Clinical significance of appendicoliths in elderly patients over eighty years old undergoing emergency appendectomy: A single-center retrospective study

Abstract

BACKGROUND

Acute appendicitis with an appendicolith is one of the most common abdominal emergencies in elderly patients and is more likely to progress to gangrene and perforation.

AIM

To analyze the clinical data of elderly patients undergoing emergency appendectomy for acute appendicitis, aiming to improve treatment strategies.

METHODS

The clinical data of 122 patients over 80 years old who underwent emergency appendectomy for acute appendicitis at the Department of Emergency Surgery of Zhongshan Hospital, Fudan University from January 2016 to March 2023 were retrospectively analyzed. The patients were divided into two groups based on the presence of an appendicolith or not, and clinicopathological and surgery-related features were compared between the two groups.

RESULTS

The duration of abdominal pain in all 122 patients ranged from 5 to 168 h. All patients underwent emergency appendectomy: 6 had an open appendectomy, 101 had a laparoscopic appendectomy, and 15 required conversion from laparoscopic to open surgery, resulting in a conversion rate of 12.9% (15/116). The patients were divided into two groups: Appendicolith group (n = 46) and non-appendicolith group (n = 76). Comparisons of clinicopathological features revealed that patients with appendicoliths were more likely to develop appendiceal gangrene (84.8% vs 64.5%, P = 0.010) and perforation (67.4% vs 48.7%, P = 0.044), and had a lower surgical conversion rate (2.2% vs 19.7%, P = 0.013). The median length of hospital stay was 5.0 d for both groups and there was no significant difference between them. All patients were successfully discharged.

CONCLUSION

Around 40% of patients over 80 years old with acute appendicitis have an appendicolith, increasing their risk of developing appendiceal gangrene and perforation, and therefore should receive timely surgical treatment.

Key Words: Elderly patients; Acute appendicitis; Appendicolith; Appendectomy; Acute abdomen

Core Tip: Acute appendicitis is increasingly a common cause of abdominal pain among elderly patients in China. Although antibiotic therapy has become the primary treatment for acute uncomplicated appendicitis, elderly patients experience significantly higher rates of postoperative complications. Our study revealed that about 40% of these elderly patients had an appendicolith, which put them at a higher risk for appendiceal gangrene and perforation. This finding emphasizes the necessity for timely surgical intervention in these cases.

INTRODUCTION

The elderly population in China is growing. Influenced by social determinants of health, such as education, economic stability, community safety, and healthcare advancements, the average life expectancy in China increased to 78.2 years in 2021[1]. As a result, acute appendicitis has become a prevalent cause of abdominal pain in elderly patients[1]. Appendicitis is most commonly caused by the obstruction of the appendiceal lumen by appendicoliths[2]. However, in rare cases, luminal obstruction may result from neuroendocrine tumors[3], intestinal parasitic infestations such as Enterobius vermicularis[4], or foreign bodies[5]. The epidemiology and outcomes of acute appendicitis in elderly individuals differ significantly from those in younger individuals[6]. In elderly patients, acute appendicitis has a much higher mortality rate, up to 8% for those older than 65 years, compared to a 0% to 1% mortality rate in younger patients[7]. Moreover, nearly all studies agree that elderly patients are significantly more prone to complicated appendicitis with perforation or abscess[8]. The rate of complicated appendicitis in elderly patients ranges from 18% to 70%, whereas in younger patients, it ranges from 3% to 29%[9,10]. Additionally, the rate of accurate preoperative diagnosis is lower in elderly patients, with a diagnostic accuracy of 64% for those older than 65 years, compared to 78% in younger populations[11].

Although antibiotic therapy has become the preferred treatment approach for acute uncomplicated appendicitis, elderly patients with acute appendicitis face unique challenges[12]. Due to decreased physiological response and reduced immune function, elderly patients often experience delayed symptom onset, lower diagnostic accuracy, and a greater incidence of appendiceal gangrene and perforation[13,14]. This leads to a significantly greater rate of postoperative complications. Additionally, elderly patients often have comorbid conditions such as heart disease, hypertension, and diabetes, which significantly increase the perioperative safety demands on emergency surgeons[15]. Therefore, careful consideration is crucial when treating elderly patients diagnosed with acute appendicitis.

In this study, we examined the clinicopathological features of patients over the age of 80 who underwent emergency appendectomy for acute appendicitis and explored their correlation with the presence of an appendicolith. The findings indicated that elderly patients with acute appendicitis who also had an appendicolith were more likely to develop appendiceal gangrene and perforation. These patients should receive timely surgical treatment to mitigate these risks.

