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Papers by Theodoros Kontoulis

Research paper thumbnail of Preventing intraperitoneal adhesions with atorvastatin and sodium hyaluronate/carboxymethylcellulose: a comparative study in rats

The American Journal of Surgery, 2010

OBJECTIVES: The aim of this study was to compare the effectiveness of atorvastatin with the sodiu... more OBJECTIVES: The aim of this study was to compare the effectiveness of atorvastatin with the sodium hyaluronate/carboxymethylcellulose (HA/CMC, Seprafilm; Genzyme; Genzyme Biosurgery Corporation, Cambridge, MA) in preventing postoperative intraperitoneal adhesion formation in rats.

Research paper thumbnail of Management of Ingested Foreign Bodies. How Justifiable is a Waiting Policy?

Surgical Laparoscopy, Endoscopy & Percutaneous Techniques, 2008

Foreign body ingestion is a commonly seen accident in emergencies, usually in children (80%), eld... more Foreign body ingestion is a commonly seen accident in emergencies, usually in children (80%), elderly, mentally impaired, or alcoholic individuals, whereas it may occur intentionally in prisoners or psychiatric patients. According to the literature, 90% of ingested foreign bodies pass through the gastrointestinal tract without complications, 10% to 20% necessitate endoscopic removal, whereas only 1% of them will finally need surgical intervention. In clinical practice, we often face the dilemma of choosing the appropriate treatment modality. We present 13 cases treated in our department, emphasizing in a "waiting and close observation" policy. Among these cases, only 1 patient needed to be operated because of obstruction of ileocecal valve by a large coin. Indications for treatment where applicable are also being discussed.

Research paper thumbnail of Laparoscopic cholecystectomy in patients with previous upper or lower abdominal surgery

Research paper thumbnail of A Rare Case of Malignant Triton Tumor with Pluridirectional Differentiation

Southern Medical Journal, 2009

An enlarging soft tissue mass was resected from the leg of a young man with neurofibromatosis typ... more An enlarging soft tissue mass was resected from the leg of a young man with neurofibromatosis type 1. Rhabdomyosarcomatous elements admixed with islands of osteoid and chondroid matrix was seen on microscopy. Based on immunohistochemistry, a malignant triton tumor, an uncommon subtype of peripheral nerve sheath tumor with rhabdomyosarcomatous elements, was diagnosed. The important feature of this neoplasm was that it showed pluridirectional differentiation to osteosarcoma and chondrosarcoma. This pathologic finding is rare and seen in only a few cases of all malignant triton tumors.

Research paper thumbnail of The Oxidative Effect of Prolonged CO2 Pneumoperitoneum A Comparative Study in Rats

Journal of Surgical Research, 2012

The current study evaluated the effect of time in the severity of the oxidative stress due to pne... more The current study evaluated the effect of time in the severity of the oxidative stress due to pneumoperitoneum. Forty Wistar rats were allocated randomly into 2 groups. The 1 h pneumoperitoneum (Pp) group, which was subjected to 60 min of pneumoperitoneum, and the 3 h Pp, to pneumoperitoneum for 180 min. The animals were divided in half. One half of the rats were left resting for 30 min after abdominal desufflation and the other for 8 h. After these two time periods, blood, liver, kidney, lung and small intestine were obtained for biochemical analysis and histopathological examination. In the 3 h Pp, the associated oxidative stress was increased. There was an overt increase in blood and tissue MDA and blood PAB values. The MPO values were significantly higher in the 3 h Pp group in serum, kidneys, and intestine during the early phase of reperfusion and in liver after 8 h of reperfusion. These changes occurred in the presence of light microscopic evidence of greater tissue damage for the 3 h Pp, which were consistent with the fluctuation of the MPO values. In our experimental model, we proved biochemically and histologically that time of maintenance of pneumoperitoneum is an additive factor that could cause increased oxidative stress in laparoscopic procedures.

