vessel 1.3.2 Anastomosis renal vein 1.3.2.1 There is a renal vein - End-to-side anastomosis of the renal vein to the EIV - End-to-side anastomosis of the renal vein to the CIV - End-to-side anastomosis of the renal vein to the inferior vena cava 1.3.2.2 There are two or more renal veins or the short renal vein - End-to-side anastomoses with the iliac veins by separate joints - Gun barrel shaping - Short renal vein: lengthen the renal vein by curled, spiral shaping or transposition of blood vessels 1.4 Vascular complications in kidney transplantation 1.4.1 Bleeding: This is a complication that requires early intervention (30-60%) because it can cause loss of kidney transplant function 1.4.2 Arterial stenosis: most common after kidney transplantation 1.4.3 Arterial thrombosis: rare, accounting for 1-2% of cases 1.4.4 Venous thrombosis: rare, usually occurring within the first days after transplantation 1.4.5 Postoperative external iliac artery dissection: rare and should be diagnosed and treated early because it can cause graft loss and lower extremity vessel obstruction CHAPTER SUBJECTS AND METHODS 2.1 Subjects 2.1.1 Subjects Patients with end-stage chronic renal failure who have an indication for kidney transplantation performed a kidney transplant taken from a living donor, and the results of the MSCT film of the kidney taken for transplantation were collected in pairs of kidney donors and recipients at the 103 Military Hospital from December 2019 to December 2020 The process of selecting a kidney transplant pair is carried out regularly according to the regulations of the Ministry of Health of Vietnam 2.1.2 Criteria of exclusion - The patients received a kidney transplant from a living donor at Military Hospital 103 during the study period but it is not enough information and documents for data analysis - The patients did not come to 103 Military Hospital for follow-up due to many reasons (such as transfer of monitoring place, loss of information, etc.) 2.2 Methods 2.2.1 Design of study The research was a prospective, cross-sectional descriptive, with longitudinal follow-up, no control, from December 2019 to December 2020 2.2.2 Sample size Calculated according to the relative reliability formula for a proportion of the descriptive study as follows: n = Z21-α/2 p(1-p) / e2 Choose = 0,05 then Z1-α/2 = 1,96 According to the study of Ahmed Shokeir et al., the rate of vascular complications was 2.9%, so the success rate was 97.1% We take p = 0.03 Substituting into the formula: n= 3.84×0.03×0.97/0.0025 = 44.7 Thus, the minimum number of case studies is 45 2.2.3 Research content 2.2.3.1 The common characteristics of recipients - Age, gender, history, time of dialysis before transplantation, combined diseases - Blood test: urea, creatinine before transplantation 2.3.2 The characteristics of the transplanted kidney, the transplanted kidney vessels, the characteristics of the iliac vessels of the recipients 2.3.2.1 Characteristics of the transplanted kidney and the transplanted kidney vessels * Surgical method and side to take kidney transplant * Characteristics of transplanted kidneys on MSCT: transplanted kidney volume (cm3), combined disease * Characteristics of arterial grafts on MSCT: number, length, diameter, and arterial distribution * Characteristics of venous grafts on MSCT: number, length, diameter * Characteristics of the arterial grafts after washing: arteries and veins: number, length 2.3.2.2 Characteristics of the iliac vessels of kidney recipients * Characteristics of the iliac artery assessed by pre-transplant Doppler ultrasound: - Diameter of common, internal and external iliac arteries - Atherosclerosis status * Observation and assessment during surgery: - Characteristics of the IIAs and EIAs after surgery Evaluation of the degree of atherosclerosis after angioplasty/opening - Characteristics of the EIV walls Is there a blood clot in the blood vessel? 2.3.3 Evaluation the results of vascular anastomosis techniques in living donor kidney transplantation 2.3.3.1 The technical process - Preparation before vascular suture - Perform a kidney transplant: 2.3.3.2 Techniques used in the vascular anastomosis - Position of renal artery anastomosis: * Group one renal artery: + End-to-side anastomosis of the renal artery to the EIA + End-to-end anastomosis of the renal artery to the IIA + End-to-side anastomosis of the renal artery to the CIA * Group of many renal arteries: + Anastomosis of the main renal artery to the IIA, the accessory renal artery to the EIA + anastomosis between the renal artery and the EIA + Shaping the gun barrel by end-to-end anastomosis with the IIA or end-to-side anastomosis with the EIA - Position of renal vein anastomosis: + Anastomosis of the renal vein to the external iliac vein + Anastomosis of the renal vein to the common iliac