Is there anybody out there: what do senior surgeons expect of their youngsters?

Surgery is indeed one of the most fascinating medical professions. However, it is also a stressful field of work with a high workload, and often leaves little time for personal and family needs. Within the last decade, a noticeable decline occurred in the willingness of medical students to enter a surgical residency. In fact, Generation Y is highly interested in a medical career with a respectful working atmosphere and balanced work and private life, as published in several recent papers. Therefore, surgery must evolve with the times to retain its attractiveness as a career choice for medical students and to compete for the best talents from Generation Y. However, little is known about what senior surgeons really expect from young surgical residents. On the basis of a recent survey by the Professional Association of German Surgeons, this paper tries to give some insights in this very relevant topic and a perspective on how to increase the attractiveness of our fascinating specialty. In fact, in this survey, senior surgeons defined a very clear requirement profile for surgical residency applicants. While the colleagues defined accurate applicant documents, a previous internship, self-motivation, and impressions from the job interview as the most important factors for a successful application for a surgical residency, a standard period of study or a dissertation was deemed of lower importance.

Vascular anatomy of the small intestine-a comparative anatomic study on humans and pigs.

BACKGROUND: Porcine models are well established for studying intestinal anastomotic healing. In this study, we aimed to clarify the anatomic differences between human and porcine small intestines. Additionally, we investigated the influences of longitudinal and circular sutures on human small intestine perfusion. METHODS: Intestines were obtained from human cadavers (n = 8; small intestine, n = 51) and from pigs (n = 10; small intestine, n = 60). Vascularization was visualized with mennige gelatin perfusion and high-resolution mammography. Endothelial cell density was analyzed with immunohistochemistry and factor VIII antibodies. We also investigated the influence of suture techniques (circular anastomoses, n = 19; longitudinal sutures, n = 15) on vascular perfusion. RESULTS: Only human samples showed branching of mesenteric vessels. Compared to the pig, human vessels showed closer connections at the entrance to the bowel wall (p = 0.045) and higher numbers of intramural anastomoses (p < 0.001). Porcine main vessels formed in multifilament-like vessel bundles and displayed few intramural vessel anastomoses. Circular anastomoses induced a circular perfusion defect at the bowel wall; longitudinal anastomoses induced significantly smaller perfusion defects (p < 0.001). Both species showed higher vascular density in the jejunum than in the ileum (p < 0.001). Human samples showed similar vascular density within the jejunum (p = 0.583) and higher density in the ileum (p < 0.001) compared to pig samples. CONCLUSION: The results showed significant differences between human and porcine intestines. The porcine model remains the standard for studies on anastomotic healing because it is currently the only viable model for studying anastomosis and wound healing. Nevertheless, scientific interpretations must consider the anatomic differences between humans and porcine intestines.

Comparison of intestinal microcirculation and wound healing in a rat model.

PURPOSE: If a colonic or small bowel lesion is not accessible for endoscopic mucosal resection, enterotomy is a possible although rarely performed surgical technique. It has never been compared to circular anastomosis regarding leakage rate, bowel wall perfusion, and wound healing. Thus, the aim of this basic experimental scientific study was to investigate perianastomotic microcirculation and wound healing. METHODS: Forty rats were divided into four groups (1 jejunal anastomosis, 2 jejunal enterotomy, 3 colonic anastomosis, and 4 colonic enterotomy). Following anastomosis and enterotomy, the intestinal perfusion was measured using laser fluorescence angiography (IC-View). On postoperative day 7, the surface of the mucosal villi, expression of matrix metalloproteinases (MMP) 2, 8, 9, and 13, and the number of proliferating cells (Ki67) as well as the collagen types I/III ratio were analyzed. RESULTS: The perianastomotic microperfusion was significantly reduced in all groups compared to the reference region. The perianastomotic perfusion index was significantly reduced in group 1 compared with group 2, whereas the perfusion index in group 3 was slightly but not significantly reduced in comparison to group 4. Ki67 was elevated in both circular anastomosis groups. Surface of the mucosal villi, MMP expression, and collagen type I/III ratio revealed no significant differences. CONCLUSIONS: Our study affirms the theoretical consideration of a better microperfusion of the bowel wall following an antimesenterial enterotomy and demonstrates that enterotomy is not inferior compared to circular anastomosis. Even though enterotomy is a rarely used surgical technique, it should be regarded as a possible alternative in particular situations.

Balancing zinc deficiency leads to an improved healing of colon anastomosis in rats.