Research paper thumbnail of Unusual findings in inguinal hernia surgery: report of 6 rare cases

Hippokratia, 2009

To present our experience with unexpected findings during hernia surgery, either unusual hernial ... more To present our experience with unexpected findings during hernia surgery, either unusual hernial contents or pathologic entities, like neoplastic masses, masquerading as a hernia. We studied retrospectively 856 patients with inguinal hernia who were admitted to our surgical department over a 9-year period. In addition, our study included patients complaining of inguinal protrusion, even without a definitive diagnosis of inguinal hernia upon admission. Five patients presented with unusual hernial contents. Three of them had a vermiform appendix in their sac. Acute appendicitis (Amyands hernia) was found in only one case. One patient had epiploic appendagitis related with a groin hernia. Moreover, an adult woman was diagnosed with ovarian and tubal inguinal hernia. Finally, we report a case of a massive extratesticular intrascrotal lipoma, initially misdiagnosed as a scrotal hernia. a hernia surgeon may encounter unexpected intraoperative findings. It is important to be prepared to de...

Research paper thumbnail of The Oxidative Effect of Prolonged CO2 Pneumoperitoneum A Comparative Study in Rats

Journal of Surgical Research, 2012

Research paper thumbnail of Sentinel Node Biopsy Using a Magnetic Tracer Versus Standard Technique: The SentiMAG Multicentre Trial

Annals of Surgical Oncology, 2014

Background. The SentiMAG Multicentre Trial evaluated a new magnetic technique for sentinel lymph ... more Background. The SentiMAG Multicentre Trial evaluated a new magnetic technique for sentinel lymph node biopsy (SLNB) against the standard (radioisotope and blue dye or radioisotope alone). The magnetic technique does not use radiation and provides both a color change (brown dye) and a handheld probe for node localization. The primary end point of this trial was defined as the proportion of sentinel nodes detected with each technique (identification rate). Methods. A total of 160 women with breast cancer scheduled for SLNB, who were clinically and radiologically node negative, were recruited from seven centers in the United Kingdom and The Netherlands. SLNB was undertaken after administration of both the magnetic and standard tracers (radioisotope with or without blue dye). Results. A total of 170 SLNB procedures were undertaken on 161 patients, and 1 patient was excluded, leaving 160 patients for further analysis. The identification rate was 95.0 % (152 of 160) with the standard technique and 94.4 % (151 of 160) with the magnetic technique (0.6 % difference; 95 % upper confidence limit 4.4 %; 6.9 % discordance). Of the 22 % (35 of 160) of patients with lymph node involvement, 16 % (25 of 160) had at least 1 macrometastasis, and 6 % (10 of 160) had at least a micrometastasis. Another 2.5 % (4 of 160) had isolated tumor cells. Of 404 lymph nodes removed, 297 (74 %) were true sentinel nodes. The lymph node retrieval rate was 2.5 nodes per patient overall, 1.9 nodes per patient with the standard technique, and 2.0 nodes per patient with the magnetic technique.

Research paper thumbnail of Sentinel Node Biopsy Using a Magnetic Tracer Versus Standard Technique: The SentiMAG Multicentre Trial

Annals of Surgical Oncology, 2014

Background. The SentiMAG Multicentre Trial evaluated a new magnetic technique for sentinel lymph ... more Background. The SentiMAG Multicentre Trial evaluated a new magnetic technique for sentinel lymph node biopsy (SLNB) against the standard (radioisotope and blue dye or radioisotope alone). The magnetic technique does not use radiation and provides both a color change (brown dye) and a handheld probe for node localization. The primary end point of this trial was defined as the proportion of sentinel nodes detected with each technique (identification rate). Methods. A total of 160 women with breast cancer scheduled for SLNB, who were clinically and radiologically node negative, were recruited from seven centers in the United Kingdom and The Netherlands. SLNB was undertaken after administration of both the magnetic and standard tracers (radioisotope with or without blue dye). Results. A total of 170 SLNB procedures were undertaken on 161 patients, and 1 patient was excluded, leaving 160 patients for further analysis. The identification rate was 95.0 % (152 of 160) with the standard technique and 94.4 % (151 of 160) with the magnetic technique (0.6 % difference; 95 % upper confidence limit 4.4 %; 6.9 % discordance). Of the 22 % (35 of 160) of patients with lymph node involvement, 16 % (25 of 160) had at least 1 macrometastasis, and 6 % (10 of 160) had at least a micrometastasis. Another 2.5 % (4 of 160) had isolated tumor cells. Of 404 lymph nodes removed, 297 (74 %) were true sentinel nodes. The lymph node retrieval rate was 2.5 nodes per patient overall, 1.9 nodes per patient with the standard technique, and 2.0 nodes per patient with the magnetic technique.

