orthoropic ileal neobladder has been employed in the
treatment of patients with end-stage urinary bladder cancers and other diseases
requiring cystectomy in humans. Intramural tunnel techniques such as the
W-urinary reservoir with serous-lined extramural tunnel (WUR) have been reported
to be complicated, often resulting in vesicoureteral reflux. This research was therefore designed to
replicate the WUR technique in pigs, to modify it to a hanging ureterovesical
anastomosis (HUVA), and to compare surgical outcomes of the two techniques.
Twenty healthy Large White gilts, 6 - 7 months of age, and weighing 34.5 ± 2.04
kg were used for the research. They were
assigned to four groups (n =5), CTR, OIN, HUVA and IRA. The CTR was the
negative control group. No surgery was
carried out in animals in this group. In
the OIN and HUVA groups, the urinary bladder was excised and replaced with 40 -
45 cm of detubularized ileal segment using the WUR technique. In the OIN, the ureters were tapered in the
neobladder mucosa, while in the HUVA, 1 cm of the ureter was allowed to hang in
the neobladder lumen. The IRA was the positive control group and animals in
this group underwent only ileal resection and anastomosis. Ureteral stent was implanted for the
collection of urine samples and replaced with urinary catheter after the 10th
postoperative day, while blood samples were collected by venipuncture of the
external jugular vein. Blood and urine samples were taken pre-operatively and
on postoperative days 1, 2, 3, 7, 14, 28, 56, 84 and 112. The duration of
surgery was significantly higher in the OIN and HUVA groups than in other
groups. The histology of the kidneys
did not show any pathologies up to the 112th day post-surgery, while
the neobladder retained the histology of the traditional ileum up to the 112th
postoperative day. Postoperatively, mean urine pH, chloride, potassium,
creatinine and blood urea nitrogen were significantly higher (P ≤ 0.05) in the
OIN and HUVA groups than in the CTR and IRA groups, while serum bicarbonate and
sodium concentrations were significantly lower (P ≤ 0.05) in the OIN and HUVA
groups. Urine samples from animals in
all the groups tested negative for ketones, nitrites, glucose, ascorbic acid,
blood, urobilinogen, leucocytes, and proteins. The frequency of complications
such as diarrhoea, mucoid urine, anorexia, weakness, ureteral sternosis,
metabolic acidosis, urinary tract infection, and death were higher in the OIN
and HUVA groups than in the CTR and IRA groups.
It was therefore concluded that urinary bladder replacement is possible
in the pigs, and that the HUVA technique is as efficient as the conventional
WUR as a method for urinary bladder replacement. Use of pigs as a model for
transitional research therefore has great potentials.
TABLE OF CONTENTS
Title
page i
Declaration ii
Certification iii
Dedication iv
Acknowledgement v
Table
of Contents vii
List
of Tables xi
List
of Figures xii
List
of Plates xiii
Abstract
xiv
CHAPTER 1 INTRODUCTION 1
1.1 Background of the
study 1
1.2 Statement of
problems 9
1.3 Objectives of the
study 11
1.4 Justification 12
CHAPTER 2 LITERATURE REVIEW 14
2.1 Pigs in research 14
2.2 Similarities
between pigs and humans 14
2.2.1 The heart 14
2.2.2 The urinary system 15
2.3 Anatomy of the
urinary system 17
2.3.1 The kidneys 17
2.3.2 The ureter 21
