https://doi.org/10.53453/ms.2025.5.9
A prospective cohort study: comparative analysis of liver enzyme
and other biochemical blood markers 24 hours after laparoscopic
surgery with and without liver retractor use
Mindaugas Kiudelis
1
, Rūta Maželytė
1
, Gabija Grežeckaitė
2
, Jovita Tamošiūnaitė
2
1
Hospital of Lithuanian University of Health Sciences Kaunas Clinics, Surgery Department, Kaunas, Lithuania
2
Medical Academy of Lithuanian University of Health Sciences, Kaunas, Lithuania
Abstract
Introduction. Laparoscopic gastric surgery offers numerous advantages over open procedures but is associated
with transient liver enzyme elevations (TLEE), particularly in cases involving liver retraction. Nathanson liver
retractor (NLR) is commonly used in gastric surgeries to improve surgical exposure but may contribute to TLEE.
Aim: To evaluate the impact of liver retractor use during laparoscopic gastric surgeries on liver enzyme tests and
other biochemical blood markers and assess its clinical significance.
Methods. A prospective cohort study was conducted including 119 patients undergoing elective laparoscopic
surgeries at the Lithuanian University of Health Sciences Hospital Kaunas Clinics between June and November
2024. Patients were divided into two groups: the retractor group (n=59; fundoplication or gastric resection) and
the control group (n=60; cholecystectomy). Laboratory parameters were assessed preoperatively, immediately
postoperatively, and on the first postoperative day. Statistical analysis included ANCOVA, logistic regression,
and ROC curve analysis.
Results. ALT and AST levels were significantly elevated postoperatively in the retractor group (p<0.001).
Surgery duration >75 min and >95 min were predictive of ALT and AST elevations, respectively. CRP and LDH
levels were significantly higher in the retractor group (p<0.001 and p=0.007), while bilirubin, coagulation and
renal markers showed less pronounced differences. ROC analysis identified surgery duration as a moderate
predictor of AST elevation (AUC=0.683).
Conclusion. Liver retraction during laparoscopic gastric surgery is associated with transient elevations in liver
enzymes and inflammatory markers, particularly in prolonged procedures. These findings emphasize the
importance of perioperative monitoring and highlight the need for further research on long-term hepatic outcomes.
Keywords: laparoscopy, gastric surgery, liver retractor, liver enzymes.
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Medical Sciences 2025 Vol. 13 (3), p. 94-112, https://doi.org/10.53453/ms.2025.5.9
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1. Introduction
One of the first procedures similar to our modern
laparoscopic surgery was performed in 1901 by
Georg Kelling [1]. Nowadays laparoscopic
surgery has largely replaced open surgical
techniques due to its numerous advantages,
including reduced postoperative pain, shorter
recovery time, minimal scarring, lower risk of
infection and decreased hospital stays [2].
However, despite these benefits, laparoscopy
presents certain disadvantages, primarily related
to longer surgery duration and the creation of
pneumoperitoneum. The increased intra-
abdominal pressure resulting from
pneumoperitoneum can cause more surgical
stress, changes in blood circulation and even
reduced pulmonary compliance [3-6]. During
certain laparoscopic procedures, such as gastric
surgeries (e.g, fundoplication, gastric resection)
retraction of the left liver lobe is performed to
enhance exposure of the upper gastrointestinal
tract. Various liver retraction techniques exist,
with the Nathanson liver retractor being one of
the most commonly used [7-9]. However,
prolonged retraction and surgical manipulation
of the liver can cause transient liver damage.
This is often evidenced by postoperative
elevation of liver enzyme levels, primarily
attributed to impaired hepatic blood flow during
retraction [10-13]. In rare cases, excessive
pressure created by the liver retractor has led to
liver parenchymal necrosis [14]. Although
studies identified various factors contributing to
postoperative liver enzyme elevation - such as
pneumoperitoneum, anesthetic agents, ligation
of the aberrant left hepatic artery - there is
limited research specifically evaluating the
clinical impact of liver retractor use,
postoperative liver injury and perioperative
laboratory test result data [10, 11]
The aim of our study is to evaluate the impact of
the liver retractor use during laparoscopic gastric
surgeries on liver function tests and other
biochemical blood markers and assess its clinical
significance.
2. Materials and Methods
This was a prospective cohort study, in which
119 consecutive patients who underwent elective
laparoscopic surgeries were enrolled. Patients
were treated at the Lithuanian University of
Health Sciences Hospital, Kaunas Clinics,
between June 2024 and November 2024. All
patients gave their written informed consent, and
the local ethics committee approved the study
(No. BE-2-75).
