The Importance of Lumbar Lordosis During Laparoscopic Trocar Entry.

STUDY OBJECTIVE: Investigating the effect of lumbar lordosis on the relationship between abdominal trocar entry points and major vascular structures. DESIGN: Retrospective cohort. SETTING: Tertiary referral center. PATIENTS: Distances between the skin and the aorta and inferior vena cava at the trocar entry points, both at the umbilicus and 3 cm and 5 cm superior to the umbilicus, were measured at entry angles of 90 and 45 degrees in 101 abdominal computer tomography images. INTERVENTIONS: The relationship of these values with lumbar lordosis was investigated concerning menopausal status, body mass index (BMI), and parity differences. To assess the isolated effect of lumbar lordosis, a simulated 30-degree increase in the lordosis angle was applied to the patients' computed tomography images. The impact of this increased lumbar lordosis angle on the distances between the skin and major vessels was then evaluated at both the umbilical and supraumbilical trocar entry sites. MEASUREMENTS AND MAIN RESULTS: In the tomographic images of all patients, the distances from the skin to vascular structures were measured at a 90-degree entry angle, resulting in measurements of 8.97 cm ± 2.81 at the umbilicus, 10.89 cm ± 3.02 at 3 cm above the umbilicus, and 11.36 cm ± 2.88 at 5 cm above the umbilicus. These distances exhibited significant differences between patients with BMI <30 and BMI ≥30, as well as between premenopausal and postmenopausal patients. However, at a 45-degree entry angle, vascular structures were observed in only a few patients during trocar projection, and no measurable values were determined. In the simulation, it was found that a 1-degree increase in lumbar lordosis angle resulted in a decrease of 0.272 mm ± 0.018 in the distance between the skin and vascular structures at the umbilicus, 0.425 mm ± 0.024 at 3 cm above the umbilicus, and 0.428 mm ± 0.024 at 5 cm above the umbilicus. CONCLUSION: An increase in the degree of lumbar lordosis reduces the distance between trocar entry points and major vascular structures. Along with other factors during Veress and trocar entry, lumbar lordosis should be carefully considered.

Natural Phenolic Acid, Product of the Honey Bee, for the Control of Oxidative Stress, Peritoneal Angiogenesis, and Tumor Growth in Mice.

Tumor-associated macrophages (TAM) are key regulators of the link between inflammation and cancer, and the interplay between TAM and tumor cells represents a promising target of future therapeutic approaches. We investigated the effect of gallic acid (GA) and caffeic acid (CA) as strong antioxidant and anti-inflammatory agents on tumor growth, angiogenesis, macrophage polarization, and oxidative stress on the angiogenic model caused by the intraperitoneal (ip) inoculation of Ehrlich ascites tumor (EAT) cells (2.5 × 106) in Swiss albino mouse. Treatment with GA or CA at a dose of 40 mg/kg and 80 mg/kg ip was started in exponential tumor growth phase on days 5, 7, 9, and 11. On day 13, the ascites volume and the total number and differential count of the cells present in the peritoneal cavity, the functional activity of macrophages, and the antioxidant and anti-angiogenic parameters were determined. The results show that phenolic acids inhibit the processes of angiogenesis and tumor growth, leading to the increased survival of EAT-bearing mice, through the protection of the tumoricidal efficacy of M1 macrophages and inhibition of proangiogenic factors, particularly VEGF, metalloproteinases -2 and -9, and cyclooxygenase-2 activity.

Scleroderma renal crisis with coexisting segmental arterial mediolysis presenting as intraperitoneal bleeding: a case report.

