MINISTRY OF EDUCATION AND TRAININGMINISTRY OF DEFENCE
MILITARY MEDICAL UNIVERSITY
===========
DO NGOC SON
RESEARCH ON TECHNICAL CHARACTERISTICS
AND RESULTS OF LIVINGDONOR KIDNEY
TRANSPLANTION AT VIETDUC UNIVERSITY
HOSPITAL
Speciality: SURGERY
Code: 9720104
PhD. THESIS ABSTRACT
HA NOI– 2019
THIS WORK WAS COMPLETED
AT VIETNAM MILITARY MEDICAL UNIVERSITY
Scientific Supervisors:
1. Assoc.Prof. PhD. Nguyen Tien Quyet
2. Assoc.Prof. PhD. Hoang Long
Reviewer 1: Prof. PhD. Nguyen Thanh Liem
Reviewer 2: Assoc.Prof. PhD. Le Viet Thang
Reviewer 3: Assoc.Prof. PhD. Le Dinh Khanh
The thesis is presented at the Council of Vietnam Military Medical
University at: h(date) / (month)/2019
The thesis can be founded at:
1. Vietnam National Library
2. Library of Military Medical University
3. Library of Viet Duc University Hospital
LIST OF WORKS PUBLISHING RESULTS OF THESIS
1. Do Ngoc Son, Hoang Long, Vu Nguyen Khai Ca and
Nguyen Tien Quyet (2018). Ureterovesical reimplantation in
renal transplantation from living donor at Viet Duc Hospital.
Vietnam Journal of Medicine, Issue 2 November, 3336.
2. Do Ngoc Son, Nguyen Tien Quyet, Hoang Long (2018).
Surgical results of livingdonor kidney transplantation of Viet
Duc hospital. Vietnam Journal of Medicine, Issue 2 November,
14.
3. Do Ngoc Son, Hoang Long, Vu Nguyen Khai Ca và
Nguyen Tien Quyet (2018). Surgical results of ureterovesical
reimplantation in renal transplantation from living donor at Viet
Duc Hospital. Journal of Military PharmacoMedicine,Vol
43,N0 9, December, 158162.
4
INTRODUCTION
1. The neccessary of the subject
Renal transplantation from living donors has become routine
surgery in many hospitals across the country with the technical
process agreed by the Ministry of Health since 2006. However,no
studies have yet evaluated kidney transplant results in case of the
renal artery anastomosed endtoside with recipient’s iliac artery
(external or common iliac).
In addition, transplant centers tend to perform laparoscopic donor
nephrectomy, so the number of donor kidney with short vein is
increasing (especially the right kidney). A simple solution can be
used when kidney transplant in in the right iliac fossa, even when the
short vein, reducing the rate of renal transplant vascular plasty without increasing complications is inverted kidney transplant. The
reports all over the world recognize the advantages of this technique, but in Vietnam there are no topics to study the “inverted kidney transplant” in kidney transplantation.
To evaluated the result of living donor kidney transplant with endtoside arteries anastomosis and applying inverted kidney transplant technique in right iliac fossa, we performed the study: “Research on the technical characteristics and the results of livingdonors kidney transplant at Viet Duc University Hospital”,
with objectives:
1. Research on technical characteristics of kidney transplant
surgery from living donor at VietDuc University Hospital.
2. Evaluate the result of livingdonor kidney transplant at VietDuc
University Hospital.
5
2. The new main scientific contributions of the thesis
The thesis is the first study which evaluate the result of living donor kidney transplant with inverted kidney transplant technique and endtoside arteries anastomosis between renal artery and recipient’s iliac artery (external or common iliac).
From the result of this study may open a new direction for kidney transplantation techniques: it is possible to apply inverted kidney transplant in case right kidney transplants in the right iliac fossa or left kidney transplants in the left iliac fossa . 3. Structure of the thesis
The thesis consists of 145 pages (introduction 3 pages, overview 38 pages, subjects and methods 25 pages, results 38 pages, dicussion 38 pages, Conclusion 2 pages, and Recommendation 1 page); with 42 tables, 28 images, 22 graphs and 17 figure. The thesis also used 130 references, 31 refs. in Vietnamsese and 99 refs. in English.
CHAPTER 1 OVERVIEW
1.1. The brief history of kidney transplant
On April 23, 1954, in Boston, Joseph E. Murray et al. successfully performed kidney transplants foridentical twins and survived for 8 years. After that, kidney transplantation has been widely developed worldwide.