Patients were categorized into two groups based
on the type of surgery performed. The study
group included patients diagnosed with hiatal
hernia (n=46) and histologically confirmed
primary gastric adenocarcinoma (n=13). These
patients underwent laparoscopic fundoplication
(LF) or laparoscopic subtotal gastric resection
(LSGR) respectively. The control group
consisted of patients diagnosed with
cholelithiasis (n=60), all of whom underwent
laparoscopic cholecystectomy (LC). Patients
eligible for inclusion were those scheduled for
elective LF, LSGR or LC surgeries. The scheme
of the retrospective study is shown in Figure 1.
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Figure 1. Patients included in study
Exclusion criteria for this study included:
pregnancy, a history of chronic liver disease,
including positive tests for hepatitis B virus or
hepatitis C virus or liver cirrhosis, chronic
alcohol abuse, systemic illnesses such as liver,
kidney, or heart failure, current use of
medications known to adversely impact hepatic
function. Patients undergoing urgent or
emergency surgeries, as well as those whose
procedures were converted from laparoscopy to
laparotomy, were excluded.
Clinical data were obtained from patients’
medical records throughout their hospital stay.
The collected information included patient
demographics (sex, age, body mass index (BMI;
kg/m²), preoperative clinical data (primary
diagnosis, comorbidities and current
medications), laboratory blood test results
(comprehensive blood analyses) and operative
and postoperative outcomes (surgery duration,
type of procedure, length of hospital stay,
operative and postoperative complications).
Additionally, abdominal ultrasonography was
performed for all patients to measure the
dimensions of the liver’s left lobe. The measured
laboratory parameters included hematological
(complete blood count) and electrolyte
(potassium, sodium) markers, renal function
tests (urea, creatinine), liver function tests
(aspartate aminotransferase (AST), alanine
aminotransferase (ALT), total bilirubin,
conjugated bilirubin), C-reactive protein (CRP),
lactate dehydrogenase (LDH), coagulation
profiles (international normalized ratio (INR),
activated partial thromboplastin time (aPTT).
Laboratory parameters were assessed
preoperatively, in the immediate postoperative
period, and on the first postoperative day.
All surgeries were performed by one
experienced surgeon under a standardized
general anesthesia protocol. Patients undergoing
LC, LF, LSGR were positioned in a head-up
position throughout the surgery.
Pneumoperitoneum was created by inserting a
Veress needle above the umbilicus and
insufflating CO₂ into the abdominal cavity.
Subsequently, a 10 mm port was introduced
using Hasson's technique to access the
abdominal cavity and insert the videoscope,
allowing direct visualization of the peritoneal
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cavity during the placement of additional 5 mm
ports. The number and arrangement of ports
were adjusted based on the specific procedure,
with pneumoperitoneum pressure maintained at
12–14 mmHg in all instances.
For LF and LSGR surgeries retraction of the left
liver lobe was performed using a Nathanson liver
retractor (NLR). The NRL was inserted near the
xiphoid process and positioned close to the
hepatic hilus, under the left liver lobe. Liver
retraction was not used for LC surgeries as they
were control group patients.
Statistical analysis
BM SPSS Statistics Version 29.0.0.0 and
Microsoft Excel Version 16.89.1 were used for
statistical analysis. Impact of the liver retractor
use on previously described laboratory blood test
results changes, demographic characteristics,
liver left lobe dimensions and surgery duration,
were analyzed in both intervention and control
groups. To detect significant differences
between the groups and across different time
points, univariate analysis of covariance
(ANCOVA) was applied. Statistically
significant variables were then subjected to
binary logistic regression analysis. Receiver
operating characteristic (ROC) curve analysis
was performed to analyse whether the duration
of surgery and BMI were prognostic markers for
predicting liver enzyme elevation after surgery.
Statistical significance was set at p <0.05.
3. Results
Between June and November 2024, a total of 119
patients were divided into two groups based on
the type of surgery they underwent. The study
group consisted of 59 patients, including those
diagnosed with hiatal hernia who underwent
laparoscopic fundoplication, and those with
histologically confirmed primary gastric
adenocarcinoma who underwent laparoscopic
subtotal gastric resection. The control group
included 60 patients diagnosed with
cholelithiasis, all of whom underwent
laparoscopic cholecystectomy. All patients
included in the study were scheduled for elective
surgery.
Baseline characteristics were compared between
groups (Table 1). Statistically significant
differences were observed in age (p = 0.015) and
surgery duration (p < 0.001), with the study
group comprising older patients who underwent
longer procedures. Other baseline characteristics
showed no statistically significant differences (p
> 0.05).
Table 1. Demographic characteristics, body mass index (BMI), surgery duration, left liver lobe dimensions
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Electrolyte levels were evaluated at three time
points: preoperatively, immediately after
surgery, and on the first postoperative day.
