The effects of the use of hyoscine-N-butylbromide during laparoscopic sleeve gastrectomy.

Objectives: Hyoscine-N-butylbromide is used by some surgeons during laparoscopic sleeve gastrectomy (LSG) to loosen gastric smooth muscles and to provide a more effective LSG. However, evidence-based data on the effects of hyoscine-N-butylbromide in laparoscopic sleeve gastrectomy are limited and its effect on sleeve gastrectomy surgery and weight loss is unknown. The aim of this study was to analyze the effect of intraoperatively administered hyoscine-N-butylbromide on stomach resection volume, weight loss and complications seen in patients undergoing LSG. Material and Methods: Patients who underwent laparoscopic sleeve gastrectomy due to morbid obesity were included in the study. Intraoperative hyoscine-N-butylbromide was administered to 52 patients (Group 1), not applied to the other 52 patients (Group 2). Age, sex, height, weight and body mass index (BMI) data of the patients were obtained retrospectively. The weight, BMI, percentage of total weight loss (TWL%) and percentage of excess weight loss (EWL%) of the patients were evaluated at postoperative third, sixth and 12th months. Results: Resected gastric volume (p= 0.111), length of stapler line (p= 0.944), operation time (p= 0.383), hospitalization time (p= 0.494) and postoperative complications (p> 0.05) did not differ between Groups 1 and 2. However, frequency of intraoperative tachycardia (p <0.001) and hypotension (p= 0.006) in Group 1 was significantly higher than in Group 2. TWL% and EWL% values were similar between the two groups at all-time points. Stapler line leakage was not observed in any patient during the postoperative period. Conclusion: Intraoperative hyoscine-N-butylbromide use is not effective on weight loss postoperatively in patients undergoing LSG. Although hypotension and tachycardia occured in some of patients, none of the patients had complaints in the early or long-term postoperative period. The use of hyoscine-N-butylbromide during LSG is safe but does not have any effect on weight loss.

Starting Antrectomy in Less than 2 cm from Pylorus at Laparoscopic Sleeve Gastrectomy.

OBJECTIVE: To evaluate the effect of antrectomy in which resection was started from 2 cm or closer to the pylorus on % excess weight loss (EWL), nausea, vomiting, and complication rates. STUDY DESIGN: Comparative study. PLACE AND DURATION OF STUDY: Antalya Training and Research Hospital, from April 2018 to December 2018. METHODOLOGY: Patients in whom laparoscopic sleeve gastrectomy (LSG)were done starting at a level of 2 cm or closer to pylorus were included in the study. Patients were divided into one of the two groups based on the distance between the pylorus and the resection margin: group 1 having resection ≤10 mm and group 2 at 11-20 mm. Above mentioned parameters were compared in both groups. RESULTS: Ninety-two patients were included. Postoperative nausea and vomiting rates were similar in both groups. At the end of the first year, % EWL was 82.9% and 73.5% in groups 1 and 2 (p=0.003). CONCLUSION: Starting antrectomy at a distance of 2 cm or less from the pylorus is safe and effective. Starting antrectomy at a distance of 1 cm or less from the pylorus in LSG provides effective weight loss without increasing complications. KEY WORDS: Bariatric surgery, Antrectomy, Laparoscopic sleeve gastrectomy, Complications.

Practices concerning sleeve gastrectomy in Turkey: A survey of surgeons.

BACKGROUND: Laparoscopic sleeve gastrectomy (LSG) is the most common bariatric surgical procedure. LSG is a restrictive procedure and in this operation stomach volume is greatly reduced. When the details of the procedure are examined, it is seen that there are many different methods surgery. AIM: To analyze approaches of surgeons performing LSG. METHODS: A questionnaire consist of 44 questions was sent by e-mail to the surgeons performing bariatric surgery. Approaches of surgery about preoperative period, surgical techniques and postoperative period was questioned. RESULTS: Different approaches about antibiotic prophylaxis, stapler line reinforcement utilization, application of intraoperative and postoperative leakage test, approach to the crus and hiatal hernia repair were detected. It was observed that a few partipicipants applied contrary to the guidelines of antibiotic prophlaxis and thromboembolism prophylaxis. Approaches about other subjects were generally similar. CONCLUSION: In this study, approaches about LSG that most common bariatric surgical procedure in our country was learned. According to these results, knowing the approaches in our country will be beneficial in terms of determining the training programs in bariatric surgery, improving surgical results and reducing the complications.