In Vietnam, the first successfully kidney transplant from a living donor was conducted in 1992 at 103 Military Hospital. VietDuc Hospital conducted kidney transplants from living donor since 2000 and now this operation becomes routine surgery. 1.2. Anatomy related to kidney transplant 1.2.1. Renal anatomy related to kidney transplant
A kidney consists of 2 planes, 2 poles, 2 edges and a hilum; with
12cm in length, 6 cm in width and 3cm thickness on average.
6
Normally, there are 1 artery, 1 vein in renal hilum. The renal veinis located in front of the artery. A kidney may have 1 or more arteries or veins. The veins are interlocked, so they can be ligated at the root without serious problems. The length of renal vein affects the choice of right of left donor nephrectomy, graft position and suture techniques of the authors worldwide.
The ureter drains urine from the kidney to the bladder. The
ureter is only supllied by branch of renal artery. 1.2.2. Iliac vessels
The common iliac artery separates from the abdominal aorta to
the lower part, dividing into the external and internal iliac arteries.
The internal iliac artery may beligated the whole or its branches
on one or both sides, but the pelvic organs do not become necrotic.
External iliac arteries go from deep to shallow and often do not
have large lateral branches, so easy disclosure.
The right common iliac vein separates from inferior vena cava, goes down and lies behind and internal of common iliac artery. It divides into 1 or more internal iliac veins and goes parallel posteriorly of external iliac artery. Therefore, surgeons often prefer to choose a left graft into the right pelvis and vice versa. 1.3. Kidney transplant techniques 1.3.1. The kidney transpant incision and the natural compatibility
of vessels in graft position
1.3.1.1. The incision
Gibson incision often used in kidney transplantation.
1.3.1.2. Graft placement
There are 3 trends: taking the kidneys on any side, then grafting into the opposite iliac fossa, or grafting into the same iliac fossa side, or grafting all into the right iliac fossa. Some authors choose a low
7
back position to place a graft in kidney transplantation for children or for the third transplant. 1.3.2. Kidney transplantation technique 1.3.2.1. Graft preparation
Vascular plasty for graft arteries or veins in case of the variable number of graft vessel: making 2 arteries into 1 main artery ‘gun type’ when they are equivalent in diameter, or plant the pole artery into main artery. It is possible to leave 2 arteries without plasty. Grafts with many veins also treat similarly many arteries.
Graft ureter assessment: vessels, length and integrity of graft ureter.
1.3.2.2. Steps of procedure
Step 1: General anesthesia Step 2: Skin incision, prepare graft hole Step 3: Graft placement Step 4: Vascular anastomosis
o Renal vein: endtoside with external or common iliac vein o Renal artery: endtoside with external or common iliac artery Renal with 2 arteries:
Making 2 endtoside anastomoses to external iliac artery; or 1 anastomosis with external iliac artery, 1 anastomosis with common iliac artery.
Making 1 endtoend anastomosis to internal iliac artery, and 1 endtoside anastomosis with external or common iliac artery. Step 5: Loosening vascular clamp, evaluating the graft, vascular anastomoses, ureter. Step 6: Reimplanting the graft ureter into bladder wall
+ Lich – Gregoir procedure + Politano – Leadbetter procedure + Others techniques. 1.4. Complications of kidney transplant
8
1.4.1. Intraoperative complications
Intraoperative bledding: identify the reason and resolve. Curvature, or kinking of anastomoses: resuture.
1.4.2. Surgical complications of kidney transplant 1.4.2.1. Vascular complications
Bledding, perigraft hematomas. Vascular thromboses: the first graftloss reason. + Renal vein thrombosis: Renal vein occlusion due to thrombosis soon after transplantation is rarely seen and often involves technical problems.
+ Spontaneous arterial thrombosis is rare. Technically, there are three main causes of arterial thrombosis: arterial injuries when nephrectomy, injuries of vascular endothelium, or kinking/folding graft artery.
Arterial stenosis:the most common postoperative complication. Chyle leakage, orchyle cyst: common in obesity, diabetes and
wound infection. 1.4.2.2. Urologic complications
Urine leakage: technical failure or ureteral necrosis. Utereal obstruction or stenosis: due to extruding from outside,
lack of blood support, or ureterovesical junction stricture.
Ureteovesical reflux: the most common risk causing recurrent
urinary tract infection. 1.4.3. Medical complications
Internal medically, many factors can affect graft function. Hyperacute graft rejection, acute rejection are the leading causes of graft function decline in early stage. Exclusion should be performed due to surgical techniques to provide timely and appropriate treatment. Graft biopsy is the gold standard to determine the medical condition.
9
1.4.4. Some factors affect longterm graft function
Some studies have reported: factors such as HLA match, donor age, duration of graft cold ischemia are factors that have been confirmed to affect the results of kidney transplant.