Potassium levels (Figure 2) increased
significantly after surgery and remained elevated
on the first postoperative day (p < 0.001);
however, there was no significant difference
between groups (p = 0.442). Sodium levels
(Figure 3) also varied significantly across all
time points (p < 0.001), with a significant initial
drop followed by a subsequent rise. Notably,
preoperative sodium levels were significantly
lower in the study group compared to the control
group (p = 0.017).
Renal function was assessed by measuring
creatinine and urea levels. Creatinine levels
(Figure 4) remained stable across time points in
both groups (p = 0.115), with no intergroup
difference (p = 0.595). In contrast, urea levels
(Figure 5) significantly increased on the first
postoperative day in both groups (p < 0.001),
though the difference between groups did not
reach statistical significance (p = 0.075).
Inflammatory response was monitored via C-
reactive protein (CRP) levels (Figure 6), which
significantly increased postoperatively in both
groups (p < 0.001). However, the study group
exhibited higher CRP levels immediately after
surgery and overall compared to the control
group (p < 0.001).
Hepatocellular damage was evaluated through
AST and ALT levels. Postoperative ALT levels
(Figure 7) increased immediately after surgery
and were significantly elevated on the first
postoperative day in both groups (p<0.001).
Moreover, ALT levels were significantly higher
in the retractor group compared to the control
group (p<0.001). Liver retraction time may be a
risk factor for postoperative elevation of liver
enzymes. Based on receiver operating
characteristic (ROC) curve analysis the duration
of surgery is not a strong prognostic marker for
predicting ALT elevation (Figure 8) after
surgery (AUC=0.619, p=0.125). The cutoff
point from the ROC curve was taken as 75 min.
Logistic regression analysis was performed to
assess the likelihood of ALT elevation (>100
IU/L) on the first postoperative day in the
retractor group. The odds ratio was 3.47,
indicating that patients undergoing surgery
lasting more than 75 minutes were
approximately 3.5 times more likely to
experience ALT elevation.
Similarly, postoperative AST levels (Figure 9)
were significantly elevated on the first
postoperative day in both groups (p<0.001).
Additionally, AST levels were significantly
higher in the retractor group than in the control
group (p<0.001). The duration of surgery is a
moderate prognostic marker for predicting AST
elevation (Figure 10) after surgery (AUC=0.683,
p=0.015). The cutoff point from the ROC curve
was taken as 95 min. Logistic regression analysis
was performed to assess the likelihood of AST
elevation (>100 IU/L) on the first postoperative
day in the retractor group. The odds ratio was
6.26, indicating that patients undergoing surgery
lasting more than 95 minutes were
approximately 6 times more likely to experience
AST elevation.
Based on receiver operating characteristic
(ROC) curve analysis the predictive power of
BMI (Figure 11) was similar to that of surgery
duration for AST and ALT elevation
(AUC=0.623 and 0.623, respectively), but it did
not reach statistical significance (p=0.101 and
p=0.112, respectively).
In the control group, total bilirubin levels
increased immediately after surgery and on the
first postoperative day compared to the
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preoperative levels, indicating a statistically
significant rise after surgery (p=0.031), as
depicted in Figure 12. However, in the retractor
group, no significant differences were observed
across time periods. Moreover, total bilirubin
levels were consistently higher in the control
group compared to the retractor group
(p=0.008).
Immediately after surgery and on the first
postoperative day, direct bilirubin levels were
higher compared to the preoperative levels
(Figure 13), indicating a statistically significant
increase after surgery (p<0.001). However, no
significant differences were observed between
the groups (p=0.453).
Preoperative LDH levels were significantly
lower than postoperative and first postoperative
day levels (Figure 14), indicating a statistically
significant increase after surgery (p=0.032), with
partial normalization in the control group.
Additionally, LDH levels were significantly
higher in the retractor group compared to the
control group (p=0.007).
Coagulation markers also showed notable
changes. Immediately after surgery and on the
first postoperative day, INR levels were higher
compared to the preoperative levels (Figure 15),
indicating a statistically significant increase after
surgery (p<0.001). However, no significant
differences were observed between the groups
(p=0.158). In the control group, APTT levels
(Figure 16) varied significantly across all time
periods, initially showing a statistically
significant decrease followed by a significant
increase, whereas in the retractor group,
preoperative APTT levels were statistically
higher compared to postoperative levels.
Differences across time periods were statistically
significant (p=0.004), whereas no significant
differences were observed between the groups
(p=0.258).