BACKGROUND: In colorectal surgery, anastomotic leakage is a relevant complication. The aim of this study was to investigate whether intraperitoneally (i.p.) administered zinc improves the healing of colon anastomosis in rats. MATERIALS AND METHODS: Male Wistar rats (66) received zinc-deficient diet for 21 days. To determine the effective dose of zinc which is necessary to compensate this deficiency, preliminary analysis in 30 rats were performed. In these rats, analysis by atom-absorption spectrophotometry revealed a dose of 1.0 mg zinc aspartate/kg body weight to be the compensatory dosage. In the remaining zinc-deficient rats (n= 36), a transverse colonic anastomosis was performed. Eighteen rats received either a zinc supplementation i.p. or 0.9% NaCl i.p. (n = 18; control group). On postoperative days 3, 5, and 14, the surface of the mucosal villi, expression of MMP 2, MMP 8, MMP 13, TIMP 1, as well as the collagen types I/III ratio were analyzed. RESULTS: Protein expression of MMP 2 and MMP 8 was significantly higher in the anastomosis of the zinc group on day 3 and on day 5. The collagen types I/III ratio was significantly increased in the zinc group on days 5 and 14. CONCLUSION: Balancing zinc deficiency benefits wound healing of colonic anastomosis qualitatively due to an increased collagen type I/III ratio. Surprisingly, these zinc supplements, however, increased the expression of MMP 2 and MMP 8 that are supposed to impair wound healing in case of an over-expression. Thus, further investigations are needed to elucidate the influence of zinc supplementation on regulation of MMPs.

Zinc deficiency impairs wound healing of colon anastomosis in rats.

BACKGROUND: Anastomotic leakage is a relevant surgical complication. The aim of the study was to investigate the influence of a controlled preoperative zinc deficiency on the extracellular matrix composition of colon anastomosis. MATERIALS AND METHODS: Forty male Wistar rats were randomized to either a zinc deficiency group (n = 20) or a control group (n = 20). In each animal, a transverse colonic end-to-end anastomosis was performed. On postoperative day 7, the surface of the mucosal villi, expression of matrix metalloproteinases (MMP) 2, 8, 9, and 13, and both the number of proliferating cells (Ki67) and apoptotic cells, as well as the collagen types I/III ratio were analyzed. Within the anastomotic area the mesenterial region and the antimesenterial region were analyzed separately. RESULTS: In each group, one anastomotic leakage was detected. Expression of both MMP 2, 9, and 13 was significantly higher, and expression of Ki67 was significantly reduced in the zinc deficient group both mesenterial and antimesenterial. The collagen types I/III ratio was reduced in the zinc deficiency group by trend, without statistical significance neither mesenterial nor antimesenterial. Likewise, zinc deficiency affected neither the expression of MMP 8 nor the rate of apoptotic cells, respectively. Analyses of the surface of the mucosal villi revealed no significant differences comparing the groups with neither mesenterial nor antimesenterial. CONCLUSIONS: Our study constitutes the known negative effect of zinc deficiency on wound healing. Zinc deficiency significantly increased the activity of MMPs (2, 9, and 13), caused a reduced collagen type I/III ratio, and delayed cell proliferation and quality of intestinal wound healing.

Intraperitoneally applied gentamicin increases collagen content and mechanical stability of colon anastomosis in rats.

BACKGROUND: Anastomotic leakage remains a serious complication in colorectal surgery, and is being caused by a multitude of factors. Recent reports reveal changes of the extracellular matrix as risk factors as well as gentamicin as a potential agent to influence wound healing. This experimental study was initiated to investigate the influence of intraperitoneally applied gentamicin on colonic anastomotic wound healing and in particular on mechanical stability, overall collagen content and collagen type I/III ratio. MATERIALS AND METHODS: Sixty Sprague Dawley rats were randomized to one of two groups. In each animal, a standard transverse colonic end-to-end anastomosis was performed. Immediately postoperative, either 5 ml gentamicin (1 ml/kg bodyweight) or NaCl 0.9% was applied intraperitoneally. On postoperative days 3, 5, and 14, ten of the animals in each group were sacrificed. Measurements of the anastomosis bursting pressure were performed on postoperative days 3 and 5. At each explantation time, the collagen per protein ratio, the collagen types I/III ratio, and both the expression of MMP-2, -9, and Ki67 were analyzed. RESULTS: None of the animals died. None of the rats exhibited clinical evidence of anastomotic leakage. The bursting strength in the gentamicin group was significantly elevated on postoperative day 5. Both the overall collagen content and the collagen type I/III ratio in the gentamicin group were significantly increased 3, 5, and 14 days postoperatively compared to the control group. The expression of MMP-9 was significantly elevated in the gentamicin group both 3 and 5 days postoperatively. In contrast, there were no significant differences in the expression of MMP-9 14 days postoperatively. All investigated samples demonstrated positive staining for MMP-2 and Ki67 without statistically significant differences at any term, respectively. CONCLUSIONS: The present data confirm that intraperitoneally applied gentamicin is able to enhance healing and stability of colonic anastomosis due to an increase of both the overall collagen content and collagen type I/III ratio.