Is Intraoperative Leak Test Required in Laparoscopic Sleeve Gastrectomy?

OBJECTIVE: To investigate the efficacy of intraoperative leak test (IOLT) by methylene blue to identify the presence of leak during standardised sleeve gastrectomy (SG) procedure. STUDY DESIGN: Cross-sectional comparative study. PLACE AND DURATION OF STUDY: Department of General Surgery, Antalya Training and Research Hospital, Antalya, Turkery, between January 2017 and December 2018. METHODOLOGY: A total of 226 consecutive sleeve gastrectomised patients, on whom IOLT was not performed, were included in the study, and were named as group 1. In order to compare with these patients, 226 consecutive sleeve gastrectomised patients, on whom IOLT was performed, were named as group 2. The groups were compared for postoperative leak, other complications, and mortality. RESULTS: In group 1, leakage was detected in two patients. Although IOLT was negative in all patients of group 2, leakage was detected in two patients. The leakage rate (1.6%) was similar in both groups. In IOLT group, sensitivity and positive predictive value of IOLT was 0%; and negative predictive value was 99.1%. CONCLUSION: The routine use of an IOLT did not reduce the incidence of postoperative leak. IOLT should not be routinely performed, rather it would be appropriate for selected patients. Key Words: Laparoscopic sleeve gastrectomy, Intraoperative leak test, Stapler line leak.

Endoscopic parathyroidectomy via unilateral axillobreast approach.

Endoscopic parathyroid and thyroid surgery is becoming increasingly common. In this study, we present the results of patients who underwent Endo- scopic parathyroid via unilateral axillo-breast approach (EP via UABA). Three patients underwent EP via UABA. Patients were discharged on the next day after surgery, while at one month follow up all of them reported no further symptoms. Operation performed via two axiller and one areolar trochar. As different from open surgery, the strap muscles don't pulled laterally and not entered into the thyroid lobe from the midline. In this technique, the strap muscles are separated from the middle part of the strap muscles and the thyroid gland is reached from the middle of the strap muscles. In this way, N. laryngeal recurrence and parathyroid gland that usually located in the posterior aspect of the thyroid gland can be revealed clearly by reducing the risk of complications. EP via UABA can be performed safe effective procedure via good cosmetic results.

The potential effects of Ankaferd blood stopper and fibrin sealent on sleeve gastrectomy staple-line healing: An experimental study.

Staple-line bleeding and leakage is a life-threatening complication in obese patients following laparoscopic sleeve gastrectomy. The aim of this study was to examine the potential effects of Ankaferd blood stopper (ABS) and Fibrin Sealant (FS; Tisseel®) on sleeve gastrectomy staple-line healing in an experimental animal model. A total of 30 Wistar albino female rats were divided into three groups and were subjected to sleeve gastrectomy with linear stapling. Group A (control group) had nothing administered, Group B was administered FS on the staple-line, and Group C was administered ABS on the staple-line following sleeve gastrectomy. After sacrifice on postoperative day 5, anastomotic burst pressure, tissue hydroxyproline levels and histopathological parameters were measured. The results revealed that group C had the highest mean bursting pressure level. However, the values of this parameter were not found to differ significantly between the groups (P>0.05). Group B and C had a similar hydroxyproline levels but increased compared with group A (P<0.001). Histopathological parameters were similar between the groups, except macrophage scores in group C. In the present experimental study, ABS was demonstrated to improve gastric-sleeved staple-line healing compared with FS. ABS may be used as a novel reinforcement agent in bariatric surgery.

Effects of different intraabdominal pressure levels on oxidative stress markers in laparoscopic cholecystectomy.