BACKGROUND: Segmental arterial mediolysis is a rare nonarteriosclerotic and noninflammatory vascular disease that may cause intraperitoneal bleeding. Scleroderma renal crisis is a rare complication of systemic sclerosis, leading to severe hypertension and renal dysfunction. To the best of our knowledge, this is the first reported case of a patient with concurrent systemic sclerosis with scleroderma renal crisis and pathologically confirmed segmental arterial mediolysis. CASE PRESENTATION: We report a case of a 68-year-old Chinese woman diagnosed with systemic sclerosis who was found to have coexisting segmental arterial mediolysis. She presented with back pain, and massive intraperitoneal bleeding was detected by computed tomography. She underwent laparotomy, and the bleeding was found to originate from the gastroepiploic artery. The pathological examination demonstrated gastroepiploic arterial dissection caused by segmental arterial mediolysis. After surgery, she developed severe hypertension with hyperreninemia and progressive renal dysfunction. Given the risk factors of corticosteroid administration and the presence of anti-ribonucleic acid polymerase III antibody, she was diagnosed with scleroderma renal crisis. The patient was proved to have a very rare case of coexisting scleroderma renal crisis and segmental arterial mediolysis. CONCLUSIONS: There is no known etiological connection between segmental arterial mediolysis and systemic sclerosis or scleroderma renal crisis, but it is possible that coexisting segmental arterial mediolysis and scleroderma renal crisis may have interacted to trigger the development of the other in our patient.

Freehand diffuse optical spectroscopy imaging for intraoperative identification of major venous and arterial vessels underlying peritoneal fat: an in vivo demonstration in a pig model.

Inadvertent injury to important anatomic structures is a significant risk in minimally invasive surgery (MIS) that potentially requires conversion to an open procedure, which results in increased morbidity and mortality. Surgeons operating minimal-invasively currently do not have an easy-to-use, real-time device to aid in intraoperative identification of important anatomic structures that underlie tissue planes. We demonstrate freehand diffuse optical spectroscopy (DOS) imaging for intraoperatively identifying major underlying veins and arteries. An applicator probe that can be affixed to and detached from an 8-mm laparoscopic instrument has been developed. The 10-mm DOS source-detector separation renders sampling of tissue heterogeneities a few millimeters deep. DOS spectra acquired consecutively during freehand movement of the applicator probe on the tissue surface are displayed as a temporal and spectral image to assist in spatially resolved identification of the underlying structures. Open surgery identifications of the vena cava and aorta underlying peritoneal fat of ∼4 mm in thickness using the applicator probe under room light were demonstrated repeatedly in multiple pigs in vivo.

Idiopathic spontaneous lesser sac haematoma: a perplexing case of abdominal apoplexy.

A 37-year-old woman presented with a 3-hour history of back pain, nausea and vomiting and an episode of syncope. A fluid collection in the lesser sac was detected on ultrasound and CT scan. Emergency laparoscopy and subsequent laparotomy were performed and a large blood clot was evacuated from the lesser sac. No identifiable source or predisposition to bleeding was found. She made a full recovery postoperatively. There are few reported cases of spontaneous intraperitoneal haemorrhage. In a third of cases, there is no identifiable source of bleeding. Unfortunately, patients present late with non-specific symptoms and a prompt diagnosis is difficult to make. The case reiterates the importance of awareness of lesser sac haematoma formation; an unusual clinical entity with a high morbidity and mortality rate. A high index of suspicion, radiological adjuncts and appropriate surgical intervention, especially in unstable patients, is essential for a good outcome.

Fatal acute necrohaemorrhagic pancreatitis with massive intraperitoneal and retroperitoneal bleeding: a rare cause of exsanguination.

An otherwise healthy 37-year-old man was admitted to hospital with uncontrollable vomiting and abdominal pain. Lithiasic acute pancreatitis was diagnosed on the basis of clinical symptoms along with raised serum amylase levels and compatible findings in ultrasonography and CT scan. Two Ranson criteria (lactate dehydrogenase over 350 U/L and aspartate aminotransferase over 250 U/L) were present at admission. The patient was transferred to an intensive care unit (ICU); intravenous crystalloids were prescribed and analgaesics were administered for pain relief. Unexpectedly, 10 h after ICU admission, he presented a cardiac arrest with a non-defibrillate rhythm and died after 40 min of advanced life support. An autopsy was performed and revealed acute necrohaemorrhagic pancreatitis with massive intraperitoneal and retroperitoneal haemorrhage. This case report summarises the epidemiology, pathophysiology and risk factors for fatal bleeding acute pancreatitis.

