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American Journal of  Medical 
Science and Innovation (AJMSI) 

Recurrent Symptomatic Renal Stones Managed by Repeat Open Nephrolithotomy in a 
Rural Kenyan Hospital

Vonwicks C. Onyango1*, Winston O. Makanga2, Ali J. Kariuki2,  Boniface M. Kioko3, Mumina D. Dido3, Thomas M. Kamau4

William C. Fryda.1

Volume 3 Issue 2, Year 2024
ISSN: 2836-8509 (Online)

DOI: https://doi.org/10.54536/ajmsi.v3i2.2896
https://journals.e-palli.com/home/index.php/ajmsi

Article Information ABSTRACT

Received: May 24, 2024
Accepted: June 27, 2024
Published: July 03, 2024

Kidney stone disease (nephrolithiasis, urolithiasis, and renal calculi) is characterized by 
the formation of  both symptomatic and asymptomatic obstructive and non-obstructive 
calculi in the urinary tract. Calcium oxalate stones are the most common type, related to 
the consumption of  large amounts of  oxalate-rich foods. Other stones are made of  calcium 
phosphate, hydroxyapatite, uric acid, cystine, and struvite. Urolithiasis is increasingly being 
reported in both urban and rural Kenya. Minimally invasive surgical treatment of  symptomatic 
stones is the current standard of  care, but open nephrolithotomy remains a viable option in 
selected patients. Nonetheless, the rates of  stone recurrence remain high, increasing from 
15% at 1 year to 50% at 10 years due to multifactorial risk factors. In this study, we report the 
case of  a rural Kenyan patient who underwent the third open nephrolithotomy in 10 years 
for recurrent symptomatic stones and whose biochemical analysis has guided subsequent 
preventative dietary efforts against stone recurrence.

Keywords
Kidney Stone Disease, 
Nephrolithiasis, Urolithiasis, 
Renal Calculi, Calcium Oxalate 
Stones, Recurrent Kidney Stones, 
Nephrolithotomy, Kenya

1 Department of  Medicine, St. Joseph RV Hospital, Gilgil, Nakuru, County, Kenya
2 Department of  Surgery, St. Joseph Rift Valley Hospital, Gilgil, Nakuru County, Kenya
3 Department of  Anesthesia, St. Joseph Rift Valley Hospital, Gilgil, Nakuru County, Kenya
4 Department of  Radiography, St. Joseph Rift Valley Hospital, Gilgil, Nakuru County, Kenya
* Corresponding author’s e-mail: drvonczelo@gmail.com

INTRODUCTION
Kidney stone disease (nephrolithiasis, urolithiasis, renal 
calculi) is characterized by the occurrence or formation 
of  calculi in the urinary tract. It is encountered in primary 
health care settings, with a prevalence of  up to 8.8% 
in a US survey (10.6% among men vs. 7.1% among 
women) (Scales et al., 2012). Though initially thought to 
be rare in indigenous African populations, there have 
been increasing cases of  urolithiasis reported in Kenya 
over the last four decades (Musau, 2010; Ngugi et al., 
2010). The risk of  urolithiasis increases with age, from 
5.1% in males and 5.8% in females aged 20-39 years 
to 19.7% in males and 10.6% in females aged 80 years 
and above (Chewcharat & Curhan, 2021). Symptomatic 
patients present with renal colic, hematuria, frequency, 
irritability, dysuria, nausea and vomiting, and features of  
renal failure in some cases (Khan et al., 2016). 70-80% of  
all renal stones are composed of  calcium oxalate. Other 
components include calcium phosphate, hydroxyapatite, 
uric acid, cystine, and struvite (Lieske et al., 2014). Risk 
factors for urolithiasis include urinary factors such as 
hypercalciuria (Coe et al., 2016), hyperoxaluria (Owino et 
al., 2023), hyperuricosuria, hypocitraturia, oliguria, and 
the urine pH (Ferraro et al., 2024). Dietary factors include 
a lower fluid intake (Gamage et al., 2020), consuming 
higher-than-recommended levels of  dietary calcium, 
including supplements (Sorensen, 2014), and taking high 
levels of  oxalate-containing foods, e.g., sweet potatoes, 
spinach, cabbages, ground nuts, green beans, etc. 
(Mitchell et al., 2019). Medicinal drugs, e.g., furosemide, 