MATERIALS AND METHODS

Study design and patients

We prospectively recruited consecutive patients with acute appendicitis, collected their clinicopathological data, and retrospectively analyzed the clinicopathological features correlated with prognosis to improve treatment strategies. Between January 2016 and March 2023, 3896 patients underwent emergency appendectomy at the Department of Emergency Surgery, Zhongshan Hospital, Fudan University (Shanghai, China). The analytical data included general patient information (e.g., age, sex, and body temperature), clinical manifestations (e.g., pain location, nausea, and vomiting), past history, comorbidities (e.g., diabetes, hypertension, and coronary heart disease), preoperative blood test results [e.g., white blood cell (WBC) count and percentage of neutrophils], imaging examination results [e.g., computed tomography (CT) findings], surgical approach, length of hospital stay, and prognosis. All patients with acute appendicitis underwent a CT scan of the abdomen and pelvis upon arrival at the emergency department. The presence of appendicoliths and appendiceal perforation was typically diagnosed using a combination of preoperative imaging, intraoperative findings, and postoperative examination. Preoperative CT scans may show extraluminal air, abscesses, fluid collections, or an appendiceal wall defect. Intraoperatively, surgeons may observe a perforation, pus, abscess, or signs of peritonitis, along with necrosis or gangrene of the appendix. Postoperatively, examination of the specimen can reveal macroscopic perforation or necrosis, which may be further confirmed by histopathological analysis. Patients were divided into two groups based on the presence of an appendicolith or not, and clinicopathological and surgery-related features were compared between the two groups (Figure 1). The Clinical Research Ethics Committee of Zhongshan Hospital, Fudan University (Shanghai, China) granted ethical approval for this study. Informed consent was obtained from all patients for the collection and use of anonymized clinical data.

Figure 1 Flowchart of inclusion process of patients. CT: Computed tomography.

Inclusion and exclusion criteria

This retrospective study included patients who met the following criteria: Aged 80 years or older, received conservative treatment for less than 24 h before surgery, had no peri-appendiceal abscess larger than 2 cm in diameter on CT scan, underwent emergency appendectomy, and had postoperative pathological confirmation of acute appendicitis. Patients younger than 80 years, those with malignancies, and those with incomplete clinical or pathological records were excluded from the study. Based on these criteria, the study included 122 elderly patients aged 80 years and older, consisting of 63 males and 59 females, aged between 80 and 96 years, with a median age of 84 years.

Primary and secondary endpoints

The primary endpoint of this study was to assess the clinical significance of appendicoliths in elderly patients over 80 years old undergoing emergency appendectomy. This included examining the correlation between the presence of appendicoliths and the surgical approach used, as well as the incidence of postoperative complications, such as surgical site infections (SSI) and incisional hernias. The secondary endpoints focused on the association of appendicoliths with appendiceal gangrene, perforation, peri-appendiceal abscess formation, and length of hospital stay. Discharge criteria included symptom resolution (e.g., pain and fever), stable vital signs, tolerance of oral intake, normalization of laboratory parameters (e.g., WBC count), and the absence of postoperative complications.

Statistical analysis

Statistical analyses were conducted using SPSS Software (version 27.0; SPSS Inc., Chicago, IL, United States). Skewed data are reported as the median with interquartile range. Categorical variables are presented as counts and percentages. Differences in distributions were evaluated using Pearson’s χ² test or Fisher’s exact test for categorical variables, and Student’s t-test for continuous variables. A P value of < 0.05 was considered statistically significant.

RESULTS

Baseline characteristics

In this study, all 122 patients presented to the emergency department with abdominal pain lasting between 5 and 168 h (median: 37 h). Among them, 31 patients (25.4%) had periumbilical pain, 22 (18.0%) experienced upper abdominal pain, and 69 (56.6%) had right lower abdominal pain. Nausea was noted in 42 patients (34.4%) and vomiting was noted in 29 (23.8%). At presentation, 31 patients (25.4%) had a body temperature ≥ 38 °C. WBC counts were ≥ 15 × 10⁹/L in 32 patients (26.2%) and < 9.5 × 10⁹/L in 29 (23.8%), while the percentage of neutrophils was ≥ 90% in 37 patients (30.3%). Preoperative CT revealed an appendicolith in 46 patients (37.7%).