A novel patchwork model used in lecture and laboratory to teach the three-dimensional organization of mesenteries.

Anatomy teaching is seeing a decline in both lecture and laboratory hours across many medical schools in North America. New strategies are therefore needed to not only make anatomy teaching more clinically integrated, but also to implement new interactive teaching techniques to help students more efficiently grasp the complex organization of the human body. Among the difficult anatomical concepts that students struggle to understand, the anatomy of the peritoneal cavity with its complex projections of peritoneum could benefit strongly from new learning aids. In this report, an innovative teaching tool is presented to engage students during both lecture and laboratory, and help them build three-dimensional (3D) mental maps of peritoneal cavity. The model consists of a patchwork of mesenteries and gut made from colored cloth stitched together onto a T-shirt to denote the origin and outflow of each peritoneum projection. As the lecturer wears the life-size model, the students can appreciate the 3D organization of the peritoneal cavity on a living body. In addition, the T-shirt model can be used in parallel with dissection to ensure a strong reinforcement of the spatial understanding of the peritoneal cavity.

Smad7 gene transfer attenuates angiogenesis in peritoneal dialysis rats.

AIM: Transforming growth factor-ß (TGF-ß) has been shown to play a role in peritoneal angiogenesis associated with peritoneal dialysis (PD). The present study investigated whether blockade of TGF-ß signalling with Smad7 has a therapeutic effect on PD induced-peritoneal angiogenesis. METHODS: A rat model of peritoneal dialysis was induced by a daily intraperitoneal injection of 4.25% Dianeal and lipopolysaccharides. PD rats were transfected with a doxycycline regulated, Smad7-expressing plasmid using an ultrasound-microbubble-mediated system on day 0 and day 14 after initiation of PD and an empty vector was used as control. Peritoneal microvessel density (MVD) in peritoneal tissue was assessed by anti-CD31 immunohistochemistry after 4 weeks of PD and peritoneal angiogenic growth factors, including vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and platelet-derived growth factor (PDGF) was also examined by immunofluorescence, western blot and reverse transcription-polymerase chain reaction. RESULTS: In contrast to the normal control group, at 4 weeks after PD, PD rats displayed peritoneal lesions, peritoneal angiogenesis and increased mRNA and protein expression of VEGF, bFGF and PDGF. Smad7 gene transfer significantly attenuated the peritoneal MVD and inhibited the upregulation of VEGF, bFGF and PDGF. Moreover, inhibition of peritoneal angiogenesis by overexpression of Smad7 was associated with inhibition of phosphorylation of Smad3 and downregulation of TGF-ß expression. CONCLUSION: Smad7 gene transfer via an ultrasound-microbubble-mediated system is able to attenuate peritoneal angiogenesis in a rat model of PD. Those results suggest that blockade of the TGF-ß/Smad signalling pathway may represent a novel therapeutic approach to prevent PD-induced peritoneal angiogenesis.

Fetal topographical anatomy of the upper abdominal lymphatics: its specific features in comparison with other abdominopelvic regions.

Using semiserial sections from 19 human fetuses of 8-30 weeks gestation, we examined the topohistology of the upper abdominal lymphatics and compared it with that of the lower abdominal and pelvic lymphatics. The upper abdominal lymphatics were characterized by an intimate relationship with the peritoneal lining, a common mesentery for the celiac trunk and superior mesenteric artery (SMA). Lymphatic connections from the upper abdominal viscera to the paraaortic and paracaval areas followed two routes: (1) from the intestinal mesentery, along the peritoneum on the left aspect of the proximal SMA, via the chain of lymph follicles (LFs) lying along the retropancreatic fusion fascia, to drain into the LFs around the left renal vein; (2) from sites along the peritoneum on the posterior wall of the omental bursa, via the root of the hepatoduodenal ligament, to drain into LFs around the vena cava. The development of these two posterior drainage routes seemed to be promoted by the peritoneum or a peritoneal remnant (i.e., fusion fascia) attaching to the great vessels, and inhibited or impeded by the developing nerves and diaphragm. No paraaortic, paracaval, or pelvic LFs lay along the peritoneum. The pelvic LFs were usually located along the bundle of lymphatic vessels originating from the femoral canal.