acetazolamide, topiramate, laxatives, and long-term 
steroids, may also promote stone formation (Daudon 
et al., 2018). Other risk factors include family history, 
genetic factors, and medical illnesses like hypertension, 
chronic kidney disease, hyperparathyroidism, diabetes, 
gout, and obesity (Alelign & Petros, 2018). The American 
Urological Association and the European Association 
of  Urology have issued guidelines for the diagnosis and 
management of  renal stones (Pearle et al., 2014; Türk et 
al., 2016). In summary, the diagnostic modalities include 
a urinalysis (for hematuria and to rule out infections), 
a non-contrast CT scan of  the abdomen and pelvis 
(the imaging modality of  choice), and a kidney-bladder 
ultrasound (especially in pregnant women). A plain 
abdominal x-ray may show radio-opaque stones but does 
not detect hydronephrosis, among other limitations. The 
management of  urolithiasis includes pain control and 
supportive care, conservative medical expulsive therapy, 
surgical therapy (i.e., minimally invasive procedures like 
extracorporeal shock wave lithotripsy, ureteroscopy, and 
percutaneous nephrolithotomy) (Rodríguez & Sacco, 
2015), or open stone removal (Çakici Ö et al., 2017). 
The current status of  practice prefers minimally invasive 
procedures, but open surgery remains an option (in large, 
complex stones, among other indications) as per the 
guidelines. Renal stones have a high rate of  recurrence 
that increases from 15 percent at 1 year, 35 to 40 percent 
at 5 years, and 50 percent at 10 years (Ferraro et al., 2017). 
The risk factors for recurrence include a younger age 
of  onset, male sex, pregnancy, dietary factors, obesity, 



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diabetes, recurrent urinary tract infections, a high number 
and size of  previous stones, etc. (Vaughan et al., 2019)

Case Summary
A 76-year-old man, a married father of  five and a 
retired head teacher from Nyakach-Koguta, Kisumu 
County, Kenya, presented to us with a third episode of  
severe renal colic and recurrent gross hematuria due to 
symptomatic bilateral renal stones, which were worse on 
the left side. He had previously undergone two episodes 
of  open nephrolithotomy elsewhere, i.e., in 2014, where 
he had a bilateral nephrolithotomy, and in 2020, where he 
had a left nephrolithotomy. In both cases, multiple stones 
of  various sizes were reportedly extracted. Unfortunately, 
no biochemical analysis of  the stones was done then. He 
had well-controlled hypertension on nifedipine, losartan, 
and atenolol. Prior to the first episode of  kidney stones, 
he had been on hydrochlorothiazide and nifedipine. He 
had been regularly using paracetamol and tramadol for 
pain control. He had no other cardiovascular risk factors 

and did not smoke or take ethanol. He had no history 
of  recurrent urinary tract infections. He intermittently 
took tamsulosin-dutasteride tablets for a benign prostate 
hyperplasia diagnosed two years prior. His vital signs 
were normal. On physical examination, he was in obvious 
pain distress, with an abdominal exam showing bilateral 
posterolateral lumbar scars with marked tenderness 
over the left lumbar region but no peritonism. A rectal 
exam showed an enlarged, soft prostate. A urine dipstick 
showed 3+ blood, and a urinalysis showed no urinary 
tract infection.
He had a normal creatinine of  0.9 mg/dL, normal 
random glucose and a complete blood count, and a 
normal prostate-specific antigen test of  2.4 ng/mL. 
A prior erect abdominal x-ray showed left-sided radio-
opaque renal stones. See figure 1. A plain CT scan of  
the kidney-ureter-bladder (KUB) showed multiple stones 
in the left kidney (both obstructive and non-obstructive) 
and a non-obstructive stone in the right kidney. See figure 
2 and the attached CT scan report in figure 3. 

Figure 1: A plain, erect abdominal x-ray showing radio-opaque stones in the left kidney (appearing as white crystals, 
marked with letter L)

Figure 2: A plain CT scan kidney-ureter-bladder showing multiple radio-opaque stones appearing white, predominantly 
in the left kidney (marked with red arrows)



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He had an uneventful postoperative recovery and was 
discharged six days later. He has remained stable and 
pain-free four months later. A biochemical analysis 
of  the extracted stones by Fourier-transform infrared 
spectrometry showed they comprised 80% calcium 
oxalate, 10% uric acid, and 10% carbonate apatite. See 
table 1. A detailed dietary history revealed that he is a 
subsistence farmer who grows and routinely consumes 
ground nuts, sweet potatoes, spinach, cabbages, and red 
and green beans. He also routinely takes beef  and has 
variously used over-the-counter calcium supplements. 
These foods are rich in oxalate and were deemed to be 

Figure 3: A report of  the CT scan of  the kidney-ureter-bladder

Figure 4: Two large renal stones extracted from the left 
kidney during open nephrolithotomy. Left: the stones 
covered by fibrous tissue. The largest stone measured 
about 2.8cm by 1.6cm; Right: the smaller stone measured 
about 1cm by 0.8cm.