Obesity increases the rate of delayedgraft function causing patients to need dialysis in the first week after surgery, wound infection and prolonged hospital stay.
CHAPTER 2 SUBJECTSANDMETHODS
2.1. Subjects 2.1.1. Subjects
Including 101 patient with endstage kidney diseases, who were indicated for kidney transplant from livingdonor at VietDuc University Hospital, from January 2011 to December 2013. 2.1.2. Criteria of exclusion
The transplant operation is not in duration of study. It is not enough following time. It is not enough information and documents to data analysis.
2.2. Methods 2.2.1. Design of study
The descriptive longitudinal serialcases study. The subjects were divided into two groups: inverted kidney
transplant group and non inverted kidney transplant group.
Perform inverted kidney transplant in case: + Right kidney donor transplants into the right iliac fossa + Left kidney donor have abnormalities in front of the arteries and renal vein, making it difficult to anastomosis renal veins to external iliac vein and kidney arteris to external or common iliac artery. 2.2.2. Sample size
Nonprobability samplign (101 cases).
10
2.2.3. Research content
The data was collected from couples of donor and recipientwho were registered for kidney transplantation at Viet Duc hospital, with all the selection criteria prescribed by the Ministry of Health and according to the preset dossier format. 2.2.3.1. The common characteristics of recipients
Demographic, chronic diseases (diabetes, hypertension…),
viral infetion (Hepatitis B/C virus…).
Blood test: cell counts, biochemical analysis (ure, creatinin). Cystography,bladder volume calculation. Time of dialysis until before surgery. Blood group matching, HLA matching.
2.2.3.2. Graft characteristics
* Side of graft: right or left. Selection of donorgraft based on assessment of renal function on renal scintigraphy given. They all chose to take kidneys with less function to transplant, keeping better kidneys for donor.
* Graft characteristics after irrigation. The grafts after being taken from the donor irrigated with 1 litre of cold Custodiol solution. After irrigating, record the characteristics: shape, artery, vein and ureter. 2.2.3.3. Evaluation of graft after irrigation
Good: Kidney is milk white, quite firmly; there is no injuries of artery or vein, integrity of surrounding fat and vessels of ureter. Not good: There are injuries: lanceration, contusion or
hematoma of graft parenchymal, artery or vein.
2.2.3.4. Process of kidney transplant Patientposition: supine. Graft placement: right iliac fossa. Skin incision: Gibson incision.
11
Presenting right iliac fossa, assessing recipient’s vessels: conventional anatomy or variant, number, size…; taking care not to damage lymphatic vessel along with iliac vessels (assesment of all: common/external/internal iliac vessel).
Graft placement: . Right kidney: Upside down (inverted kidney transplant). . Left kidney: non inverted kidney transplant. Vessels suturing: suture vein first, and the artery. Graft revascularization: loosening of vein clamp first and then
artery clamp.
Ureter reimplantation: we use modified LichGregoir
extravesical procedure with JJstent.
Evaluate of graft condition after revascularizing: o Good: Renal vessels are distended, no stricture, no zigzag, no
bleeding at anastomoses. Kidney is firmly, pink and excreting the urine.
o Not good: + Vessels anastomoses are not distended, or bleeding, or
stricture due to kinking or folding. + Kidney is soft, purple. + Kidney is firmly, pink but there are some areas with
contusion, ischemia, subcapsule hematomas…
+ Kidney is not firmly. + There is no excretion of urine, or slow down. Evaluate of renal function after revascularizing, blood support
and excretion of urine:
+ Kidney excretes urine during 60 sec (1 minute) after revascularizing:
early excretion.
+ Kidney excretes urine in 1 minute or moreafter revascularizing: late
excretion.
+ No urine until the operation is done.
12
Intraoperative complications: + Bleeding: from vessels of right iliac fossa, suturing. + Vessel thromboses: causing graft vessels obstruction; retaking
out the graft, thrombectomy, reirrigating and resuturing the vessels.
Treatment and followup. + Immunosuppresive agents. + Followup. Followup just after surgery, day 1, day 3 and discharge. + General conditionand wound. + Urine 24 hour, time of catheterization. + Drainage: output 24h and time of drainage. + Blood test:ure (mmol/l) andcreatinin (µmol/l) + Doppler ultrasonud, evaluate some graft characteristics: vascularization, artery, vein, RI index, pelvis and ureter, fluid surrounding graft in 2 or 3 day after surgery.
+ Hospital stay is counted from day of transplant to discharge. Criteria of discharge: general condition is stable,healed wound, normal urination, renal function is normal or towards to normal according to ure and creatinin index. Reexamine 1 per week.