Intraperitoneal drug therapy: an advantage.

The peritoneum is a cavity which has been successfully utilized by nephrologists to perform peritoneal dialysis (PD) in patients with renal failure. The physiologic characteristic of the peritoneal cavity not only helps remove toxic metabolites from the body, but also provides a useful portal of entry in the body for several pharmacological agents. Several medications such as antibiotics are given via the intraperitoneal (IP) route in PD patients to treat episodes of peritonitis. More recently the IP route has been used for chemotherapy in patients with intra-abdominal malignancies, i.e. gynecological and gastrointestinal cancers and has shown very promising results. In patients with peritoneal surface malignancies, perioperative IP chemotherapy has been used with good results. The rate and amount of drug transfer in the peritoneum are dependent on several factors. Factors such as peritoneal inflammation, surface area, peritoneal blood flow, time of contact, etc, influence the drug transfer. This review discusses the usefulness of IP drug therapy and the factors influencing it, as well as strategies to increase the efficacy, and conclude that IP route is an alternate route to the more conventional drug delivery routes, and can be successfully used when the target is within the peritoneal cavity or adjacent tissue.

Mechanisms of direct peritoneal resuscitation-mediated splanchnic hyperperfusion following hemorrhagic shock.

Conventional resuscitation (CR) from hemorrhagic shock causes a persistent and progressive splanchnic vasoconstriction and hypoperfusion despite hemodynamic restoration with intravenous fluid therapy. Adjunctive direct peritoneal resuscitation (DPR) with a clinical peritoneal dialysis solution instilled into the peritoneal cavity has been shown to restore splanchnic tissue perfusion, down-regulate the gut-derived exaggerated systemic inflammatory response, promote early fluid mobilization, and improve overall outcome. This study was conducted to define the molecular mechanisms of DPR-induced gut hyperperfusion after hemorrhagic shock. Male rats were bled to 50% baseline mean arterial pressure and resuscitated with the shed blood plus two volumes of saline (CR). In vivo videomicroscopy and Doppler velocimetry were used to assess terminal ileal microvascular diameters and blood flow. Direct peritoneal resuscitation animals received CR and topical application of a clinical glucose-based peritoneal dialysis solution (Delflex). Inhibitors, glibenclamide (K(+)ATP channels), N-monomethyl-L-arginine (L-NMMA) (nitric oxide synthase), 8-cyclopentyl-1,3-diprophylxanthine (DPCPX) (A1 adenosine receptor), tetrabutylammonium (K(+)Ca2+ channels), and mefenamic acid (cyclooxygenase) were topically applied (individually or in combination) with DPR according to protocol; BQ-123 (endothelin A receptor antagonist) and BQ-788 (endothelin B receptor antagonist) were used topically with CR to define the mechanism of post-CR vasoconstriction and hypoperfusion. Conventional resuscitation caused a persistent progressive intestinal vasoconstriction and hypoperfusion that can be abolished with endothelin antagonists. In contrast, adjunctive DPR caused an instantaneous sustained vasodilation and hyperperfusion. Glibenclamide or L-NMMA partially attenuated DPR-induced vasodilation, whereas the addition of DPCPX to the two inhibitors eliminated the dilation. Cyclooxygenase and K(+)Ca2+channels were not active in DPR-mediated microvascular effects. In conclusion, DPR improves splanchnic tissue perfusion by endothelium-dependent mechanisms mediated by activations of glibenclamide-sensitive K(+) channels (KATP), adenosine A1 receptor subtype activation, and nitric oxide release. Direct peritoneal resuscitation preserves endothelial dilatory functions, thereby overriding any endothelium-derived constrictor response triggered by hemorrhagic shock and CR.