Table 1: Biochemical Analysis of  the Renal Stones by 
Fourier-Transform Infrared Spectrometry
Test Results Units
Calculi Analysis
Number of  stones 1
Type Kidney stone
Size 2.8 cm
Color Brown 
Calcium oxalate monohydrate 80.0 %
Calcium oxalate dihydrate 0.0 %
Calcium phosphate 0.0 %
Uric acid dihydrate 10.0 %
Uric acid anhydrous 0.0 %
Sodium urate 0.0 %
Magnesium ammonium 
phosphate

0.0 %

Amorphous carbonated 
calcium phosphate

0.0 %

Ammonium urate 0.0 %
Carbonate apatite 10.0 %
Method of  analysis Fourier-transform 

infrared spectrometry

most likely responsible for the recurrent nature of  the 
stones. Besides, he had been taking just about 200-600ml 
of  drinking water on a daily basis. He was advised to 
avoid oxalate-rich foods, take 2 to 3 liters of  drinking 
water daily, and received a comprehensive nutritional 
advice to forestall the recurrence of  the stones.

Due to personal preference, he underwent a repeat 
open left nephrolithotomy with the extraction of  hard, 
brownish renal stones, as shown in figure 4.



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DISCUSSION
Calcium oxalate stones are the most common renal 
stones in practice. Common foods in rural Kenya that 
are rich in oxalate include spinach, cabbages, ground nuts, 
sweet potatoes, bananas, kales (commonly called sukuma 
wiki in Kenya), green beans, tomatoes, etc. Our patient 
cultivated and consumed these foodstuffs for all his life. 
Oxalate released from these foods forms compounds 
with calcium (calcium oxalate), which leads to increased 
urinary supersaturation, crystal formation, crystal-cell 
interaction causing tubular epithelial injury, and further 
crystal nucleation, aggregation, and stone formation 
(Tsujihata, 2008). This process is compounded by adverse 
dietary practices, including low fluid intake with resulting 
low urine volume and thus supersaturation of  urine with 
lithogenic factors, a high animal protein diet causing 
high levels of  calcium and urate to be excreted, a high 
salt diet that increases urinary calcium excretion, and 
excessive calcium supplementation (usually by over-the-
counter tablets for osteoarthritis), which further increases 
urinary calcium. Our patient admitted to taking no more 
than one liter of  fluids daily (including 200-600mls of  
drinking water), regularly taking beef, and using calcium-
vitamin D supplements for his osteoarthritis. The patient 
was given practical dietary advice that included restricting 
consumption of  oxalate-containing foods, increasing the 
amount of  oral fluids to 2-3 liters daily, reducing dietary 
salt, and consuming a diet rich in calcium (without calcium 
supplementation) in order to maintain his skeletal health 
(Prezioso et al., 2015). The risk of  recurrences of  renal 
stones increases with age, two or more previous histories 
of  stones, male sex, family history, diabetes, obesity, a 
stone-forming diet, chronic kidney disease, etc. (Vaughan 
et al., 2019). For decades, hydrochlorothiazide has been 
used to prevent the recurrence of  renal stones. However, 
the recent NOSTONE trial did not show any benefit 
of  hydrochlorothiazide use compared to placebo in 
preventing the recurrence of  stones (Dhayat et al., 2023). 
Our patient was previously on hydrochlorothiazide, which 
was stopped due to a prior episode of  hyperuricemia. 
He was not put on preventative hydrochlorothiazide 
thereafter. Minimally invasive therapy is currently 
preferred for surgically managing symptomatic renal 
stones. However, in a rural Kenyan setting, patients must 
be referred to centers (usually in faraway towns) where 
such services may be available. The services are costly and 
not readily affordable. This is why our patient (and his 
family) chose the cheaper, open stone removal approach 
this time and previously. Besides, he was deemed to 
have a complex stone burden and thus unlikely to fully 
benefit from less-invasive approaches (El-Husseiny & 
Buchholz, 2012). The biochemical analysis of  renal 
stones is only possible in advanced laboratories located 
in large diagnostic centers and is costly. This is why it 
had not been done previously for our patient. Obviously, 
knowledge of  the composition of  the stones helps guide 
long-term preventative efforts (Dawson & Tomson, 
2012). 

CONCLUSION
Renal stones are increasingly being reported in both urban 
and rural Kenya. Foods that are rich in oxalate, calcium, 
and urate content; as well as concurrent medical illnesses 
(among other risk factors), may explain the occurrence 
and recurrence of  renal stones in these populations. 
Although a minimally invasive surgical approach is 
preferable for symptomatic stones, open surgery is 
indicated in selected patients. A biochemical analysis of  
the stones to determine their exact composition helps 
guide preventative efforts against stone recurrence.

Acknowledgement
The authors acknowledge the following staff  of  St. Joseph 
RV Hospital, Gilgil, for their assistance with managing 
this patient: Fred Aruwa, John Kiprono, Priscah Kamau, 
and Sonia Nginyo from theater; Francis Wambugu, 
Steve Kiarie, and Mary-Hellen Akinyi from the men’s 
ward; Thomas Kamau, Silas Odhiambo, Rose Makanga, 
Joseph Nginyo, and Pauline Nyagah from the outpatient 
department; and Seth Manera and Steve Nyagah from the 
hospital administration.

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