Figure 2. Preoperative, postoperative and first postoperative day potassium levels in control and retractor group
PreC - preoperative control group values; PostC - immediate postoperative control group values; Post1C - first
postoperative day control group values; PreR - preoperative retractor group values; PostR - immediate
postoperative retractor group values; Post1R - first postoperative day retractor group values.
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Figure 3. Preoperative, postoperative and first postoperative day sodium levels in control and retractor group.
PreC - preoperative control group values; PostC - immediate postoperative control group values; Post1C - first
postoperative day control group values; PreR - preoperative retractor group values; PostR - immediate
postoperative retractor group values; Post1R - first postoperative day retractor group values.
Figure 4. Preoperative, postoperative and first postoperative day creatinine levels in control and retractor group.
PreC - preoperative control group values; PostC - immediate postoperative control group values; Post1C - first
postoperative day control group values; PreR - preoperative retractor group values; PostR - immediate
postoperative retractor group values; Post1R - first postoperative day retractor group values
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Figure 5. Preoperative, postoperative and first postoperative day urea levels in control and retractor group.
PreC - preoperative control group values; PostC - immediate postoperative control group values; Post1C - first
postoperative day control group values; PreR - preoperative retractor group values; PostR - immediate
postoperative retractor group values; Post1R - first postoperative day retractor group values
Figure 6. Preoperative, postoperative and first postoperative day C reactive protein levels in control and retractor
group.
PreC - preoperative control group values; PostC - immediate postoperative control group values; Post1C - first
postoperative day control group values; PreR - preoperative retractor group values; PostR - immediate
postoperative retractor group values; Post1R - first postoperative day retractor group values
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Figure 7. Preoperative, postoperative and first postoperative day alanine aminotransferase levels in control and
retractor group.
PreC - preoperative control group values; PostC - immediate postoperative control group values; Post1C - first
postoperative day control group values; PreR - preoperative retractor group values; PostR - immediate
postoperative retractor group values; Post1R - first postoperative day retractor group values
Figure 8. ROC curve analysis of surgery time as a prognostic marker for ALT elevation.
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Figure 9. Preoperative, postoperative and first postoperative day aspartate aminotransferase levels in control
and retractor group
PreC - preoperative control group values; PostC - immediate postoperative control group values; Post1C - first
postoperative day control group values; PreR - preoperative retractor group values; PostR - immediate
postoperative retractor group values; Post1R - first postoperative day retractor group values
Figure 10. ROC curve analysis of surgery time as a prognostic marker for aspartate aminotransferase elevation.
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Figure 11. ROC curve analysis of body mass index as a prognostic marker for aspartate and alanine
aminotransferase elevation.
Figure 12. Preoperative, postoperative and first postoperative day total bilirubin levels in control and retractor
group.
PreC - preoperative control group values; PostC - immediate postoperative control group values; Post1C - first
postoperative day control group values; PreR - preoperative retractor group values; PostR - immediate
postoperative retractor group values; Post1R - first postoperative day retractor group values
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Figure 13. Preoperative, postoperative and first postoperative day direct bilirubin levels in control and retractor
group.
PreC - preoperative control group values; PostC - immediate postoperative control group values; Post1C - first
postoperative day control group values; PreR - preoperative retractor group values; PostR - immediate
postoperative retractor group values; Post1R - first postoperative day retractor group values
Figure 14. Preoperative, postoperative and first postoperative day direct bilirubin levels in control and retractor
group.
PreC - preoperative control group values; PostC - immediate postoperative control group values; Post1C - first
postoperative day control group values; PreR - preoperative retractor group values; PostR - immediate
postoperative retractor group values; Post1R - first postoperative day retractor group values
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Figure 15. Preoperative, postoperative and first postoperative day international normalized ratio in control and
retractor group.
PreC - preoperative control group values; PostC - immediate postoperative control group values; Post1C - first
postoperative day control group values; PreR - preoperative retractor group values; PostR - immediate
postoperative retractor group values; Post1R - first postoperative day retractor group values
Figure 16. Preoperative, postoperative and first postoperative day activated partial thromboplastin time in the
control and retractor group
PreC - preoperative control group values; PostC - immediate postoperative control group values; Post1C - first
postoperative day control group values; PreR - preoperative retractor group values; PostR - immediate
postoperative retractor group values; Post1R - first postoperative day retractor group values
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4. Discussion
Our study assessed the impact of liver retractor
use on postoperative biochemical blood markers
changes specifically evaluating liver enzyme
elevations in patients undergoing laparoscopic
gastrofundoplication and gastric resection.
These findings were compared with existing
literature on postoperative liver enzyme
elevation across different types of surgeries.