Analysis of the inflammatory reaction induced by the catfish (Cathorops spixii) venoms.

Cathorops spixii is one of the most abundant venomous fish of the southeastern coast of the State of São Paulo, and consequently causes a great part of the accidents seen there. The accidents affect mainly fishermen, swimmers and tourists and are characterized by punctiform or wide wounds, erythema, edema, pain, sudoresis, indisposition, fever, nausea, vomiting and secondary infection. The objective of this work was to characterize the inflammatory response induced in mice by both venoms (mucus and sting) of the catfish C. spixii. Our results demonstrated that both venoms induced a great number of rolling and adherent leukocytes in the post-capillary venules of cremaster muscle of mice, and an increase in the vascular permeability in peritoneal cavity. Mucus induced the recruitment of neutrophils immediately after injection followed later by macrophage infiltration. In contrast, the cellular infiltration elicited by sting venom was rapidly resolved. The peritonitis reaction provoked by venoms was characterized by cytokine (IL-6), chemokines (MCP-1 and KC) or lipid mediator (LTB4) production in the peritoneal cavity. The macrophages from 7-day mucus venom-induced exudates upon in vitro mucus venom stimulation, expressed CD11c x MHC class II and release bioactive IL-12p70. On the other hand, sting venom-elicited peritoneal macrophages lost the ability to differentiate into dendritic cells, following re-stimulation in vitro with sting venom, they do not express CD11c, nor do they exhibit sufficient levels of MHC class II. In conclusion, both types of venoms (mucus or sting) promote inflammatory reaction with different profiles, and the inflammatory reaction induced by the first was characterized by antigen persistence in peritoneal cavity that allowed the activation of phagocytic cells with capacity of antigenic presentation.

[The influence of different microenvironments on melanoma invasiveness and microcirculation patterns].

OBJECTIVE: To investigate the influence of different microenvironments on tumor microcirculation patterns and invasive capability. METHODS: Melanoma B16 cells were injected into the peritoneal cavity and skeletal muscle of C57 mice synchronously. CK18 expression in melanoma was assessed to distinguish the malignant phenotype of tumors in the peritoneal cavity from that in the skeletal muscle. HIF-1alpha, MMP-2 and MMP-9 protein and mRNA expression were compared in the two microenvironments. Cells positive for each immunohistochemical stain and the vessels representative of each type of microcirculation pattern were evaluated in two microenvironments. RESULTS: CK18 and HIF-1alpha expression in melanoma were significantly higher in the skeletal muscle than in the peritoneal cavity (t = 8.142, t = 3.645, P < 0.05). Compared with the peritoneal cavity, melanoma cells in the skeletal muscle overexpressed MMP-2 and MMP-9 (t = 4.916, t = 7.782, P < 0.05). Real time-PCR results also showed that MMP-2 and MMP-9 mRNA levels in melanoma were higher in the skeletal muscle than in the peritoneal cavity (t = 36.814, t = 26.025, P < 0.05). Vasculogenic mimicry channels and endothelium-dependent vessels were the major microcirculation patterns in the skeletal muscle and in the peritoneal cavity respectively. CONCLUSIONS: Different microenvironments affect invasiveness and blood supply patterns of melanoma. Different microenvironment induced tumor cell secretion of more invasion-related proteins and affect invasiveness and blood supply patterns of melanoma.

5-FU uptake in peritoneal metastases after pretreatment with radioimmunotherapy or vasoconstriction: an autoradiographic study in the rat.