2.2.3.5. Longterm followup (after discharge)
JJstent is removed 1 month after surgery. Reexamine: renal function (ure, creatinin), graft ultrasound 13 612 months after surgery. It is possible to take Doppler ultrasound for graft vascular, multislide CTScan, graft biopsy… in selected cases with doubt of complications.
2.3. Data analysis
Data is analyzed by STATA 12.0 software.
2.4. Ethics in research
13
We strictly adhere to the law on organ transplants from the National Assembly, the Government and the Ministry of Health. The research proposal was approved by the Military Medical Science Council. The technical process of transplantation is approved by Viet Duc Hospital.
CHAPTER 3 RESULTS
3.1. General characteristics
In 101 patients underwent living donor kidney transplant: 57/101 patients with inverted kidney transplant and 44/101 patients with non inverted kidney transplant. Mean age was 36.9 ± 11.0 years old. Male to female ratio was 2/1 with 68.3% males and 31.7% females. There was 37/101 patients (36.6%) with endstage renal failure due to renal diseases. Comorbidity was hypertension (44.6%). Time of hemodialysis prior to transplant was 2.2 ± 2.0 years, and there was no difference between inverted kidney transplant group and non inverted kidney transplant group.
The rate of living donors who were not family member was 79.2%; 96% in same blood type in which 49.5% O blood type. HLA compatibility: 75.2% in class I, 55.4% in class II, 49.5% compatibility in both 2 class. BMI index was 68.3%. Recipient vesical capacity was 171.5 ± 69.5 ml (normal range ≥ 100ml in 83.2% pts, low capacity<100ml in 16.8%).
3.2. Technical aspects
Graph 3.4: The rate of right donor nephectomy was higher than
left donor nephectomy (56.4% and 43.6%, respectively). 3.2.1. Size of graft
Table 3.11. Mean length of graft in inverted kidney transplant group and noninverted kidney transplant group were 10.9 ± 0.7 (cm)
14
and 10.9 ± 0.8 (cm), respectively. There was no difference in length, width and thickness of graft between 2 groups (p>0.05). 3.2.2. Graft ureter andvascular characteristics
Table 3.12 and 3.13: 3.7% grafts with 2 veins and 17.8% grafts with 2 arteries, no difference between inverted kidney transplant group and noninverted kidney transplant group (p>0.05)
Table 3.14: the length of graft vein in inverted kidneys was
shorter than in noninverted group significantly (p<0.001).
Table 3.16: All graft ureters were long enough to reimplante. There was no difference in length and diameter of graft ureter between inverted kidney transplant group and noninverted kidney transplant group (p>0.05). 3.2.3. Assessment of graft after irrigation
Table 3.16: good grafts were dominated with 96%. There were 4 graft not in good condition, but they were not so bad that could not be transplanted. Also there was no difference in graft condition (good or not good) between inverted kidney transplant group and non inverted kidney transplant group (p > 0.05). 3.2.3. Additional vascular plastic techniques after irrigation
Table 3.17: grafts with 2 arteries, no plasty in 13/18 recipients (72.2%), vascularreconstruction into 1 trunk (‘pantalon type’) in 5/18 recipients (27.8%). There was no venous reconstruction.
Table 3.18: We did not use vascular disposition technique in 91.1% of cases, ligation of branchs of internal iliac vein in 7 cases (6.9%), vascular disposition in 1 case (1%), 1 case was underwent both 2 techniques.
3.3. Surgical results of living donor kidney transplant 3.3.1. Comments on incision, graft placement and vascular anastomosis.
15
Table 3.19 and 3.20: Right Gibson incision was used in 100% of cases, also the grafts were placed in right iliac fossa. There were 57/101 patients (56.4%) with inverted kidney transplant and 44/101 patients with noninverted kidney transplant (43.6%); 98.2% inverted kidney transplant was the right kidney.
Table 3.21: in grafts with 1 vein, the endtoside anastomosis with recipient’s external iliac vein was made in 97.9%, and with common external iliac vein in 2.1%. In all 4 grafts with 2 veins, the separated venous anastomoses was made with external iliac vein.
Table 3.22: In 96.4% grafts with 1 artery, the endtoside anastomoses were made with recipient’s external iliac artery; the rates in inverted kidney transplant and noninverted kidney transplant were 97.4% and 95.6%, respectively. In 83.3% grafts with 2 arteries, 2 separated anastomoses were made with external iliac artery; in the rest 16.7%, 1 anastomosis was made with external iliac artery and another with common iliac artery.