All patients received routine antibiotic therapy (second-generation cephalosporins + metronidazole) before surgery. The comorbidities included diabetes in 19 patients, hypertension in 71, and coronary heart disease in 36. Additionally, 3 patients had a history of rectal cancer surgery, 2 had previous stomach surgery, and 1 had a history of small intestine surgery (Table 1).

Table 1 Baseline characteristics of the patients.

Factor	n	%
All patients	122	100
Sex
Female	59	48.4
Male	63	51.6
Pain location
Periumbilical pain	31	25.4
Upper abdominal pain	22	18.0
Right lower abdominal pain	69	56.6
Nausea and vomiting
Nausea	42	34.4
Vomiting	29	23.8
Nausea + vomiting	42	34.4
Body temperature
< 38 °C	91	74.6
≥ 38 °C	31	25.4
WBC count
< 9.5 × 109/L	29	23.8
9.5-15 × 109/L	61	50.0
≥ 15 × 109/L	32	26.2
Percentage of neutrophils
< 90%	85	69.7
≥ 90%	37	30.3
Comorbidities
Diabetes	19	15.6
Hypertension	71	58.2
Coronary heart disease	36	29.5
Previous surgery
Rectal cancer surgery	3	2.6
Stomach surgery	2	1.6
Small intestine surgery	1	0.8
CT scan
Appendicolith	46	37.7

WBC: White blood cell; CT: Computed tomography.

Emergency appendectomy and postoperative complications

All patients underwent emergency appendectomy. Among them, 6 patients with a history of abdominal surgery underwent an open appendectomy. Laparoscopic appendectomy was performed on 101 patients, while 15 patients required conversion from laparoscopic to open appendectomy due to severe peri-appendiceal adhesions, resulting in a conversion rate of 12.9% (15/116).

Intraoperative examination revealed appendiceal gangrene in 87 patients (71.3%), perforation in 68 (55.7%), and peri-appendiceal abscess formation in 17 (13.9%). Pathology reports confirmed acute appendicitis in all patients, with 6 patients (4.9%) with acute simple appendicitis, 29 (23.8%) with acute suppurative appendicitis, and 87 (71.3%) with acute gangrenous appendicitis.

SSI were observed in 9 patients (7.3%), comprising 6 (4.9%) with superficial incisional SSI, 2 (1.6%) with deep incisional SSI, and 1 (0.8%) with organ or space SSI. Additionally, 7 patients (5.7%) developed postoperative pneumonia. The length of hospital stay ranged from 2 to 17 d, with a median stay of 5 d. All patients were successfully discharged, with no perioperative deaths (Table 2).

Table 2 Surgery related factors of the patients.

Factor	n	%
All patients	122	100
Surgery method
Laparoscopic appendectomy	101	82.8
Conversion to open appendectomy	15	12.3
Open appendectomy	6	4.9
Pathology
Acute simple appendicitis	6	4.9
Acute suppurative appendicitis	29	23.8
Acute gangrenous appendicitis	87	71.3
Appendiceal gangrene
Yes	87	71.3
No	35	28.7
Appendiceal perforation
Yes	68	55.7
No	54	44.3
Peri-appendiceal abscess
Yes	17	13.9
No	105	86.1
SSI
Superficial incisional SSI	6	4.9
Deep incisional SSI	2	1.6
Organ or space SSI	1	0.8
Postoperative pneumonia	7	5.7
Length of hospital stays, median (IQR) (days)	5.0 (4.0-7.0)

SSI: Surgical site infections; IQR: Interquartile range.

Correlations between clinicopathological factors and appendicoliths

Preoperative abdominal and pelvic CT scans identified an appendicolith in 46 patients (37.7%). Patients were categorized into two groups based on the presence of appendicoliths or not: Appendicolith group (n = 46) and non-appendicolith group (n = 76). An analysis of clinical and pathological factors revealed no significant correlation between the presence of an appendicolith and variables such as age, sex, preoperative body temperature, pain location, clinical symptoms, blood test results, or comorbidities (Table 3).

Table 3 Correlation between clinicopathological factors and appendicolith.

Factor	Appendicolith		P value
	Yes	No
All patients	46	76
Age (years)1			0.961
< 84	22	36
≥ 84	24	40
Sex			0.157
Female	27	32
Male	19	44
Pain location			0.514
Periumbilical pain	9	22
Upper abdominal pain	9	13
Right lower abdominal pain	28	41
Nausea			0.265
Yes	13	29
No	33	47
Vomiting			0.977
Yes	11	18
No	35	58
Body temperature			0.155
< 38 °C	31	60
≥ 38 °C	15	16
WBC count			0.592
< 9.5 × 109/L	9	20
9.5-15 × 109/L	23	38
≥ 15 × 109/L	14	18
Percentage of neutrophils			0.405
< 90%	30	55
≥ 90%	16	21
Diabetes			0.667
Yes	8	11
No	38	65
Hypertension			0.770
Yes	26	45
No	20	31
Coronary heart disease			0.861
Yes	14	22
No	32	54

¹Split at median.