Liver Enzyme Alterations and Surgical
Approach
Postoperative liver enzyme elevation,
particularly AST and ALT, were observed in our
study. Our findings demonstrated transient
hepatic enzyme elevations, aligning with
previous research indicating that such elevations
are more pronounced following laparoscopic
surgeries compared to open surgeries [15,16].
Several studies attribute these alterations to
multiple intraoperative factors, including direct
surgical manipulation of the liver during left lobe
retraction with various retractor types, patient
positioning, prolonged surgery duration and
increased intra-abdominal pressure due to
pneumoperitoneum. These factors can
compromise hepatic perfusion, leading to
transient hepatocellular injury [17-20].
A study comparing laparoscopic-assisted
gastrectomy (LAG) and open gastrectomy (OG)
found that while both surgical techniques
resulted in elevated liver enzyme levels, LAG
had a greater impact on AST and ALTelevation
on postoperative day 1, which gradually returned
to baseline by postoperative day 5 [17]. This
supports our findings of enzyme normalization
in the later postoperative period [13, 17]. Studies
have reported that both laparoscopic and robotic
gastrectomy are associated with postoperative
liver dysfunction, with robotic surgery being
identified as a potential risk factor due to
prolonged surgery time [13, 17]. However, we
did not include robotic procedures, making it
necessary for future studies to assess whether
robotic-assisted surgery presents a higher risk of
postoperative liver dysfunction in our patient
population.
Additionally, our study did not assess hepatic
artery ligation, which has been reported as a
contributing factor to postoperative liver enzyme
elevation [10, 17]. Previous research has
identified aberrant left hepatic artery ligation as
a significant risk factor for liver dysfunction
following gastric cancer surgery [10, 17]. The
absence of this variable in our analysis highlights
the need for future studies incorporating a
broader range of factors to better understand
their impact on postoperative liver function.
ROC Curve Analysis and Logistic Regression
To further detect significant risk factors for
postoperative liver enzyme elevation between
control and retractor group we performed
univariate analysis of covariance (ANCOVA).
Statistically significant variables were then
subjected to binary logistic regression analysis.
Surgery Duration as a Predictor
Our ROC curve analysis demonstrated that
surgery duration is a moderate predictor of AST
elevation, with an AUC of 0.683 (p=0.015). A
threshold of 95 minutes was identified, above
which patients had a sixfold increased likelihood
of AST elevation (OR = 6.26). Similarly, for
ALT elevation, the predictive value of surgery
duration was weaker (AUC=0.619, p=0.125),
with a threshold of 75 minutes. Surgeries lasting
longer than 75 minutes increased the likelihood
of ALT elevation by approximately 3.5 times
(OR=3.47). This suggests that AST may be more
sensitive to ischemic or mechanical stress during
prolonged procedures compared to ALT. Our
study results align with previous studies
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demonstrating a relationship between prolonged
operative time and AST, ALT elevation in
laparoscopic gastric surgeries [10, 19, 21].
Body Mass Index (BMI) and hepatocellular
damage
Unlike previous studies, our study did not find a
significant association between BMI and
postoperative AST or ALT elevation. Our ROC
curve analysis suggested that BMI was a weak
predictor, with an AUC of 0.623 for both
markers, and did not reach statistical
significance (p > 0.10). In contrast, prior
research has linked higher BMI to an increased
risk of postoperative hepatocellular damage,
particularly in minimally invasive procedures
[10, 17]. One potential explanation for this
discrepancy is the relatively homogenous BMI
distribution in our cohort, as well as differences
in patient selection criteria. Given the conflicting
evidence, further research is required to
determine whether BMI independently
contributes to postoperative liver enzyme
elevation or interacts with other factors such as
surgery duration and left liver lobe retraction.
Postoperative Laboratory Test Comparisons
Beyond hepatic enzyme elevations, our study
analyzed a broad panel of laboratory markers,
including total and direct bilirubin, lactate
dehydrogenase (LDH), coagulation parameters
(INR, aPTT), kidney function markers
(creatinine, urea), electrolytes (sodium,
potassium), and inflammatory markers such as
C-reactive protein (CRP). These findings
provide a comprehensive view of systemic
changes following laparoscopic surgery.
Bilirubin levels: In our study, direct bilirubin
levels increased postoperatively in both groups
but weren’t significantly higher in the control
group than in the retractor group. In contrast, a
significant elevation of total bilirubin level was
noted only in the control group postoperatively.
This finding aligns with previous research on
laparoscopic cholecystectomy, where bilirubin
elevations were observed postoperatively, with
studies attributing this to transient alteration of
hepatic perfusion [16, 22, 23]. However, others
suggest that these elevations are of limited
clinical significance and typically resolve within
days [16, 23, 24].