OBJECTIVE: To evaluate the effect of laparoscopic cholecystectomy performed under different intraabdominal pressure on oxidative stress markers. MATERIAL AND METHODS: This prospective, randomized, controlled study examined 90 consecutive healthy patients who underwent elective laparoscopic cholecystectomy with the diagnosis of symptomatic cholelithiasis. The patients were divided into three groups, 30 patients in each. Group 1 included patients who underwent laparoscopic cholecystectomy at a CO2 pneumoperitoneum pressure of 7 mmHg, Group 2 patients who underwent laparoscopic cholecystectomy at a CO2 pneumoperitoneum pressure of 10 mmHg, and Group 3 patients who underwent laparoscopic cholecystectomy at a CO2 pneumoperitoneum pressure of 13 mmHg. Blood samples were collected preoperatively, perioperatively, and postoperatively for measurement of the serum levels of ischemia modified albumin and an analysis of total antioxidant status and total oxidant status. Intra-group comparisons were made. RESULTS: Group 1 experienced a significant increase in the postoperative ischemia modified albumin values compared to preoperative ischemia modified albumin values (p=0.013). Group 2 experienced a significant decrease in the perioperative total antioxidant status values compared to preoperative and postoperative total antioxidant status values (p=0.009). Group 3 experienced a significant increase in the perioperative total oxidant status and oxidative stress index values compared to preoperative values (p<0.001). Group 3 experienced a significant increase in the perioperative and postoperative ischemia modified albumin values compared to preoperative values (p<0.001). CONCLUSION: Increased levels of oxidative stress markers were detected in patients who underwent laparoscopic cholecystectomy at a high intraabdominal pressure level.

Analysis of the publishing rate and the number of citations of general surgery dissertations.

OBJECTIVE: A dissertation is a scientific document. However, if it is not published in a scientific journal, it will gain access to only a limited audience and thus will be unable to achieve its objective. Nevertheless, the rate of publishing in journals is not high among dissertations. In this study, we aimed to investigate the publishing rates of general surgery dissertations in journals and the total number of citations. MATERIAL AND METHODS: All medical dissertations that have been prepared at general surgery departments of university hospitals and presented between the years 2006 and 2008 were analyzed. The authors checked whether the dissertations were published in a journal or not, by searching the dissertation in 4 different resources with the name of their authors. RESULTS: Two hundred and thirty-two dissertations were included. Half of those dissertations were experimental animal studies. Seventy dissertations were published in various journals. Fifty one (22%) of these were published in Science Citation Index Expanded journals, while 19 (8.1%) of them were published in Turkish non-Science Citation Index Expanded journals. There was no significant difference in terms of publishing rates between study types. The number of annual citations per article was 1.1. The writer of the dissertation was the first author in 35 (68,6%) articles. CONCLUSION: The publishing rates of dissertations in general surgery is low, with only 22% being published in Science Citation Index Expanded journals. The citation rate was also detected to be low in our study. Consequently, a dissertation should be considered as a scientific research study and planned as such, not as obligatory assignments. The publishing rates of dissertations should be increased, and authors should be led and encouraged to publish their dissertations.

Why scientists perform animal experiments, scientific or personal aim?

OBJECTIVE: Although all animal studies are conducted in line with a specific purpose, we think that not all animal studies are performed for a scientific purpose but for personal curiosity or to fulfill a requirement. The aim of the present study is to reveal the purposes of experimental studies conducted on animals. MATHERIAL AND METHODS: We searched for experimental studies performed on rats in general surgery clinics via PubMed, and obtained the e-mail addresses of the corresponding authors for each study. Afterwards, we sent a 7-item questionnaire to the authors and awaited their responses. RESULTS: Seventy-three (22.2%) of 329 authors responded to the questionnaire. Within these studies, 31 (42.5%) were conducted as part of a dissertation, while the remaining 19 (26.0%) were conducted to meet the academic promotion criteria. Only 23 (31.5%) were conducted for scientific purposes. The cost of 41% of those studies was higher than 2500 $. CONCLUSION: As shown in this study, the main objective of carrying out animal studies in Turkey is usually to prepare a dissertation or to be entitled to academic promotion. Animal experiments must be planned and performed as scientific studies to support related clinical studies. Additionally, animal studies must have well-defined objectives and be carried out in line with scientific purposes that may lead to useful developments in medicine, rather than personal interests.