Research paper thumbnail of Preventing intraperitoneal adhesions with atorvastatin and sodium hyaluronate/carboxymethylcellulose: a comparative study in rats

The American Journal of Surgery, 2010

OBJECTIVES: The aim of this study was to compare the effectiveness of atorvastatin with the sodiu... more OBJECTIVES: The aim of this study was to compare the effectiveness of atorvastatin with the sodium hyaluronate/carboxymethylcellulose (HA/CMC, Seprafilm; Genzyme; Genzyme Biosurgery Corporation, Cambridge, MA) in preventing postoperative intraperitoneal adhesion formation in rats.

Research paper thumbnail of Management of Ingested Foreign Bodies. How Justifiable is a Waiting Policy?

Surgical Laparoscopy, Endoscopy & Percutaneous Techniques, 2008

Foreign body ingestion is a commonly seen accident in emergencies, usually in children (80%), eld... more Foreign body ingestion is a commonly seen accident in emergencies, usually in children (80%), elderly, mentally impaired, or alcoholic individuals, whereas it may occur intentionally in prisoners or psychiatric patients. According to the literature, 90% of ingested foreign bodies pass through the gastrointestinal tract without complications, 10% to 20% necessitate endoscopic removal, whereas only 1% of them will finally need surgical intervention. In clinical practice, we often face the dilemma of choosing the appropriate treatment modality. We present 13 cases treated in our department, emphasizing in a "waiting and close observation" policy. Among these cases, only 1 patient needed to be operated because of obstruction of ileocecal valve by a large coin. Indications for treatment where applicable are also being discussed.

Research paper thumbnail of Laparoscopic cholecystectomy in patients with previous upper or lower abdominal surgery

Research paper thumbnail of A Rare Case of Malignant Triton Tumor with Pluridirectional Differentiation

Southern Medical Journal, 2009

An enlarging soft tissue mass was resected from the leg of a young man with neurofibromatosis typ... more An enlarging soft tissue mass was resected from the leg of a young man with neurofibromatosis type 1. Rhabdomyosarcomatous elements admixed with islands of osteoid and chondroid matrix was seen on microscopy. Based on immunohistochemistry, a malignant triton tumor, an uncommon subtype of peripheral nerve sheath tumor with rhabdomyosarcomatous elements, was diagnosed. The important feature of this neoplasm was that it showed pluridirectional differentiation to osteosarcoma and chondrosarcoma. This pathologic finding is rare and seen in only a few cases of all malignant triton tumors.

Research paper thumbnail of The Oxidative Effect of Prolonged CO2 Pneumoperitoneum A Comparative Study in Rats

Journal of Surgical Research, 2012

The current study evaluated the effect of time in the severity of the oxidative stress due to pne... more The current study evaluated the effect of time in the severity of the oxidative stress due to pneumoperitoneum. Forty Wistar rats were allocated randomly into 2 groups. The 1 h pneumoperitoneum (Pp) group, which was subjected to 60 min of pneumoperitoneum, and the 3 h Pp, to pneumoperitoneum for 180 min. The animals were divided in half. One half of the rats were left resting for 30 min after abdominal desufflation and the other for 8 h. After these two time periods, blood, liver, kidney, lung and small intestine were obtained for biochemical analysis and histopathological examination. In the 3 h Pp, the associated oxidative stress was increased. There was an overt increase in blood and tissue MDA and blood PAB values. The MPO values were significantly higher in the 3 h Pp group in serum, kidneys, and intestine during the early phase of reperfusion and in liver after 8 h of reperfusion. These changes occurred in the presence of light microscopic evidence of greater tissue damage for the 3 h Pp, which were consistent with the fluctuation of the MPO values. In our experimental model, we proved biochemically and histologically that time of maintenance of pneumoperitoneum is an additive factor that could cause increased oxidative stress in laparoscopic procedures.