WBC: White blood cell.

Correlations between surgical factors and appendicoliths

Further analysis revealed that patients with an appendicolith had a significantly greater likelihood of developing appendiceal gangrene (84.8% vs 64.5%, P = 0.010) and perforation (67.4% vs 48.7%, P = 0.044). However, there were no significant correlation between the presence of an appendicolith and other factors such as peri-appendiceal abscess, surgical site infection, and pneumonia. In addition, the median length of hospital stay was 5.0 d for both groups (with and without appendicoliths) and there was no significant difference between them. Notably, the presence of an appendicolith was associated with a lower surgical conversion rate (2.2% vs 19.7%, P = 0.013; Table 4).

Table 4 Correlation between surgical factors and appendicolith, n (%).

Factor	Appendicolith		P value
	Yes	No
Surgery method			0.013a
Laparoscopic appendectomy	44	57
Conversion to open appendectomy	1	14
Open appendectomy	1	5
Pathology			0.199
Acute simple appendicitis	1	5
Acute suppurative appendicitis	6	23
Acute gangrenous appendicitis	39	48
Appendiceal gangrene			0.010a
Yes	39	48
No	7	28
Appendiceal perforation			0.044a
Yes	31	37
No	15	39
Peri-appendiceal abscess			0.391
Yes	8	9
No	38	67
SSI			0.223
Superficial incisional SSI	4	2
Deep incisional SSI	1	1
Organ or space SSI	1	0
Postoperative pneumonia	4 (8.7)	3 (3.9)	0.274
Length of hospital stays, median (IQR) (d)	5.0 (4.0-7.0)	5.0 (4.0-7.5)	0.957

^aP < 0.05.

SSI: Surgical site infections; IQR: Interquartile range.

DISCUSSION

As the average life expectancy in China approaches 80 years, the number of patients over 80 years old presenting with acute appendicitis is steadily increasing, making it a significant cause of abdominal pain in this age group[1]. However, according to most studies, elderly patients have a lower rate of accurate preoperative diagnosis of acute appendicitis than younger patients[16]. Elevated inflammatory markers such as WBC count, C-reactive protein, and procalcitonin are common indicators of bacterial infections and the resultant inflammatory response[17]. Approximately 80% of acute appendicitis patients exhibit leukocytosis and a shift in the neutrophil count to the left[18,19]. However, elderly individuals often have a blunted inflammatory response, resulting in less pronounced laboratory and physical findings[13,20]. In addition, elderly patients frequently have comorbidities such as hypertension, coronary heart disease, chronic obstructive pulmonary disease, and diabetes[15]. These conditions compromise the organ reserve, reduce tolerance to surgery, and increase perioperative risks. A large Swedish study revealed that the case fatality rate after appendectomy was strongly influenced by age, with a threefold increase for each decade of age, reaching more than 16% in nonagenarians[21]. In this study, fewer than one-third of patients had WBC counts ≥ 15 × 10⁹/L, and nearly one-quarter had normal WBC counts, indicating a lower sensitivity of routine blood tests for diagnosing acute appendicitis in those over 80 years of age. Therefore, a comprehensive assessment combining patient medical history and auxiliary medical examinations is essential. Additionally, due to a decline in immune function in elderly patients, infections can progress rapidly, necessitating aggressive perioperative anti-infective treatment, including broad-spectrum antibiotics covering Gram-positive, Gram-negative, and anaerobic bacteria[22].