Incisional hernia: challenge of re-operations after mesh repair.

BACKGROUND AND AIMS: The widespread use of meshes for the repair of incisional hernia is currently followed by an increasing number of re-operations. The incidence of incisional hernia recurrence after mesh repair varies between 3 and 32%. The problem of mesh failure and options for another surgical intervention seem rather unattended. METHODS: We present our experience of 77 re-operations after previous mesh repair that were performed between 1995 and 2004 out of a total of 1,070 operations for incisional hernia. The retrospective analysis focused on recurrence in relation to location, material of the previous mesh repair and the surgical procedure to resolve the problem. RESULTS: The locations of the preceding meshes were epifascial as onlays (n=23), retromuscular as sublays (n=46), within the defect as inlays (n=6) or intraperitoneally (n=2). The direction of the incision was vertical medial (n=41) or horizontal crossing the linea semilunaris (n=36). Recurrences after median incisional hernia mesh repair mainly occurred at the cranial border of the mesh subxiphoidal. Except for two patients, all recurrences manifested at the margin of the enclosed mesh. CONCLUSIONS: Re-operation after previous mesh repair is a surgical challenge. The type of revision procedure has to consider the position and material of the previous mesh. In our clinic recurrences, heavyweight polypropylene meshes were mostly treated with mesh exchange and lightweight polypropylene meshes could be treated by extension with a second mesh. In contrast to suture techniques, deficient mesh repairs are more evidently related to technical problems.

Missing effects of zinc in a porcine model of recurrent endotoxemia.

BACKGROUND: Chronic human sepsis often is characterised by the compensatory anti-inflammatory response syndrome (CARS). During CARS, anti-inflammatory cytokines depress the inflammatory response leading to secondary and opportunistic infections. Proved in vitro as well as in vivo, zinc's pro-inflammatory effect might overcome this depression. METHODS: We used the model of porcine LPS-induced endotoxemia established by Klosterhalfen et al. 10 pigs were divided into two groups (n = 5). Endotoxemia was induced by recurrent intravenous LPS-application (1.0 microg/kg E. coli WO 111:B4) at hours 0, 5, and 12. At hour 10, each group received an intravenous treatment (group I = saline, group II = 5.0 mg/kg elementary zinc). Monitoring included hemodynamics, blood gas analysis, and the thermal dilution technique for the measurement of extravascular lung water and intrapulmonary shunt. Plasma concentrations of IL-6 and TNF-alpha were measured by ELISA. Morphology included weight of the lungs, width of the alveolar septae, and rate of paracentral liver necrosis. RESULTS: Zinc's application only trended to partly improve the pulmonary function. Compared to saline, significant differences were very rare. IL-6 and TNF-alpha were predominately measured higher in the zinc group. Again, significance was only reached sporadically. Hemodynamics and morphology revealed no significant differences at all. CONCLUSION: The application of zinc in this model of recurrent endotoxemia is feasible and without harmful effects. However, a protection or restoration of clinical relevance is not evident in our setting. The pulmonary function just trends to improve, cytokine liberation is only partly activated, hemodynamics and morphology were not influenced. Further pre-clinical studies have to define zinc's role as a therapeutic tool during CARS.

Incisional hernia: open techniques.

Even with the routine use of mesh, repairing an incisional hernia is a challenge. Increasing evidence of impaired wound healing in these patients supports routine use of an open prefascial, retromuscular mesh repair. Basic pathophysiologic principles dictate that for a successful long-term outcome and prevention of recurrence a wide overlap underneath healthy tissue is required. The extent of this overlap should be 5 cm in all directions: surrounding the wound closure, subxiphoidal underneath the ribs, below the arcuate line, and retropubic.