Revista Argentina de Cirugía

Usefulness of microbiological bile analysis in grade II cholecystitis according to the Tokyo classification

2026-05-26T04:00:12+00:00

Background: The Tokyo Guidelines 2018 for the Management of Cholecystitis (TG18) recommend intraoperative microbiological bile analysis (MBA) in moderate cases (grades II) to identify microorganisms and adjust antibiotic therapy.
Objective: he aim of this study was to describe the results of samples obtained by intraoperative gallbladder aspiration for MBA and its association with comorbidities, PPI use, prior antibiotic therapy, and postoperative complications in patients with grade II cholecystitis.
Material and methods: This observational, prospective and descriptive study included adult patients (> 18 years) diagnosed with grade II acute cholecystitis according to the TG18 managed with laparoscopic cholecystectomy (LC). Patients were assigned to two groups based on a positive or negative MBA. The data analyzed included demographic variables, medical history, and surgical and microbiological characteristics. The chi-square test (χ²) was used to compare categorical variables. A p-value < 0.05 was considered statistically significant.
Results: Of the 272 patients who underwent LC, 51 had grade II acute cholecystitis; 29 (57%) were women, and mean age was 57 years (SD 18). The MBA was positive in 14 (27%) cases. Ten patients had a body mass index (BMI) of 25 or higher, 5 had comorbidities, and 7 used PPIs. None of the patients had received antibiotic therapy prior to hospitalization. E. coli was the most common germ involved (28%). All the germs were susceptible to ceftriaxone. There were no intraoperative adverse events resulting from gallbladder aspiration or postoperative complications.

Short-term outcomes of surgical treatment for retroperitoneal tumors over a 10-year period

2026-05-31T20:17:22+00:00

Background: Retroperitoneal tumors are uncommon, and their surgical removal poses a challenge for surgeons, as the space where they develop contains major blood vessels that are often compressed or displaced by the tumor. Sarcomas are the most common retroperitoneal tumors.
Objective: The aim of this study was to evaluate the short-term outcomes of surgical resection for retroperitoneal tumors.
Material and methods: We conducted an observational, retrospective and descriptive study. The medical records of patients who underwent surgery between January 2005 and December 2024 were reviewed. The demographic, clinical and operative variables were analyzed.
Results: A total of 12 patients underwent surgery; 8 had malignant lesions, 7 of which were sarcomas.
There were no deaths in the series and 4 patients developed in 4 cases (33%). Mean length of hospital stay was 6.5 days. An R0 resection confirmed by pathological examination was achieved in 9 patients. Three patients who could be followed up developed tumor recurrences.
Conclusion: Sarcomas were the most common retroperitoneal tumors. An R0 resection was achieved in most cases, with complication rates comparable to those reported in other series.

Soft tissue sarcomas of the extremities and trunk. Surgical and oncological outcomes in patients with local disease

2026-05-26T04:11:08+00:00

Background: Local soft tissue sarcomas (STS) of the extremities and superficial trunk require multimodal treatment to achieve local control rates > 80%.
Objective: The aim of this study was to describe the long-term surgical and oncological outcomes of patients with STS of the extremities and trunk with local disease.
Materials and methods: We conducted a retrospective, descriptive and observational study of patients with STS of the extremities and trunk who underwent surgery between 2008 and 2024. Patients were divided into 3 groups: primary tumors (G!), local recurrences (G2) and margin widening following inadequate resections (G3). The clinical and pathological characteristics, type of resection and reconstruction, complications, and adjunctive treatment therapy were recorded. Local recurrence-free survival (LRFS) and overall survival (OS) were evaluated in each group.
Results: A total of 124 patients were included: 61 (49%) in group 1, 37 (30% in group 2, and 26 (21%) in group 3. Median tumor size was 8.5 cm (IQR 3.25-12). All the tumors were completely resected with limb preservation in 98.8%. Reconstructive procedures were performed in 36 cases (29%), with a higher incidence in groups G2 and G3. Radiation therapy was administered to 22 patients in G1, 6 as neoadjuvant therapy and 16 as adjuvant therapy. In G1, 5-year LRFS, distant metastases and OS were 82.8%, 63.5%, and 79.3%, respectively. In G2 and G3, the rates were 61.6%, 75%, and 85.3%.