LDH changes: Our study revealed a significant
postoperative rise in LDH, with higher levels in
the retractor group compared to the control
group. This is consistent with previous studies
showing that LDH increases following
laparoscopic surgery [16, 23, 24], possibly due
to tissue hypoxia and hepatocellular stress from
increased intra-abdominal pressure [23].
Notably, some reports found a delayed increase
in LDH at 48 hours postoperatively , while
others described transient changes without
lasting clinical implications [23,24].
Coagulation markers (INR, aPTT): Our study
found a significant postoperative increase in
both INR and aPTT, though intergroup
differences were not significant. Elevated INR
levels following laparoscopic procedures have
been documented in the literature [25].
However, studies assessing coagulation changes
in laparoscopic surgery are limited, and further
research is needed to determine whether these
alterations are clinically relevant.
Inflammatory and kidney function markers: In
our study CRP was significantly elevated on the
first postoperative day, with higher levels in the
retractor group. This is consistent with literature
indicating that CRP increases postoperatively,
correlating with surgical trauma and systemic
inflammation [18, 26]. Additionally, we found
that while urea levels increased significantly
postoperatively in both groups, creatinine levels
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remained stable, suggesting that transient kidney
function changes may occur without significant
renal impairment.
These findings provide a broader perspective on
systemic physiological changes following
laparoscopic surgery. While most postoperative
changes are transient, further research is needed
to determine whether specific trends,
particularly in coagulation and inflammatory
markers, have prognostic significance in liver
dysfunction risk stratification.
Comparison of Control and Retractor
Groups
Our study included gastrofundoplication and
gastric resection in the retractor group, allowing
for a unique comparison with the control group.
While most previous studies focus on
gastrectomy or gastric bypass surgery, our
inclusion of fundoplication provides additional
insights. Studies analyzing colectomy patients as
controls for liver function comparisons suggest
that direct hepatic manipulation, rather than
pneumoperitoneum, plays a primary role in
enzyme elevations [22]. This aligns with our
findings that liver enzyme elevations were more
pronounced in patients undergoing gastric
surgery with retraction, emphasizing the
mechanical impact of retraction on hepatic
perfusion.
Study Limitations and Future Directions
While our study provides valuable insights into
postoperative hepatocellular damage and
laboratory test parameter changes, several
limitations must be considered. One major
limitation is the lack of robotic surgery data, as
robotic-assisted techniques are becoming more
prevalent, and future research should compare
liver function outcomes between laparoscopic
and robotic procedures. Additionally, our sample
size was relatively small, necessitating larger
studies to further evaluate the risks associated
with liver retractors. Another limitation is the
lack of long-term follow-up, as our study
focused on immediate postoperative changes;
therefore, future research should assess long-
term hepatic function, particularly in patients
with pre-existing liver disease. Furthermore,
certain potential contributors to liver
dysfunction, such as hepatic artery ligation,
anaesthetic drug or pneumoperitoneum effects,
were not analyzed in our study and should be
investigated in future research.
5. Conclusions
Our findings align with existing literature
demonstrating transient postoperative liver
enzyme elevations following laparoscopic
surgery. Differences in surgical technique, BMI
influence, and laboratory parameters highlight
the need for individualized perioperative
monitoring strategies. Further research should
expand on laboratory data analysis, compare
different surgical modalities, and assess the
impact of long-term hepatic function.
References
1. Vecchio R, MacFadyen BV, Palazzo F.
History of laparoscopic surgery. Panminerva
Med. 2000 Mar;42(1):87-90. PMID: 11019611.
2. Patil M Jr, Gharde P, Reddy K, Nayak
K. Comparative Analysis of Laparoscopic
Versus Open Procedures in Specific General
Surgical Interventions. Cureus. 2024 Feb
19;16(2):e54433. doi: 10.7759/cureus.54433.
PMID: 38510915; PMCID: PMC10951803.
3. Mohammadzade AR, Esmaili F.
Comparing Hemodynamic Symptoms and the
Level of Abdominal Pain in High- Versus Low-
Pressure Carbon Dioxide in Patients Undergoing
Laparoscopic Cholecystectomy. Indian J Surg.
Journal of Medical Sciences. 29 May, 2025 - Volume 13 | Issue 3. Electronic - ISSN: 2345-0592
109
2018 Feb;80(1):30-35. doi: 10.1007/s12262-
016-1552-4. Epub 2016 Oct 28. PMID:
29581682; PMCID: PMC5866798.
4. Shoar S, Naderan M, Ebrahimpour H,
Soroush A, Nasiri S, Movafegh A, Khorgami Z.