2.3.3 The urinary bladder 22
2.3.4 The urethra 23
2.4 Catheterization
of the porcine urinary bladder 25
2.5 Physiology of
micturition 27
2.6 Micturition in
neobladder patients 30
2.7 Surgeries of the
urinary system 31
2.7.1 Renal surgeries 31
2.7.2 Surgeries of the
ureters 35
2.7.3 Urinary bladder
surgeries 37
2.8 Urinary bladder
reconstruction 42
2.8.1 Ureterosigmoidostomy 45
2.8.2 The
sigma rectum, or Mainz II pouch 46
2.8.3 The
Studer neobladder 46
2.8.4 The
orthotopic Kock ileal reservoir 47
2.8.5 The
T-pouch ileal neobladder 47
2.8.6 The
Padua ileal neobladder (‘‘vesica ileale Padovana’’) 48
2.8.7 Conjoined subserosal
ureteral implantation in a cross-
folded
ileal reservoir (‘‘I-pouch’’). 49
2.8.8
Hautmann ileal neobladder 49
2.8.9
W-reservoir with serous-lined extramural
tunnel 50
2.9 Antireflux
mechanism 51
2.10 Complications
of gastrointestinal resection 54
2.10.1 Resection
of the stomach 55
2.10.2 Resection of the
jejunum 55
2.10.3 Resection of the ileum 56
2.10.4 Terminal ileal
resection 57
2.10.5 Ileocaecal valve 58
2.10.6 Caecum 58
2.10.7 Colon 59
2.11 Metabolic
disturbances associated with continent
reservoirs
of digestive tract origin 59
2.12 Complications
of ileal neobladder 63
2.12.1 Wound
infection and dehiscence: 63
2.12.2 Anastomotic
leaks: 64
2.12.3 Bladder stones 64
2.12.4 Ureteroileal
strictures 65
2.12.5 Spontaneous
neobladder rupture 66
2.12.6 Incisional
hernia 67
2.12.7 Fistula
formation 67
2.12.8 Paralytic
ileus 67
2.12.8 Urinary
retention 68
2.12.10 Urinary
incontinence 68
2.13 Preparation
of the ileal neobladder 69
2.14 Absorptive
functions of the intestines 72
CHAPTER 3 MATERIALS AND METHODS 74
3.1 Materials 74
3.2 Methods 75
3.2.1
Ethical approval 75
3.2.2 Experimental animals 75
3.2.3
Experimental
design 76
3.2.4
Pre-surgical
evaluation 76
3.2.5
Pre-surgical preparation 79
3.2.6
Anaesthetic
protocol 79
3.2.7
Surgical technique 79
3.2.8
Postoperative
care and evaluation 95
3.2.9
Data analysis 95
CHAPTER 4 RESULTS AND DISCUSSION 96
4.1
RESULTS 96
4.1.1 Gross evaluation of the neobladder 96
4.1.2 Histologic evaluation of the kidneys 98
4.1.3 Histology of the
neobladder 100
4.1.4
Duration of the surgery 102
4.1.5 Mean
urine pH 103
4.1.6 Urine
specific gravity 104
4.1.7
Mean serum chloride concentration 105
4.1.8
Mean serum bicarbonate concentration 106
4.1.9 Serum potassium concentration 107
4.1.10
Mean serum sodium concentration 108
4.1.11 Mean
serum creatinine concentration 109
4.1.12 Mean
blood urea nitrogen concentration 110
4.1.13 Frequency
of postoperative complications 111
4.1.14 Urinalysis 113
4.2 Discussion 116
CHAPTER 5 CONCLUSION AND RECOMMENDATIONS 126
5.1 CONCLUSION 126
5.2 RECOMMENDATIONS 127
REFERENCES 129
LIST
OF TABLES
Table
4.1: Major complications observed
in the respective groups
and
their frequencies of occurrence in the various groups 112
Table
4.2 Urinalysis of pigs in the
CTRO, OIN, HUVA and IRA groups 114
LIST
OF FIGURES
Fig
4.1: Duration of surgery (minutes) in the CTRO, OIN, HUVA and
IRA
groups 102
Fig
4.2 Mean urine pH in the CTRO, OIN, HUVA
and IRA groups 103
Fig
4.3 Urine specific gravity in the CTRO,
OIN, HUVA and IRA groups 104
Fig
4.4 Mean serum chloride concentration in
the CTRO, OIN, HUVA and
IRA groups 105
Fig 4.5 Mean
serum bicarbonate concentration in the CTRO, OIN,
HUVA and IRA groups 106
Fig 4.6 Mean