Table 3.23 and 3.24: Mean time of veinous anastomosis was 14.9 ± 5.5 mins and 14.4 ± 5.1 mins for arterial anastomosis. There was no statistical difference in the time for arterial or venous anastomosis between inverted kidney transplant group and non inverted kidney transplant group (p > 0.05).
Table 3.25: Mean time of ureter reimplantation was 24 ±7.9 mins, and there was no statistical difference between inverted and noninverted kidney transplant, as well as no correlation with bladder capacity. 3.3.2. Results of revascularization
Table 3.26 and 3.27: Nearly all the graft’s artery and vein were in good condition after revascularization (99%). Therefore, inverting kidney did not impact on graft blood circulation.
Table 3.28: 100% graft’s ureters werein good condition. Table 3.29: Warm ischemia time in grafts with 2 arteries or 2 veins were longer significantly than in grafts with 1 artery or 1 vein,
16
with p = 0.0025 and p = 0.002, respectively. But there was no difference in warm ischemia time between inverted and noninverted kidney transplant with p = 0.379 > 0.05.
Table 3.30: there was a statistical difference in cold ischemia time between grafts with 1 artery and 2 arteries group (p = 0.0094); but it was equivalent in 2 groups: grafts with 1 vein and 2 veins (p = 0.2066). There was no difference in cold ischemia time between inverted and noninverted kidney transplant with p = 0.3048.
Table 3.31: Mean duration of transplant surgery was 148 ± 30 mins and there was no difference between inverted and noninverted kidney transplant with p > 0.05. Mean operation time of grafts with 2 arteries group was statistical longer than of grafts with 1 artery (p = 0.0085 < 0.05)
3.4. Graft followup 3.4.1. Early stage
Graph 3.6 and table 3.32: After revascularized, all the grafts excreted urine in time of surgery, in which 90/101 cases (89,1%) had urine excretion under 1 mins, 11/101 cases (10,9%) had urine excretion slower 1 mins. There was no difference in urine excretion time between inverted and noninverted kidney transplant with p = 0.136 > 0.05.
Graph 3.7: Intraoperative complications ocurred in 3/101 cases
(acounted for 3%)
Table 3.33. 99/101 cases (98%) with graft in good condition and no difference in graft condition between inverted and noninverted kidney transplant (p > 0.05). 3.4.2. Some indexes inpostoperative period
Table 3.34, Graph 3.8: total amount of urine in first 24 hours was 14.1 ± 4.2 litre, andthere was no difference between inverted and
17
noninverted kidney transplant (p > 0.05). Urine volume decreased gradually until discharge.
Table 3.35, 3.37, Graph 3.9 and 3.10: ure and creatinine concentration decreased gradually from the first day after surgery to discharge, and there was no difference between inverted and non inverted kidney transplant. However, at the time of discharge, 4 grafts were not in good condition (4%), in which 1 graft loss due to rejection.
Graph 3.11: Doppler ultrasound revealed the normal vascular circulationin all grafts (100%); RI of graft’s parenchymal was in normal range in 94,1%.
Table 3.38: time of drainage operation field was 7.6 ± 2.2 days, time of urethral catheter was 5.4 ± 1.2 days and posttransplant hospital stay was 12.1 ± 5.5 days.
Graph 3.12: The rate of early postoperative complication was 4.9%: bleeding in 2 cases (2.0%), perigraft fluid collection in 2 cases (2.0%), wound infection in 1 case (1,0%); 1 graftin doubt of arterial stenosis but the graft’s function improved postoperatively, and no stenosion Doppler ultrasoud at discharge. 3.4.3. Longterm results
Table 3.40: ureter stricture developed in 1 case after JJstent removed (1%), there was no difference in ureter stricture between inverted and noninverted kidney transplant group (p > 0.05).
Graph 3.14 to graph 3.20 and table 3.42: there was no difference in ure and creatinine concentration between inverted and non inverted kidney transplant group in longterm followup.
Graph KaplanMeier 3.21 showed the rate of good graft function by the time: 91% of grafts survived 5 years after transplantation, and the rate of good function grafts was over 80% 8 years after surgery.
CHAPTER4
18
DISCUSSION
4.1. Recipients’ charateristics
Mean age was 36.9 ±11 years old, male/female ratio was 2/1, there was no difference between inverted and noninverted kidney transplant group. Researches of J.M. Gloor et al, of Bayat and et al showed that the average recipient’s age was higher than our study. The incidence of kidney disease leading to chronic renal failure is 36.6%. This result was lower than that of some authors such as Robert P. Pauly (2009) and Haririan (2009).
Patients with hemodialysis less than 2 years accounted for 61.4%, only 2.0% had not been treated by hemodialysis. Robert P. Paly et al (2009) showed that the rate of patients without dialysis was 14.1%, and dialysis less than 2 years accounted for 48%.