This study was conducted to test if tumour drug uptake could be increased in experimental colorectal cancer peritoneal metastases, by using pretreatment with peritoneal vasoconstriction or radioimmunotherapy. A total of 29 nude rats with peritoneal metastases were injected intraperitoneally (i.p.) with 14C-labelled 5-FU. The animals were randomly allocated to 5 groups. Six days prior to 5-FU, group I (control) received i.p. NaCl, group II was subjected to i.p. radioimmunotherapy (RIT) 131I-labelled anti-CEA monoclonal antibody (150 MBq) and group III received i.p. Norbormide 10 minutes before 5-FU. Two days prior to 5-FU group IV and V received i.p. NaCl (control) and RIT, respectively. 5-FU uptake was visualised with autoradiography and quantified by computer-based image analysis. Tumours in group III showed a higher uptake (mean+/-SD, 21.4+/-17) than in group I (11.8+/-10, p=0.04). This was also true when the analysis was restricted to larger tumours (> or = median 627 pixels) group III (23.2+/-19) vs. group I (11.8+/-7, p=0.002). Peritoneal tumours in group II were of smaller size (median area 308 pixels) than in group I (619 pixels), in group III (901 pixels), in group IV (769 pixels) and in group V (808 pixels). RIT decreased the tumour size whereas it did not affect 5-FU uptake. The uptake of 5-FU was potentiated by pretreating the animals with Norbormide. These results demonstrate that 5-FU uptake in experimental peritoneal metastases is increased when the peritoneal absorption of the drug is blocked using pretreatment with a vasoconstrictive agent. This principle may also be relevant when treating patients with colorectal cancer peritoneal metastases.

Effects of an angiotensin II receptor blocker, valsartan, on residual renal function in patients on CAPD.

BACKGROUND: Both residual renal function and blood pressure (BP) control contribute to patient survival in patients receiving continuous ambulatory peritoneal dialysis (CAPD). It is unknown whether antihypertensive drugs affect residual renal function in addition to BP reduction. METHODS: We examined the effects of an angiotensin II receptor blocker, valsartan, on residual renal function and total clearance (renal and peritoneal) in 34 Japanese CAPD patients from 3 months to 2 years after the start of dialysis therapy. Patients were randomly assigned to valsartan (n = 18; age, 63.5 +/- 3.7 years; 11 men, 7 women) or a control group (n = 16; age, 63.5 +/- 3.3 years; 10 men, 6 women). Conventional antihypertensive treatment was continued in all patients to achieve the target BP in both groups of 130/80 mm Hg or less, measured at home. RESULTS: BP reduction was similar in the valsartan and control groups. Valsartan significantly slowed the progressive decline in both residual renal function (3.2 +/- 0.3 to 4.3 +/- 0.7 mL/min/1.73 m2) and total clearance (42.1 +/- 3.2 to 48.3 +/- 4.8 L/wk/1.73 m2) by dialysis in CAPD patients compared with controls (5.9 +/- 0.5 to 2.8 +/- 0.4 mL/min/1.73 m2; 47.1 +/- 4.8 to 31.4 +/- 5.2 L/wk/1.73 m2). CONCLUSION: This study shows that in patients with hypertension starting CAPD therapy, valsartan slows the decline in residual renal function and contributes to maintenance of weekly creatinine clearance and Kt/V (fraction per dialysis), which are the major factors contributing to the mortality and morbidity of CAPD patients. This effect appears to be mostly a result of maintaining residual renal function.

In vivo engineering of blood vessels.

The inadequacy of conventional synthetic grafts has led to efforts to construct a superior vascular graft. In vivo tissue engineering is one approach to this problem that has been investigated for half a century and enables the construction of autogenous vascular prostheses. Three types of in vivo engineering are explored: remodelling of implanted scaffolds, fibrocollagenous tubes, and the artificial artery generated in the peritoneal cavity. Scaffolds designed to be remodelled may be synthetic or biological and have been remodelled in animal models to form vasoactive neoarteries with arterial morphology. The differences in vascular remodelling ability, particularly spontaneous endothelialisation, between animal models and humans may impair the effectiveness of this approach in the clinic. Fibrocollagenous tubes such as the Sparks Mandril have demonstrated poor performance in the clinic and are prone to aneurysm formation. The artificial artery generated in the peritoneal cavity is a novel addition to the ranks of in vivo engineered vascular prostheses and combines many of the best features of scaffolds designed to be remodelled and fibrocollagenous tubes. However, understanding and manipulating the vascular remodelling process will be the key to producing the ideal arterial prosthesis.