Methods for closure of appendix stump during laparoscopic appendectomy procedure.

The most frequent abdominal pathology requiring emergent surgery is acute appendicitis. Laparoscopic appendectomy has been performed for the treatment of acute appendicitis since 1983. Closure of the appendix stump is vital to prevent severe postoperative complications. Different methods are described for closure such as stapler, endoloop, titanium clips, non-absorbable polymer clips (hem-o-lok clip), handmade loops, transsection by Ligasure or with bipolar cautery. The ideal method should be safe, applicable and cheap. The most appropriate method remains to be controversial. All methods are reported as safe, but some have higher costs, and some prolong the operation. In this article, we reviewed clinical and experimental studies on different methods of stump closure, and we tried to compare the benefit of these methods over others.

The protective effect of intraperitoneal medical ozone preconditioning and treatment on hepatotoxicity induced by methotrexate.

The aim of this study is to determine the effects of medical ozone preconditioning and treatment on the methotrexate acute induced hepatotoxicity in rats that has not reports elsewhere. Eighteen rats were randomly assigned into three equal groups; control, Mtx and Mtx with ozone. Hepatotoxicity was performed with a single dose of 20 mg/kg Mtx to group 2 and group 3 at the fifteenth day. The medical ozone preconditioning was administered intraperitonealy in group 3 for fifteen days and more five days after inducing Mtx. The other rats of the group 1 and 2 received saline injection. At the twentyfirst day the blood and the liver tissue samples were obtained to measure the levels of liver enzymes ALT and AST, proinflamatory cytokines TNF-α, IL-1ß, malondialdehyde, glutathione and myeloperoxidase. And the histolopatological examination was evaluated for injury score. In our study Mtx administration caused a significant increase on the liver enzymes ALT and AST, the tissue MDA and MPO activity and significant decrease in the tissue GSH. Moreover the both pro-inflammatory cytokines were significantly increased in the Mtx group. Medical ozone preconditioning and treatment reversed all these biochemical parameters and histopathological changes of the hepatotoxicity induced by Mtx. We conclude that medical ozone ameliorates Mtx induced hepatotoxicity in rats.

Does intraperitoneal medical ozone preconditioning and treatment ameliorate the methotrexate induced nephrotoxicity in rats?

Methotrexate is a chemotherapeutic agent used for many cancer treatments. It leads to toxicity with its oxidative injury. The purpose of our study is investigating the medical ozone preconditioning and treatment has any effect on the methotrexate-induced kidneys by activating antioxidant enzymes in rats. Eighteen rats were divided into three equal groups; control, Mtx without and with medical ozone. Nephrotoxicity was performed with a single dose of 20 mg/kg Mtx intraperitoneally at the fifteenth day of experiment on groups 2 and 3. Medical ozone preconditioning was performed at a dose of 25 mcg/ml (5 ml) intraperitoneally everyday in the group 3 and treated with medical ozone for five more days while group 2 was received only 5 ml of saline everyday for twenty days. All rats were sacrificed at the end of third week and the blood and kidney tissue samples were obtained to measure the levels of TNF-α, IL-1ß, malondialdehyde, glutathione and myeloperoxidase. Kidney injury score was evaluated histolopatologically. Medical ozone preconditioning and treatment ameliorated the biochemical parameters and kidney injury induced by Mtx. There was significant increase in tissue MDA, MPO activity, TNF-α and IL-1ß (P<0.05) and significant decrease in tissue GSH and histopathology (P<0.05) after Mtx administration. The preconditioning and treatment with medical ozone ameliorated the nephrotoxicity induced by Mtx in rats by activating antioxidant enzymes and prevented renal tissue.

What are the Endoscopic and Pathological Characteristics of Colorectal Polyps?