Early diagnosis and prompt surgical intervention remain the cornerstones of managing acute appendicitis[23]. Although antibiotic therapy has become a mainstay for treating uncomplicated appendicitis, there is no final conclusion on the conservative treatment of complicated appendicitis[9]. Elderly patients often have appendiceal artery atherosclerosis, making them more prone to appendiceal ischemia and necrosis when acute appendicitis occurs[24]. In addition to vascular sclerosis in the vermiform appendix, factors such as luminal narrowing due to fibrosis, fat infiltration of the muscular layers, and structural weakness contribute to a greater tendency for early perforation[25]. These factors, along with delays in diagnosis and treatment, may explain the more aggressive progression of the disease in elderly patients. A large observational study of 164579 patients with acute appendicitis identified age over 65 years as a significant risk factor for mortality in multivariate analysis[26]. In this study, more than 70% of the elderly patients had acute gangrenous appendicitis (87/122), and more than 50% had appendiceal perforation (68/122). Approximately 25% of acute appendicitis cases are associated with an appendicolith, which increases the risk of complicated appendicitis and often results in failed conservative treatment with more complications[27]. Nearly 40% of the elderly patients in this study had appendicoliths, significantly higher than average. Patients with an appendicolith were more likely to develop gangrene and perforation, with over 80% of patients in the appendicolith group experiencing acute gangrenous appendicitis compared to 63.2% in the non-appendicolith group. In addition, elderly patients often delay seeking medical care, resulting in a greater perforation rate at presentation[28]. These findings underscore the importance of prompt surgical intervention in elderly patients with acute appendicitis to prevent the progression to diffuse peritonitis due to appendiceal gangrene and perforation. Despite the increased risk of gangrene and perforation in patients with an appendicolith, timely surgery can achieve similar outcomes to those without an appendicolith.

The introduction of conservative treatment as an option for acute appendicitis has raised questions about the timing of surgery and the potential consequences of delaying surgical intervention[29]. Furthermore, operating rooms are not available around the clock in all hospitals. On the one hand, initial conservative treatment could reduce the rate of negative explorations; on the other hand, some authors suggest that surgical treatment could be delayed for patients misdiagnosed with free perforated appendicitis, leading to worse outcomes[10]. This is particularly concerning for elderly patients, who have a higher rate of perforation and more challenging diagnoses than children and adults. Therefore, for elderly patients, it is crucial to promptly conduct comprehensive examinations and initiate conservative treatments, including prophylactic antibiotics and maintenance of fluid and electrolyte balance, after the patient arrives at the emergency department. Timely consultations with cardiology and other relevant departments for comorbid conditions are essential. Once acute appendicitis is confirmed, prompt appendectomy and stringent perioperative management of comorbidities are necessary to improve outcomes.

Laparoscopic appendectomy has become the preferred treatment for acute appendicitis due to its minimal invasiveness, thorough intra-abdominal exploration, minimal disruption to abdominal organs, fewer complications, and faster postoperative recovery[30]. Guidelines for adult patients recommend the laparoscopic approach for all patients, including those with complicated acute appendicitis[10]. In elderly patients, the likelihood of concurrent malignant neoplasms increases, making laparoscopic exploration valuable for ensuring that these conditions are not overlooked[31]. Additionally, elderly patients may present with right lower abdominal pain due to conditions such as colonic diverticulosis, redundant colon, or other diseases, which can be clarified through laparoscopic exploration[32]. However, insufflation of carbon dioxide during laparoscopic surgery can increase abdominal pressure and affect pulmonary function. Therefore, in elderly patients, it is crucial to minimize intra-abdominal CO₂ pressure to reduce physiological disturbances[30]. In this study, the postoperative pneumonia rate was approximately 6%, and all patients were successfully managed with aggressive anti-infective and supportive treatments. In elderly patients with paralytic ileus, the possibility of appendicitis should also be considered[33]. Paralytic ileus may result from appendiceal perforation and diffuse peritonitis, necessitating a thorough history, physical examination, and diagnostic workup to avoid missed diagnoses[33]. Once acute appendicitis is confirmed, prompt laparoscopic exploration or, if necessary, open surgery is required to thoroughly clear the abdominal infection and prevent residual infection.

There are several limitations to this study. First, as a retrospective analysis, it may be prone to selection biases, despite utilizing data from a prospectively recruited database. Second, the absence of long-term follow-up data on patients who underwent emergency appendectomy means that we were unable to assess long-term outcomes, such as quality of life and the development of late complications, which are critical for understanding the full impact of the treatment strategies employed. Third, the sample size in this study was relatively small, which may limit the statistical power and the ability to detect subtle but clinically significant differences between groups. Lastly, this study did not account for numerous subjective factors, including patient preferences and socio-cultural influences, which can have a substantial effect on treatment outcomes. These factors, particularly in the context of elderly patients in China, may be as important as the objective clinical factors and should be considered in future studies to provide a more comprehensive understanding of treatment outcomes.

CONCLUSION

Acute appendicitis is a significant cause of abdominal pain in patients over 80 years old. About 40% of these elderly patients had an appendicolith, which put them at a higher risk for appendiceal gangrene and perforation. This finding emphasizes the necessity for timely surgical intervention to optimize the prognosis for these patients.