Patients with the same blood group accounted for 96.0%, unrelated donors accounted for 20.8% and there was no difference between the two groups of inverted and noninverted kidney transplant. Study of John R.Montgomery et al (2012) showed that there was 40% of unrelated donors. There was a similarity between our study and other studies on blood groups.
Our research showed that the 1st class HLA compatibility accounted for 75.2%, the 2nd class compatibility accounted for 55.4%, and the compatibility of both classes accounted for 49.5%.
In our study, the majority of recipients had normal BMI (68.3%). Recipients with BMI <18.5 accounted for 26.7%, BMI> 25 accounted for a very low rate of 5.0%. Meanwhile, the results in the world showed that the proportion of patients with BMI over 25 is much higher than the results in our study.
4.2. Evaluate the technique of living donor kidney transplant
19
4.2.1. Choose the side of kidney nephrectomy from the donor and side
of iliac fossa to transplant. 4.2.1.1. Choose the side of kidney nephrectomy
In the study, we chose to take a less functional kidney. The rate
of right kidney was higher than left kidney, 56.4% and 43.6%,
respectively. This rate is different from previous reports with a very
high rate of left kidney nephrectomy to transplant: Tran Ngoc Sinh et
al (2012) 74.26% left kidney, Du Thi Ngoc Thu 75.12% left kidney
and Nguyen Truong Giang et al (2012) 100% taking left kidney.
4.2.1.2. Choose the pelvis to transplant the graft
Nguyen Thi Anh Huong (2008) summarized and made the
judgment: there are three position options for conducting kidney
transplant surgery related to the kidneys.
Taking kidneys on any side, then transplant into the same side
iliac fossa.
Taking kidneys on any side, but always choose to transplant into
the right iliac fossa.
Taking kidneys on any side, then grafting into the opposite iliac
fossa (taking the right kidney to transplant into the left iliac
fossa and vice versa).
However, authors like to take the left kidney and graft into the
right iliac fossa by many favorable factors.
Kidney transplantation in the right iliac fossa have outstanding
advantages compared to the left:
+ The technique of transplantation is more advantageous because the right iliac vein is more shallow and horizontal than the left, so the exposure will be easier and faster than the left.
20
+ More advantageous for vascular disposition technique because
the vein tends to be right deviation.
+ More advantageous for graft examination or graft biopsy. Therefore, authors often tend to transplant grafts into the right iliac fossa. My research also followed this trend so 100% of our patients received kidney transplants into the right iliac fossa. 4.2.2.Evaluation of the graft, vascular plasty and ureter. 4.2.2.1. Evaluation of the graft
There was no difference in graft size between inverted and non
inverted kidney transplant group. 4.2.2.2. Evaluation of the ureter
In kidney transplant surgery, only renal artery is the main source of blood supply for ureter. Research of Liselottes et al (2015) has shown that there was no relationship between length of ureter and complications after kidney transplant surgery.
According to Cranston et al. (2001), when a kidney transplant suregery is performed, the ‘golden triangle’ (between the vena cava and the renal vein, the renal sinuses and the lower pole) must be respected. In this study, we always paid attention to respect this "golden triangle". Dissection of ureter and pelvis follows the lower of the kidney pole to the hilum in case of reversing the urinary tract envisioned as dissection according to the edge of the "golden triangle" that the authors mentioned should be respected. This movement will not damage the blood vessels that keep the ureters separated from the renal artery, which will only work to move the triangle so that the urinary excretion line is not kinked when the kidney is inverted.
Our ureter size was similar to other studies. Of course, the length of the graft's ureter is shorter than the length of the normal ureter due to the need to reveal and take the ureter to theposition of crossing anteriorly pelvic arteries.
21
4.2.3. Inverted kidney transplant technique
In placing the grafts into the iliac fossa, we always prioritized the implementation of vascular anastomoses. If the left kidney transplant into the right iliac fossa, just flip the kidneys, if the right kidney transplant into the right iliac fossa, in addition to the flip the need to reverse the pole (inverted kidney transplant technique), the graft can be compatible with blood vessels in coronal plane.
However, in case of inverted kidney transplant, the pathway of the ureteropelvic junction and ureter are upwards. Allen (2014) mentions this problem after performing arterial and venous anasomoses. At that time, it is possible to retake out the graft, irrigate and re transplant that the ureter is downward. But many authors consent that: release the renal pelvis and the renal ureter down to the bladder.
Because of all the outstanding advantages of the inverted kidney transplants described above, we have applied this technique in most right kidney (98.2%) transplant into the right iliac fossa.