vein + anastomosis of the renal vein to the external iliac vein - Techniques to manage when the kidney has many arteries, atherosclerotic pelvis, many veins or short renal veins 2.3.4 Criteria for evaluating results of vascular anastomosis techniques 2.3.4.1 Evaluation at the operating table - Evaluation of arterial anastomosis: + Good: the mouth is closed, not dissected, the flow into the kidney is enough for the kidney to stretch and red, and there is no vibration The artery is not twisted, not bent + Not good: have to redo the anastomosis for one of the following reasons: endarterial dissection, irreversible renal ischemia due to twisting or folding of the artery, and narrowing of the anastomosis - Evaluation of venous anastomosis: + Good: closed mouth, swollen, good circulation, no venous aneurysm + Not good: the bleeding venous anastomosis has to be stitched in many places Veins are twisted - Evaluation of renal excretory activity immediately after transplantation - Evaluation of the transplanted kidney at the operating table - Evaluation of complications during surgery - Time to make arterial and venous anastomoses (unit of minutes) - Surgery time 2.3.3.3 Evaluation of results in the postoperative period Post-transplant monitoring indicators during treatment immediately after surgery: the first day, the third day, the fifth day after transplantation and the day of hospital discharge - Monitor kidney function: the amount of urine in the first 24 hours and serum urea and creatinine levels - Evaluation of kidney transplant function related to vascular anastomosis techniques - Evaluation of transplanted kidney function in relation to single and multi-artery group - Doppler ultrasound evaluates the condition of the transplanted kidney: parenchyma, vessels - Early postoperative vascular complications: bleeding, thromboembolism - Postoperative hospital stay - Time of drainage withdrawal - Time of urinary circulation - Evaluation of overall results at discharge: Good, Medium, Poor 2.3.3.4 Evaluation after follow up (re-examination after discharge) All patients after surgery were scheduled to go to 103 Military Hospital for re-examination to evaluate the results of vascular anastomosis by kidney function tests (urea, creatinine in blood), and Doppler ultrasound of the transplanted kidneys: month, >1 to months, >3 to months, >6 months to year, and after year 2.4 Data analysis: 11 3.3.1.1 Location of the transplanted kidney 124 cases of transplanted kidneys were placed in the recipient's right iliac fossa, accounting for 97,6% Three cases of kidney transplants were placed in the recipient's left iliac fossa, accounting for 2,4%, because the first kidney transplant was in the right iliac fossa 3.3.1.2 Techniques on abnormality vessel of the transplanted kidney Multiple renal arteries graft Table 3.18 Management techniques if multiple renal arteries Arterial Total Techniques distribution arteries arteries (%) Gun barrel shaping 9 9(36%) All renal arteries (RA) enter the renal hilum (n=15) The main RA enters the renal hilum (RH), the accessory RA enters the superior pole (n=7) The main RA enters the RH, the accessory RA enters the inferior pole (n=3) separate anastomosis with the EIA separate anastomosis with the IIA, and the EIA separate anastomosis with the IIA, and the EIA + Small vein ligation Small vein ligation Gun barrel shaping + Small vein ligation Suture the accessory RA to be the lateral branch of the main RA Small vein ligation Total 1 (4%) 5 (20%) 2 (8%) 5 (20%) 1 (4%) 1 (4%) 1 (4%) 25 (100%) 22 Multiple renal vein grafts: Table 3.19: separate anastomoses: 1/11 cases (9,1%); Gun barrel shaping 8/11 cases (72,7%); ligation of small vein 1/11 case (9,1%), Gun barrel shaping + Small vein ligation: 1/11 case (9,1%) Management if the renal vein was short: Table 3.20: dissection the renal hilum, renal vein lengthening, change the position of the renal vein posterior to renal artery: 4/39 cases 12 (10,2%) Transposition both of EIAs and EIVs: 32/29 cases (82,1%) Transposition of both the CIV and the CIV to the outside of the EIA: 1/39 case (2,6%) Combination of techniques (1st degree transposition + 3rd degree transposition): 2/39 cases (5,1%) 3.3.1.3 Arterial and venous suture techniques Table 3.21: The end-to-end anastomosis with the IIA: 105/127 cases (82,7%), and the end-to-side anastomosis with the EIA: 22/127 cases (17,3%) Table 3.22: End-to-side anastomosis with the EIV: 126/127 cases (99,2%), end-to-side anastomosis with the CIV: 1/127 case (0,8%) 3.3.2 Evaluation of the results 3.3.2.1 The results at the operating table - Table 3.23 and 3.24, 100% of grafted renal arteries and veins circulate well - Table 3.25, 115/127 of the transplanted kidneys achieved good results (90,6%), but the kidneys were not good in 12/127 cases (9,4%) - Figure 3.3 shows