Research paper thumbnail of Unusual findings in inguinal hernia surgery: report of 6 rare cases

Hippokratia, 2009

To present our experience with unexpected findings during hernia surgery, either unusual hernial ... more To present our experience with unexpected findings during hernia surgery, either unusual hernial contents or pathologic entities, like neoplastic masses, masquerading as a hernia. We studied retrospectively 856 patients with inguinal hernia who were admitted to our surgical department over a 9-year period. In addition, our study included patients complaining of inguinal protrusion, even without a definitive diagnosis of inguinal hernia upon admission. Five patients presented with unusual hernial contents. Three of them had a vermiform appendix in their sac. Acute appendicitis (Amyands hernia) was found in only one case. One patient had epiploic appendagitis related with a groin hernia. Moreover, an adult woman was diagnosed with ovarian and tubal inguinal hernia. Finally, we report a case of a massive extratesticular intrascrotal lipoma, initially misdiagnosed as a scrotal hernia. a hernia surgeon may encounter unexpected intraoperative findings. It is important to be prepared to de...

Research paper thumbnail of The Oxidative Effect of Prolonged CO2 Pneumoperitoneum A Comparative Study in Rats

Journal of Surgical Research, 2012

Research paper thumbnail of Sentinel Node Biopsy Using a Magnetic Tracer Versus Standard Technique: The SentiMAG Multicentre Trial

Annals of Surgical Oncology, 2014

Background. The SentiMAG Multicentre Trial evaluated a new magnetic technique for sentinel lymph ... more Background. The SentiMAG Multicentre Trial evaluated a new magnetic technique for sentinel lymph node biopsy (SLNB) against the standard (radioisotope and blue dye or radioisotope alone). The magnetic technique does not use radiation and provides both a color change (brown dye) and a handheld probe for node localization. The primary end point of this trial was defined as the proportion of sentinel nodes detected with each technique (identification rate). Methods. A total of 160 women with breast cancer scheduled for SLNB, who were clinically and radiologically node negative, were recruited from seven centers in the United Kingdom and The Netherlands. SLNB was undertaken after administration of both the magnetic and standard tracers (radioisotope with or without blue dye). Results. A total of 170 SLNB procedures were undertaken on 161 patients, and 1 patient was excluded, leaving 160 patients for further analysis. The identification rate was 95.0 % (152 of 160) with the standard technique and 94.4 % (151 of 160) with the magnetic technique (0.6 % difference; 95 % upper confidence limit 4.4 %; 6.9 % discordance). Of the 22 % (35 of 160) of patients with lymph node involvement, 16 % (25 of 160) had at least 1 macrometastasis, and 6 % (10 of 160) had at least a micrometastasis. Another 2.5 % (4 of 160) had isolated tumor cells. Of 404 lymph nodes removed, 297 (74 %) were true sentinel nodes. The lymph node retrieval rate was 2.5 nodes per patient overall, 1.9 nodes per patient with the standard technique, and 2.0 nodes per patient with the magnetic technique.

Research paper thumbnail of Sentinel Node Biopsy Using a Magnetic Tracer Versus Standard Technique: The SentiMAG Multicentre Trial

Annals of Surgical Oncology, 2014

Background. The SentiMAG Multicentre Trial evaluated a new magnetic technique for sentinel lymph ... more Background. The SentiMAG Multicentre Trial evaluated a new magnetic technique for sentinel lymph node biopsy (SLNB) against the standard (radioisotope and blue dye or radioisotope alone). The magnetic technique does not use radiation and provides both a color change (brown dye) and a handheld probe for node localization. The primary end point of this trial was defined as the proportion of sentinel nodes detected with each technique (identification rate). Methods. A total of 160 women with breast cancer scheduled for SLNB, who were clinically and radiologically node negative, were recruited from seven centers in the United Kingdom and The Netherlands. SLNB was undertaken after administration of both the magnetic and standard tracers (radioisotope with or without blue dye). Results. A total of 170 SLNB procedures were undertaken on 161 patients, and 1 patient was excluded, leaving 160 patients for further analysis. The identification rate was 95.0 % (152 of 160) with the standard technique and 94.4 % (151 of 160) with the magnetic technique (0.6 % difference; 95 % upper confidence limit 4.4 %; 6.9 % discordance). Of the 22 % (35 of 160) of patients with lymph node involvement, 16 % (25 of 160) had at least 1 macrometastasis, and 6 % (10 of 160) had at least a micrometastasis. Another 2.5 % (4 of 160) had isolated tumor cells. Of 404 lymph nodes removed, 297 (74 %) were true sentinel nodes. The lymph node retrieval rate was 2.5 nodes per patient overall, 1.9 nodes per patient with the standard technique, and 2.0 nodes per patient with the magnetic technique.