Artificial intelligence-based chatbots: the importance of asking the right questions

2026-06-26T13:16:32+00:00

Background: Artificial intelligence-based chatbots (CBIA) are a widely used source of medical information. Prompt engineering (PE) focuses on designing and optimizing the questions asked of AI/ CBs to improve responses.
Objective: The aim of this study was to compare the quality of prompts and the responses provided by an AiCB for clinical case resolution in general surgery, before and following PE training.
Materials and methods: Three fictional clinical cases were developed for residents in general surgery to solve using ChatGPT-4®. After they were trained in PE, the participants solved the cases again. The quality of the prompts was evaluated using a scale (5-15 points) that explored completeness, context, input data, output format, and instructions. The chatbot’s answers were assessed using a scale (3- 15 points) that included accuracy, completeness, and relevance. The results obtained before and following PE training were compared.
Results: Sixteen postgraduate year 1 to 4 residents participated in the study. The quality of prompts improved significantly following PE training, as assessed by total score [7.9 (1.8) vs. 10.4 (2.1), p< 0.01] for completeness, context, data input, and output format categories. Chatbot’s responses also improved across the categories and total score [10.2 (2) vs. 11.9 (1.8), p<0.01].
Conclusion: Training in PE significantly improved the quality of prompts and AiCB’s responses for solving general surgery clinical cases.

Accuracy of artificial intelligence for staging and decision-making in esophageal and gastric cancer

2026-06-29T21:59:31+00:00

Background: Artificial intelligence (AI) has demonstrated increasing potential in oncology, including in imaging analysis and as a tool for supporting clinical decision-making.
Objective: The aim of this study was to evaluate an AI conversational model, trained using up-to-date clinical guidelines, to assist with staging and initial treatment planning in patients with gastroesophageal cancer.
Materials and methods: We conducted a retrospective study of patients with esophageal, gastric, and gastroesophageal junction cancer treated at a tertiary care hospital between December 2023 and May 2025. A virtual clinical assistant or chatbot was developed using ChatGPT-4.5® (OpenAI), configured to interpret test results in accordance with the NCCN and ESMO guidelines. The chatbot was designed to determine the clinical stage (cTNM), suggest a treatment plan, and identify relevant findings. The answers were compared with the decisions made by the treating physician.
Results: Of the 53 patients evaluated, 34 met the inclusion criteria. The accuracy between the cTNM staging determined by the medical team and that of the chatbot was 94%. The concordance in the suggested therapeutic approach was 85%. The discrepancies were due to differences in the interpretation of the stage, clinical considerations not available to the AI, and social or logistical factors that influenced the medical decision.
Conclusion: AI, implemented through a chatbot trained using clinical guidelines, proved useful in supporting staging and initial treatment planning for gastroesophageal cancer, with high concordance with clinical decisions.

The importance of asking the right questions: prompt engineering and language models in clinical practice

2026-06-29T21:54:24+00:00

Accuracy, staging, and decision-making: artificial intelligence in gastroesophageal cancer

2026-06-29T21:56:49+00:00

Sample size in surgical research

2026-06-26T13:40:14+00:00

Sample size calculation is an essential component of the methodological design in medical research. In scientific studies, reporting the sample size improves the interpretability of the results, strengthening both the internal validity and ethical legitimacy of the study. This aspect is particularly important in surgery, given that many clinical events are relatively rare and surgical techniques can vary considerably from surgeon to surgeon.