that the majority of patients have urine at the operating table with time ≤ 60 seconds (accounting for 90,6%) There were 12 patients (9,4%) with urine after minute No patient did not have urine at the operating table - Table 3.28 shows that the mean suture time were: group artery is 12,36 ± 1,99 minutes; group of multiple arteries: 21.44 ± 7.07 minutes; the group vein: 12,88 ± 2,45 (mins) and the group of multiple veins: 21,9 ± 4,42 (mins) This difference is statistically significant with p < 0,01 Table 3.29: The mean suture time of the end-to-end anastomosis with the IIA: 13,99 ± 4,83 minutes, and the end-to-end anastomosis with the EIA: 13,75 ± 4,05 minutes The difference between the two techniques was not statistically significant with p > 0,05 - Table 3.30: the average time of surgery: 145,2 ± 23,8 (minutes) 3.3.2.2 The results in the postoperative period - Table 3.31: The average time to drainage withdrawal: 5,9±2,7 days The mean time of hospital stay was 13,5 ± 40,9 days The mean time of urinary circulation was: 8,3±2,9 days - Renal transplanted function: Table 3.33: The average 24-hour urine output gradually decreased from 6496 ± 1447 (ml) on the first day after surgery, and continued to decrease on the 3rd and 5th day after that to 4074 ± 673 (ml) at hospital discharge 13 Table 3.34: The concentration of urea and serum creatinine 24 hours after surgery decreased significantly compared to before surgery This decrease was also significant when compared 24 hours after transplantation and at hospital discharge with p 0,05 Table 3.37: Correlation of Urea and Creatinine concentrations related to arterial suture technique After surgery: The serum creatinine concentration in the group of the end-to-end anastomosis with the IIA was lower than that in the group of the end-to-side anastomosis with the EIA and the serum urea concentration in the group with the anastomosis of the IIA was higher compared with the group connected to the EIA at 24 hours after surgery and hospital discharge, however, the difference in these two groups was not statistically significant p > 0,05 - Doppler ultrasound after surgery: the majority of transplanted kidneys (92,9%) had an RI of 0,75 There were cases (7,1%), and the transplanted kidney had RI > 0,75 - Intraoperative complications and early postoperative complications: no cases of intraoperative complications Vascular complications: no complications related to the vascular anastomosis techniques Bleeding in cases (2,4%) were not related to the stitching techniques - Overall outcome at hospital discharge: Good: 94,5%, Average: 5,5% 3.3.2.3 Results after follow-up (re-examination after discharge) - Mean follow-up time: 10,24 5,25 months - Table 3.38: month after transplantation, the average RI was 0,709 ± 0,06, after 12 months of follow-up, the average RI was 0,696 ± 0,557 Table 3.39 shows that: at the time month, 1-3 months, >6-12 months and 12 months after transplantation, the RI impedance index of anastomosis with the EIA was higher than that to the IIA with p0,05) - There were no cases of renal transplanted complications requiring intervention - Table 4.42: Overall results after follow-up at month, good outcom: 90,5%, and the average: 9,5% After months, good: 90,4%, and average: 9,6% After 12 months of follow-up, the rates were respectively 85,6% and 14,4% CHAPTER DISCUSSION 4.1 General characteristics of recipients Table 3.1: Mean age is 38,12 ± 9,8 years old The oldest patient's age is 66, the lowest is 18 Higher to the study of Tran Ngoc Sinh et al., the mean age is 33,32 ± 8,99 years old but similar to the study of Faruk Ozkul et al., the mean age is 36,9 ± 11,3 The gender ratio of the male patient group accounted for 69,3%, females accounted for 30,7% in the study According to author Nguyen Truong Giang, this ratio is 62/21 According to Maria Gerbase-DeLima et al reported in 2020, men accounted for 57,2% and women accounted for 42,8% Results from figure 3.1, the rate of kidney diseases leading to chronic kidney failure was 38,6%, with unknown cause (when going to the doctor, chronic kidney failure is discovered) 37,8%, different from other country's development of the main cause leading to end-stage chronic kidney failure is type diabetes Table 3.2 found that 16,5% of patients had pre-transplant hepatitis B, similar to Le Thi Thu Hang studied 223 kidney transplant patients at Bach Mai Hospital The rate of patients with hepatitis C was 9,4%, higher than the study of Daniel Cosmin Caragea et al (2018) in the US with a hepatitis C infection rate of 8% Table 3.3: The mean time of dialysis treatment before kidney transplantation in our study was 29,43 ± 45,03 months, lower than that of Mariel Nöhre et al (2018), the average waiting time takes 72 to 84 months to get a kidney transplant 4.2 Characteristics of the transplanted