The inverted kidney transplant had very good results: there is no vascular complication and we completely managed the reverse ureter which is considered the only disadvantage of the technique. In no case, the upper third ureteral stenosis was folded or kinked due to ureteropelvic reversal, no cases of ureteral necrosis due to injury of ureteral vessels separated from the renal artery. Only 1 case had a stricture of neo ureteral orifice after JJstent removed 1 month (1%). Thus, we did not found any difference in urinary complications in inverted and noninverted kidney transplant groups.
In 2016, Simforooth summed up 79 cases of right kidney transplants and identified the inverted kidney transplant as an easy, safe method and reduced the need for prolonged graft’s vein. Ramesh S. et al (2019) performed the inverted technique in 6/50 (12%) kidney transplants in children from braindead donor and also found no
22
difference in the rate of complications after surgery between inverted and noninverted groups. The author also identified the inverted kidney transplant as a feasible surgical technique to compensate for graft’s anatomical variants or short veins. 4.2.4. Vascular plasty techniques 4.2.4.1. Graft’s arterial plasty technique
In this study, there were 18 cases of grafts with 2 arteries (17.82%), 13 cases without plasty accounted for 72.2%; 27.8% were reformed into 1 artery (2 cases of ‘pantalon’ shape, 3 cases of side connected small artery with main trunk). Antonopoulos (2014) sutured 2 arteries into 1 artery in 77/98 cases of grafts with many arteries, accounted for 78.57%. This rate is higher than our research. According to Allen (2014), although making 2 separated anastomoses takes longer time, he does not like to connect the renal arteries before transplanting to avoid the risk of arterial thrombosis. 4.2.4.2. Graft’s venous plasty technique
The management of graft’s multiple veinsis similar to of multiple arteries. In this study, there were 4 grafts with 2 veins of the same size, so they did not reshaped and kept 2 anastomoses.
Evaluating kidneys in preparation for grafting according to the criteria, good kidney accounted for 96.0%. In case the graftwas taken from the right, due to inverted technique when transplanting, we released the renal pelvis and ureter to avoid kinking urinary tract. The maximum conservation tissues around the ureter and renal pelvis is important to avoid urologic complications after transplantation. 4.2.4.3. Vascular disposition technique
Level 1: lengthenvein by dissection renal hilum. Level 2: assessment of arteries, veins with interdependent compression, so the vessels must be displaced. Level 3: cut the recipient’s internal iliac vein to mobile the external iliac vein, and then make the vein
23
disposition to the right outside of common and external iliac arteries. Christopher J.E. Watson and Peter J. Friend (2014), and Barry (2000) also mentioned the technique of ligating internal iliac vein in order to mobile the external vein in kidney transplantation.
Unlike the study by Du Thi Ngoc Thu, we only performed vascular disposition at level 3 when applying the inverted technique but the graft’s veins were still not long enough. The inverted technique maked the coronal plane of graft’s arteries and veins closer to the recipient’iliac vessels, so there was no need of level 1 and 2 vascular disposition.
There were 91.1% of cases not need vascular disposition, 9/101 cases (8.9%) of level 3 disposition and all of these were inverted kidney transplantbut the graft’s veins still stretch when anastomosed. The rate of vascular disposition in our study was many times lower than that of Du Thi Ngoc Thu's study, maybe part of the reason was that the number of patients in this study was less and we carried out open livingdonor nephrectomy. In order to have confirmation, more research is needed with larger samples. 4.3. Evaluation of living donor kidney transplantation 4.3.1. Intraoperative and postoperative assessement 4.3.1.1. Graft evaluation after revascularization
After revascularization, 98.0% of grafts achieved good results. The study of Tran Ngoc Sinh et al (2012) performed 202 cases of kidney transplantation from live donors at Cho Ray hospital from 1992 to 2010 for 99.5% success rate (201/202 cases). 4.3.1.2. Graft’s warm ischemia
The average warm ischemia time for the 2 groups inverted and noninverted kidney were 35.1 ± 9.5 minutes and 33.5 ± 8.8 minutes, respectively. However, this difference is not statistically significant with p = 0.379> 0.05. Thus, the time for vessels anastomoses in inverted and noninverted groups were the same in our study.