Partial bowel obstruction caused by intussusception as a late complication following Roux-en-Y gastric bypass surgery

2026-06-26T13:23:28+00:00

Intussusception is more common in pediatric patients, and its incidence in adults is low, typically associated with diverticula, polyps, tumors, or a history of previous surgeries. Early surgical intervention is considered the treatment of choice. A 44-year-old female patient with a history of Roux-en-Y gastric bypass is admitted with a clinical diagnosis of partial bowel obstruction, suggestive of intussusception based on computed tomography scan findings. An exploratory laparoscopy was performed for diagnostic and therapeutic purposes. An invaginated segment of the alimentary loop was found 10 centimeters from the base of the Roux-en-Y anastomosis, with preserved blood supply and motility,
and was reduced. The postoperative period was uneventful, and the patient was discharged 48 hours after the procedure. There were no late complications. Laparoscopy is considered the preferred approach because it offers better postoperative outcomes, reduced postoperative ileus, a faster return to work, reduced pain, and enhanced cosmetic results compared to the conventional approach.

Encapsulating peritoneal sclerosis: a case report of cocoon syndrome, an unusual cause of bowel obstruction

2026-06-26T13:31:51+00:00

Encapsulating peritoneal sclerosis (EPS), also known as cocoon syndrome, is a rare cause of bowel
obstruction in which the small intestine is encased by a thin fibrous membrane. We report the case of
a 76-year-old male patient with no history of abdominal surgery who presented with colicky abdominal pain, vomiting, and abdominal distension. A computed tomography (CT) scan revealed severe bowel obstruction. During surgery, loops of the ileum were found to be encased in fibrous tissue, confirming a type II EPS. The adhesions were released and intraoperative intestinal perforations were repaired. The patient evolved with favorable outcome. The diagnosis is often complex and is frequently confirmed during surgery. A CT scan helps guide treatment by revealing dilated loops and thickened membranes.
There are no standardized international guidelines. In cases of obstruction, surgery is the treatment of choice. This case highlights the importance of considering EPS in patients with no history of surgery.

Liver Transplantation for Unresectable Perihilar Cholangiocarcinoma: A Case Report Following a Strict Oncologic Selection Protocol

2026-06-29T22:07:53+00:00

Perihepatic cholangiocarcinoma (pCCA) is one of the most challenging hepatobiliary tumors to treat in terms
of surgical complexity and poor prognosis in unresectable cases. In selected patients without metastatic
disease, liver transplantation (LT) performed according to a protocol that includes neoadjuvant therapy
has emerged as an accepted curative option. We present the case of a 52-year-old man with unresectable
pCCA due to bilateral vascular involvement, who was treated according to a strict institutional protocol that included neoadjuvant chemoradiotherapy and orthotopic liver transplantation. Despite recurrent episodes of cholangitis during follow-up, tumor markers remained normal, and a staging laparoscopy ruled out distant metastases. Cadaveric liver transplantation was successfully performed without significant intraoperative complications. This case demonstrates the feasibility and favorable outcomes of standardized transplantation for unresectable pCCA, supporting its implementation in specialized centers with carefully selected patients. Liver transplantation following a protocol offers the possibility of prolonged survival in cases where curative options have historically been unavailable.

External mandibular fixation in maxillofacial gunshot injury

2026-06-29T22:17:09+00:00

Maxillofacial gunshot injuries constitute a clinical challenge due to the complex anatomy and high risk of morbidity and mortality. Comminuted mandibular fractures resulting from ballistic trauma are often associated with bone loss, bacterial infection, and extensive soft tissue damage, limiting the use of open reduction with rigid internal fixation. We present the case of a 19-year-old male patient with a comminuted mandibular fracture caused by a bullet, managed with external fixation with bicortical Kirschner wires, a silicone tube, and self-curing acrylic resin. The technique enabled the stabilization of the bone fragments without the necessity for extensive approaches, thereby preserving the periosteal blood supply and reducing the risk of complications.
External fixation constitutes an effective and low-cost alternative for managing complex mandibular fractures, particularly in patients with polytrauma or involvement of other tissues. This method serves as both a definitive treatment and a bridging treatment for future reconstruction.