kidney, of the grafted blood vessels, of the recipient's iliac vessels 15 4.2.1 Characteristics of the transplanted kidney, of the grafts blood vessels 4.2.1.1 Characteristics of the transplanted kidney • Surgical method and select side of kidney for transplantation Table 3.5, nephrectomy by transabdominal laparoscopic method: 90/127 cases (70,9%), by open surgery in 37/127 cases (29,1%) In which, 72 cases of kidney transplant were taken from the left side (56,7%), and 55 transplanted kidneys from the right side (43,3%) The results are different from the study of Du Thi Ngoc Thu et al., there were 205/287 cases (71,4%) of transplanted kidneys taken from the left side In a study by Nguyen Thi Anh Huong, the percentage of left kidney being transplanted was 42/54 cases, accounting for 77,8% Choosing side of kidneys for transplantation is the first priority to nephrectomy a kidney with poorer function, so abnormal changes in vascular anatomy are no longer contraindications for kidney transplantation • Volumetric characteristics on MSCT before surgery Table 3.6: The average volume of a donor-kidney male was similar in size on both the left and right sides The transplanted kidney from a donor-kidney female that taken from the right was larger than the left, this difference was not statistically significant with p > 0,05 Fanny Lepeytre et al (2020), a study of 321 transplant recipients, found that a smaller transplanted kidney size compared with the recipient's kidney size was associated with a 1-year higher risk of graft failure compared with a larger kidney transplant similar in size to the recipient 4.2.1.2 Characteristics of the grafts blood vessels • Anatomical features of grafts renal artery • Anatomical features of grafts renal vein 127 cases of transplanted kidney were ordered CT-256 sequences pre-transplant reconstruction, we only noted anatomical changes in the number of grafts blood vessels (arterial and venous grafts), no anatomic changes of other vascular 4.2.2 Characteristics of recipient's pelvic blood vessels 16 • On pre-operative Doppler ultrasound: Table 3.14: On preoperative Doppler ultrasound, the average diameter of the IIA was 6,271,32 (mm), the EIAwas 7.571.15 (mm), the CIA was 9.811.70 (mm) From the measured size, we could compare it with the expected donor renal artery and then calculated the orientation using the technique of suturing the grafted kidney artery with the recipient's iliac artery • Characteristics of arteries in surgery: Table 3.15, we observed that 19/127 cases (14,96%) of arteries (IIAs and EIAs) had abnormalities: yellow endothelium, with atherosclerotic plaque Our atheroma cases are grade to grade III according to Vu Cong Hoe's classification Atherosclerotic status is one of the prognostic factors, assessing long-term outcomes of patients Nakai K et al (2021), atherosclerotic status of the iliac artery is related to the complexity of surgery and the slow effect of transplanted kidney function • Characteristics of veins in surgery: There were cases of thrombus detected in the EIV that were thrombus removed before the suture was performed case of fibrous vein, atrophy, did not guarantee blood flow, so we connected the renal vein to the CIV 4.3 Evaluation of the results of vascular anastomosis techniques in living donor kidney transplantation 4.3.1 Vascular techniques 4.3.1.1 Choosing the location of the transplanted kidney Figure 3.2, 124/127 transplanted kidney patients for the first time and transplanted into the right iliac fossa There were 3/127 cases that transplanted into the left iliac fossa, these were the patients who received the second kidney transplant, the first time the patient had a kidney transplanted into the right iliac fossa This result was similar to the majority of authors 4.3.1.2 Management techniques of transplanted renal vessels • Multiple renal arteries: Table 3.18: all arteries enter the renal hilum (n=15): cases of gun barrel shaping and then connecting to the iliac artery In cases, the main renal artery was connected to the IIA, and the accessory renal artery was connected to the EIA case 17 connecting separate anastomoses with the EIA The main renal artery entered the renal hilum, the accessory renal artery entered the renal pole (n=10): cases that had arteries, were lied on the superior pole artery, connecting the main renal artery with the IIA and the accessory renal artery connecting with the EIA In case, arteries were ligated to the lower pole, shaped like a gun barrel, and connected the renal artery to the IIA case of inferior pole artery anastomosis to the lateral branch of the main renal artery cases of simple pole artery ligation A transplanted kidney has a renal pole artery, most of the authors advocate conservation, but it is possible to ligate the polar arteries with a small diameter (