A prospective double-blinded randomized
controlled trial comparing systemic stress
response in Laparoscopic cholecystectomy
between low-pressure and standard-pressure
pneumoperitoneum. Int J Surg. 2016 Apr;28:28-
33. doi: 10.1016/j.ijsu.2016.02.043. Epub 2016
Feb 16. PMID: 26892713.
5. Tian, F., Sun, X., Yu, Y. et al.
Comparison of low-pressure and standard-
pressure pneumoperitoneum laparoscopic
cholecystectomy in patients with
cardiopulmonary comorbidities: a double
blinded randomized clinical trial. BMC Surg 24,
348 (2024).
6. Gupta R, Kaman L, Dahiya D, Gupta N,
Singh R. Effects of varying intraperitoneal
pressure on liver function tests during
laparoscopic cholecystectomy. J Laparoendosc
Adv Surg Tech A. 2013 Apr;23(4):339-42. doi:
10.1089/lap.2012.0399. Epub 2013 Feb 28.
PMID: 23448122.
7. Palanivelu P, Patil KP, Parthasarathi R,
Viswambharan JK, Senthilnathan P, Palanivelu
C. Review of various liver retraction techniques
in single incision laparoscopic surgery for the
exposure of hiatus. J Minim Access Surg. 2015
Jul-Sep;11(3):198-202. doi: 10.4103/0972-
9941.140202. PMID: 26195879; PMCID:
PMC4499926.
8. Vargas-Palacios A, Hulme C, Veale T,
Downey CL. Systematic Review of Retraction
Devices for Laparoscopic Surgery. Surg Innov.
2016 Feb;23(1):90-101. doi:
10.1177/1553350615587991. Epub 2015 May
29. PMID: 26025138.
9. Fersahoğlu MM, Ergin A, Çiyiltepe H,
Fersahoglu AT, Bulut NE, Bilgili AC, Kaya B,
Memişoğlu K. Comparison of the Pretzelflex
Retractor and Nathanson Retractor in
Laparoscopic Sleeve Gastrectomy Surgery.
Obes Surg. 2021 Nov;31(11):4963-4969. doi:
10.1007/s11695-021-05680-8. Epub 2021 Aug
26. PMID: 34436716.
10. Sano A, Saito K, Kuriyama K,
Nakazawa N, Ubukata Y, Hara K, Sakai M,
Ogata K, Fukasawa T, Sohda M, Fukuchi M,
Naitoh H, Shirabe K, Saeki H. Risk Factors for
Postoperative Liver Enzyme Elevation After
Laparoscopic Gastrectomy for Gastric Cancer.
In Vivo. 2021 Mar-Apr;35(2):1227-1234. doi:
10.21873/invivo.12373. PMID: 33622925;
PMCID: PMC8045111.
11. Gojayev A, Yüksel C, Mercan Ü,
Çaparlar MA, Cetindag O, Akbulut S, Ünal AE,
Bayar S, Demirci S. The effect and clinical
significance of using nathanson liver retractor on
liver function tests in laparoscopic gastric cancer
surgery. Pol Przegl Chir. 2021 Oct 17;94(1):54-
61. doi: 10.5604/01.3001.0015.3544. PMID:
35195072.
12. Hiramatsu K, Aoba T, Kamiya T,
Mohri K, Kato T. Novel use of the Nathanson
liver retractor to prevent postoperative transient
liver dysfunction during laparoscopic
gastrectomy. Asian J Endosc Surg. 2020
Jul;13(3):293-300. doi: 10.1111/ases.12735.
Epub 2019 Aug 7. PMID: 31389200; PMCID:
PMC7379723.
13. Sumiyoshi S, Kubota T, Ohashi T,
Nishibeppu K, Kiuchi J, Shimizu H, Arita T,
Yamamoto Y, Konishi H, Morimura R, Kuriu Y,
Shiozaki A, Ikoma H, Fujiwara H, Otsuji E. Risk
factors for liver dysfunction and their clinical
importance after gastric cancer surgery. Sci Rep.
2024 Apr 6;14(1):8076. doi: 10.1038/s41598-
Journal of Medical Sciences. 29 May, 2025 - Volume 13 | Issue 3. Electronic - ISSN: 2345-0592
110
024-58644-0. PMID: 38580718; PMCID:
PMC10997756.
14. Tamhankar AP, Kelty CJ, Jacob G.
Retraction-related liver lobe necrosis after
laparoscopic gastric surgery. JSLS. 2011 Jan-
Mar;15(1):117-21. doi:
10.4293/108680811X13022985131651. PMID:
21902957; PMCID: PMC3134686.