serum potassium concentration in the CTRO, OIN,
HUVA and IRA groups 107
Fig
4.7 Mean serum sodium concentration in
the CTRO, OIN, HUVA
and IRA groups 108
Fig
4.8 Mean blood creatinine concentration
in the CTRO, OIN,
HUVA and IRA groups 109
Fig
4.9 Mean blood urea nitrogen
concentration in the CTRO, OIN,
HUVA and IRA groups
110
LIST OF PLATES
Plate
3.1. Urinary catheterization for urine collection from the urinary bladder 78
Plate
3.2. A segment of the distal ileum resected showing intact mesenteric
attachment 82
Plate
3.3. Suturing of the medial arms of the W-shaped ileal segment. 83
Plate
3.4. Uniting of the lateral arms of the “W” to the sutured medial wings 84
Plate
3.5. Detubularized ileal segment showing exposed ileal mucosa 85
Plate
3.6. The distal end of the left ureter 86
Plate
3.7. Arrows show the visceral surface of the extramural tunnel of the
neobladder 88
Plate
3.8. Both ureters were attached such that they did not extend into
the
lumen of the neobladder. 89
Plate
3.9. Arrow shows the ureter within the extramural tunnel, and
extending
intraluminally into the neobladder. 90
Plate
3.10. The neobladder is formed by suturing the free borders together.
Arrow
shows the sutured free borders. 92
Plate
3.11. The urinary bladder (A) is being removed by transecting it
at
its neck, distal to the point of attachment of the ureters. 93
Plate
3.12. Attaching the neobladder to the
urethra 94
Plate
4.1. Organ locations in situ
in the OIN and HUVA groups on day 112 97
Plate
4.2 Histology of the kidney of pig in
the OIN group at day112 98
Plate
4.3 Histology of the kidney of pig in
the HUVA group at day 112 99
Plate
4.4 Histology of the ileal neobladder (x 40) in the OIN group at day 112 100
Plate
4.5 Histology of the ileal neobladder (x
40) in the HUVA group at day 112 101
NJOKU, N (2023). Modification Of The W-Urinary Reservoir With Serous-Lined Extramural Tunnel For Enhancement Of Antireflux Mechanism - A Porcine Model. Mouau.afribary.org: Retrieved Dec 25, 2024, from https://repository.mouau.edu.ng/work/view/modification-of-the-w-urinary-reservoir-with-serous-lined-extramural-tunnel-for-enhancement-of-antireflux-mechanism-a-porcine-model-7-2
NJOKU, NJOKU. "Modification Of The W-Urinary Reservoir With Serous-Lined Extramural Tunnel For Enhancement Of Antireflux Mechanism - A Porcine Model" Mouau.afribary.org. Mouau.afribary.org, 10 Aug. 2023, https://repository.mouau.edu.ng/work/view/modification-of-the-w-urinary-reservoir-with-serous-lined-extramural-tunnel-for-enhancement-of-antireflux-mechanism-a-porcine-model-7-2. Accessed 25 Dec. 2024.
NJOKU, NJOKU. "Modification Of The W-Urinary Reservoir With Serous-Lined Extramural Tunnel For Enhancement Of Antireflux Mechanism - A Porcine Model". Mouau.afribary.org, Mouau.afribary.org, 10 Aug. 2023. Web. 25 Dec. 2024. < https://repository.mouau.edu.ng/work/view/modification-of-the-w-urinary-reservoir-with-serous-lined-extramural-tunnel-for-enhancement-of-antireflux-mechanism-a-porcine-model-7-2 >.
NJOKU, NJOKU. "Modification Of The W-Urinary Reservoir With Serous-Lined Extramural Tunnel For Enhancement Of Antireflux Mechanism - A Porcine Model" Mouau.afribary.org (2023). Accessed 25 Dec. 2024. https://repository.mouau.edu.ng/work/view/modification-of-the-w-urinary-reservoir-with-serous-lined-extramural-tunnel-for-enhancement-of-antireflux-mechanism-a-porcine-model-7-2