24
4.3.1.3. Time of operation
The duration of surgery was 148.0 ± 30 minutes. There was a statistically significant difference between mean time in the grafts with 2 arteries and the grafts with 1 artery with p = 0.0085, because the 2artery grafts with 13/18 cases (72.2%) performed 2 separate anastomoses with iliac arteries so the time was longer. Comparing the average time between inverted and noninverted group, there was no significant difference with p> 0.05. 4.3.1.4. Intraoperative complications
Intraoperative complications occurred in 3 cases (3.0%): 1 graft with folded long artery, 1 graft with kinked vein, 1 case of bleeding from skin incision of drainage which resutured. In the study of Le Nguyen Vu (2014) on kidney transplantation from braindead donors, there was intraoperative bleeding in 2/38 cases (5.16%). 4.3.2. Evaluation of kidney transplantation in early stage 4.3.2.1. Excretion of urine for days just after surgery
The volume of first 24hour urine was 14.1 ± 4.2 liters. The 24 hour urine volume tended to decrease gradually to the day of discharge in both inverted and noninverted group. At time of discharge, urine volume was 3.2 ± 0.8 liters. This result was similar to that of Le Nguyen Vu’s study (2014) in 38 patients who received kidney transplantation from 20 braindeath donors. 4.3.2.3. Posttransplant hospital stay
The period of postoperative hospital stay in our study was 12.1 ± 5.5 days, longer than that of Hoang Khac Chuan (2016) was 10 days, or Karim Marzouk's research ( 2013) was 9 days. 4.3.2.4. Postoperative complications
Early postoperative complications were in 6/101 cases (4.9%)lower than in the study of F. ReynaSepulveda (2017) 12.7%.
25
Besides, there was bleeding in 2 cases (2.0%), perigraft fluid collection in 2 cases (2.0%).
In our study, wound infection was in 1 case (1%); 1 graft in doubt of arterial stenosis but the graft’s function improved post operatively, and no stenosis on Doppler ultrasoud at discharge; 1 graft loss due to rejection. 4.3.3. Longterm posttransplant evaluation
Only 1 case had a stricture of neo ureteral orifice after JJstent removed 1 month (1%), but we found it not related to the inverted technique.Thus, inverted kidney transplant technique does not increase urologic complications after transplantation as identified by some authors in the world.
Until now, the recipients continue to be followup at Viet Duc hospital. By the end of 2018, 91% of grafts survived 5 years after transplantation, and the rate of good function grafts was over 80% at 8 years after surgery.
The research results showed that living donor kidney transplant is a good treatment option for patients with chronic renal failure. Performing endtoside anastomosis between kidney artery and iliac artery, and applying inverted kidney transplant technique in case of right kidney into right iliac fossa created many advatages in kidney transplantation without increasing posttransplant complications as well as not affecting long graft function.
CONCLUSION
1. Technical characteristics of living donor kidney transplant at VietDuc University Hospital
100% the kidney were transplanted in right iliac fossa. There were 57/101 cases (56.4%) inverted kidney transplant; 98.2% inverted kidney transplat was the right kidney.
26
The endtoside anastomoses were made between renal arteries and external iliac artery in 96.4% grafts with 1 artery, and in all the kidney with 2 arteries.
The rate of applying vascular disposition technique was low
(8.9%). There was no case with renal vein lengthenned.
We use modified LichGregoir extravesical procedure with JJ
stent in all cases.
After revascularization, there were 99% of renal veins and 99%
renal arteries in good condition.
100% posttransplant ureter had good condition. The ureters were pink, good blood supportto the distal portion, good peristalsis and the kidney excreted urine intraoperatively.
The average time for transplant surgery was 148.0 ± 30 minutes.
Results of living donor kidney transplant at VietDuc
2. University Hospital”
Low intraoperative complication, accounted for 3.0%. Early results: 98% of kidney achieved good results, there was no difference in surgical results between the inverted and noninverted kidney transplant groups.
Some characteristics were noted in the postoperative period: + 24hour urine output tended to decrease. + Serumurea and creatinine concentration gradually decreased. + Graft function was assessed normally when the creatinine was in normal range and not reached when the concentration was above 130 µmol/l.
Doppler ultrasound revealed the normal vascular circulationin all grafts (100%); RI of graft’s parenchymal was in normal range (RI ≤ 0.7) in 94,1%. The inverted technique did not affect the graft vascularization.
27
Posttransplant ureteralstricture accounted for 1.0% (at the neo orifice). There was no urologic complications due to the inverted kidney transplant technique.
Results of assessing renal function through creatinine index at monitoring points were stable after 2 years and no different between the inverted and noninverted group.
The grafts were in good condition after 5 years of 91%, after 8
years of more than 80%.
RECOMMENDATIONS
From the research results, we make some recommendations: Anatomosis renal artery end to side with external iliac artery is
the first priority choice in kidney transplant surgery.
It is possible to apply “inverted kidney transplant” when right kidney transplant in the right iliac fossa or left kidney transplant in the left iliac fossa.