15. Kinjo, Y., Okabe, H., Obama, K.,
Tsunoda, S., Tanaka, E. and Sakai, Y. (2011),
Elevation of Liver Function Tests After
Laparoscopic Gastrectomy Using a Nathanson
Liver Retractor. World J Surg, 35: 2730-2738
1214. https://doi.org/10.1007/s00268-011-1301-
6
16. Sarma R, Ray S, Baishya NK, Sultana
W. Comparative Study of Levels of Serum
Bilirubin, Serum Transaminase, Serum Alkaline
Phosphatase, and Prothrombin Time After
Laparoscopic Cholecystectomy and Open
Cholecystectomy. Cureus. 2024 May
14;16(5):e60296. doi: 10.7759/cureus.60296.
PMID: 38872670; PMCID: PMC11170308.
17. Jeong GA, Cho GS, Shin EJ, Lee MS,
Kim HC, Song OP. Liver function alterations
after laparoscopy-assisted gastrectomy for
gastric cancer and its clinical significance.
World J Gastroenterol. 2011 Jan 21;17(3):372-8.
doi: 10.3748/wjg.v17.i3.372. PMID: 21253398;
PMCID: PMC3022299.
18. Midya S, Ramus J, Hakim A, Jones G,
Sampson M. Comparison of Two Types of Liver
Retractors in Laparoscopic Roux-en-Y Gastric
Bypass for Morbid Obesity. Obes Surg. 2020
Jan;30(1):233-237. doi: 10.1007/s11695-019-
04142-6. PMID: 31440956.
19. Fersahoğlu MM, Ergin A, Çiyiltepe H,
Fersahoglu AT, Bulut NE, Bilgili AC, Kaya B,
Memişoğlu K. Comparison of the Pretzelflex
Retractor and Nathanson Retractor in
Laparoscopic Sleeve Gastrectomy Surgery.
Obes Surg. 2021 Nov;31(11):4963-4969. doi:
10.1007/s11695-021-05680-8. Epub 2021 Aug
26. PMID: 34436716.
20. Goel R, Shabbir A, Tai CM, Eng A, Lin
HY, Lee SL, Huang CK. Randomized controlled
trial comparing three methods of liver retraction
in laparoscopic Roux-en-Y gastric bypass. Surg
Endosc. 2013 Feb;27(2):679-84. doi:
10.1007/s00464-012-2438-6. Epub 2012 Jul 7.
PMID: 22773237.
21. Kitajima T, Shinohara H, Haruta S,
Momose K, Ueno M, Udagawa H. Prevention of
transient liver damage after laparoscopic
gastrectomy via modification of the liver
retraction technique using the Nathanson liver
retractor. Asian J Endosc Surg. 2015
Nov;8(4):413-8. doi: 10.1111/ases.12200. Epub
2015 Jun 3. PMID: 26042554.
22. Kotake Y, Takeda J, Matsumoto M,
Tagawa M, Kikuchi H. Subclinical hepatic
dysfunction in laparoscopic cholecystectomy
and laparoscopic colectomy. Br J Anaesth. 2001
Nov;87(5):774-7. doi: 10.1093/bja/87.5.774.
PMID: 11878531.
23. Maleknia SA, Ebrahimi N. Evaluation
of Liver Function Tests and Serum Bilirubin
Levels After Laparoscopic Cholecystectomy.
Med Arch. 2020 Feb;74(1):24-27. doi:
10.5455/medarh.2020.74.24-27. PMID:
32317830; PMCID: PMC7164731.
24. Tan M, Xu FF, Peng JS, Li DM, Chen
LH, Lv BJ, Zhao ZX, Huang C, Zheng CX.
Changes in the level of serum liver enzymes after
laparoscopic surgery. World J Gastroenterol.
2003 Feb;9(2):364-7. doi:
10.3748/wjg.v9.i2.364. PMID: 12532468;
PMCID: PMC4611348.
25. Tsiminikakis N, Chouillard E, Tsigris
C, Diamantis T, Bongiorni C, Ekonomou C,
Journal of Medical Sciences. 29 May, 2025 - Volume 13 | Issue 3. Electronic - ISSN: 2345-0592
111
Antoniou C, Bramis I. Fibrinolytic and
coagulation pathways after laparoscopic and
open surgery: a prospective randomized trial.
Surg Endosc. 2009 Dec;23(12):2762-9. doi:
10.1007/s00464-009-0486-3. Epub 2009 May
15. PMID: 19444516.
26. Tamhankar AP, Kelty CJ, Jacob G.
Retraction-related liver lobe necrosis after
laparoscopic gastric surgery. JSLS. 2011 Jan-
Mar;15(1):117-21. doi:
10.4293/108680811X13022985131651. PMID:
21902957; PMCID: PMC3134686
Journal of Medical Sciences. 29 May, 2025 - Volume 13 | Issue 3. Electronic - ISSN: 2345-0592
112