BACKGROUND: Colon polyps need to be excised upon detection during colonoscopy due to the risk of malignancy irrespective of their size. In our study, we retrospectively evaluated the clinicopathological characteristics of polyps detected during colonoscopy. MATERIALS AND METHODS: We assessed 379 patients with polyps detected during colonoscopy between January 2010 and May 2012. The demographics, complaints, colonoscopy findings (shape, place and size of the polyp) and histopathological findings were recorded. We carried out statistical analysis using PASW 18.0 for Windows. RESULTS: There were 227 males (59.9%) and 152 females (40.1%) in the trial. The mean age was 53.8 years (32-90). The most common complaint was rectal bleeding (36.1%), followed by abdominal pain (35.4%). Polyps were detected most commonly in the rectosigmoid region (43.8%), followed by the descending colon (17.4%). Some 239 patients had a single polyp (63.1%) while 140 were found to have multiple polyps (36.9%). While tubular adenoma was the most common pathological type, occurring in 181 patients (47.8%), tubulovillous adenoma (14.2%) and hyperplastic polyp (12.7%) followed, occurring in 54 and 48 patients respectively. While 313 patients (82.6%) did not feature dysplasia, 37 patients (9.7%) exhibited low- grade dysplasia, 28 (7.7%) had high-grade dysplasia and 4 had cancer (1.1%). The rates of villous components and dysplasia were detected to be high among pedunculated polyps and polyps larger than 1 cm (p<0.001). CONCLUSIONS: Due to the fact that large-diameter polyps with malignant potential are commonly located in the left colon and have a high prevalence among the middle-aged individuals, it would be appropriate to screen this population at regular intervals via rectosigmoidoscopy.

Most cited articles in general surgery from Turkey.

OBJECTIVE: The citation number of an article gives us information about its quality and contribution to science. In this article, we aimed to find the most frequently cited article in general surgery from Turkey, and evaluate how these articles in general surgery contributed to the world literature. MATERIAL AND METHODS: We used the science citation index expanded database to find the most frequently cited articles in general surgery from Turkey. RESULTS: Among the 52 articles found, the most common subjects were as follows: hydatid cyst (21.1%), pilonidal disease (15.4%), laparoscopic operations (15.4%), breast diseases (11.5%), and inguinal hernia (7.7%). Two articles were cited in more than 100 articles. Furthermore, 48.8% of the articles were published from three major cities. Most articles were published between 2000 and 2004, and 65.4% of articles were case series. CONCLUSION: Most of the cited articles were about hydatid cyst and pilonidal disease, which are more common in the Turkish population compared with other countries. Evaluation of most cited articles is important to identify the fields in which Turkey contributes to the world literature.

Platelet function parameters in management of hepatic hydatid disease: a case-controlled study.

AIM: To evaluate platelet function in patients with a history of surgical treatment for hepatic hydatid disease (HD). METHODS: This retrospective case-controlled study was performed in a state hospital in Turkey from January 2009 to November 2013. The patients were divided into two groups: those evaluated in the preoperative period (Group 1) and those evaluated in the postoperative period (Group 2). The patient groups were compared with a control group (Group 3). All three groups were evaluated using laboratory records from day 1 of the preoperative period and day 30 of the postoperative period. The haematocrit level (HTC), platelet count (PLT), mean platelet volume (MPV), platelet distribution width (PDW), and percentage of eosinophils (EOS) were compared among the groups. RESULTS: Fifty-three patients who had undergone surgical treatment of hepatic HD and 55 healthy controls were included in the study. The mean follow-up time for all patients was 45 (14-70) months. The patients comprised 33 (62%) females and 20 (38%) males. The control group comprised 37 (67%) females and 18 (33%) males. The median age of the patients was 48 (19-78) years, while that of the control group was 42 (16-64) years. No significant differences in the HTC, PLT, or EOS were present among the groups. The MPV and PDW indicated that platelet function was significantly different between Group 1 and Groups 2 and 3. Additionally, nine patients had undergone previous surgical treatment for HD. In a separate long-term follow-up, these patients exhibited no statistically significant differences in MPV or PDW between the preoperative and postoperative periods. CONCLUSIONS: MPV and PDW can be used in the initial follow-up of patients with hepatic HD, but have limited use in long-term follow-up.

The effects of laparoscopic sleeve gastrectomy on head, neck, shoulder, low back and knee pain of female patients.

As the rise on the prevalence of obesity, it is related with physical impairment of joints, especially in the lumbar spine and knee joints. Losing body weight can reduce or eliminate pain of head, neck, shoulder, lumbar spine and knees. By performing a laparoscopic bariatric surgery we demonstrated a significant improvement on the pain by body weight reduction. In this study we aimed to explore the efficacy and safety of Laparoscopic Sleeve Gastrectomy (LSG) on the relief of pain on head and neck, shoulder, low back and knee among the severely morbid obese female patients. A total of 39 morbidly obese female patients who underwent LSG for morbid obesity were included in this study. Body weight, height, body mass index (BMI), head and neck, shoulder, low back and knee pain intensity were measured with Visual Analog Scale (VAS) before and after LSG at the 6(th) month. 39 morbidly obese female patients were enrolled to this study. The mean age of the patients was 37.69 ± 11.33 years. Preoperative and postoperative body weights were 127.3 kg and 91.21 kg, respectively. Mean height was 165.23 ± 5.78 cm. Preoperative and postoperative BMIs were 46.49 kg/m(2) and 32.33 kg/m(2), respectively. A significant correlation between preoperative and postoperative parameters was found according to BMI. Our data showed that LSG is an efficient and safe procedure on severely obese patients and showed a predictive remission of head and neck, shoulder, low back and knee pain intensity of female patients by analyzing with VAS during the first 6 months.

Protective effects of amifostine on ischemia-reperfusion injury of rat kidneys.

OBJECTIVES: Amifostine is a drug which can eliminate free oxygen radicals that appear in the body after radiation or chemotherapeutic agent exposure. It is used to decrease the renal toxicity of cisplatin. The aim of this study was to determine the role of amifostine in warm ischemia kidney model for prevention of ischemia/reperfusion injury and also to find out the mechanism for prevention from ischemia/reperfusion injury if such an effect does exist. MATERIALS AND METHODS: Adult female rats (n = 40) that used in our study were divided into three groups. Group 1: Control (n = 8), group 2: Ischemia-control (n = 16), group 3: Amifostine treated (n = 16). The effect of amifostine on ischemia/reperfusion injury investigated in rat kidneys. RESULTS: At the 7(th) day, blood urea nitrogen level was statistically significantly higher in ischemia-control group than all groups (P = 0.001) and mean serum creatinine levels were found to be the highest in ischemia-control group (P = 0.091). Mean malondialdehyde levels in left kidneys removed on the 7(th) day were not significantly different (P = 0.105) at all three groups. Between ischemia-control group and amifostine group, there was a significant difference in reduced glutathione (GSH) levels (P = 0.001). In amifostine group, grade 4 necrosis was not detected neither on 7(th) day nor day 0. CONCLUSION: Amifostine could decrease the degree and severity of necrosis after reperfusion. Amifostine could not prevent membrane lipid peroxidation caused by superoxide anion radicals in kidney but they could protect tissues from the harmful effects of ischemia/reperfusion injury by increasing the level of reduced GSH which is a well-known oxygen radical eliminator.

Life-threatening intrathyroidal parathyroid adenoma.

Acute primary hyperparathyroidism and parathyroid crisis are characterized by life-threatening hypercalcemia, a rare disorder. A 69-year-old female patient presented at our hospital's neurology clinic with weakness, nausea, vomiting, depression, and hypercalcemia. Treatment of hypercalcemia resulted in no improvement in neurological symptoms, indicating resistance to treatment. Thyroid ultrasonography and parathyroid scintigraphy revealed hypoechoic nodules in the right lobe, pieces of nodules in the left lobe, and high serum calcium and parathyroid hormone levels. After provision of intensive medical treatment including hydration, diuresis, and bisphosphonate infusion resulted in only minimal decrease in the calcium level, urgent surgical treatment was performed. Frozen biopsy of the right intrathyroidal giant parathyroid adenoma in the right lobe confirmed initial diagnosis of primary hyperparathyroidism. Based on the biopsy findings, right parathyroidectomy and right total and left subtotal thyroidectomy were performed. Histopathologic examination revealed a parathyroid adenoma localized inside large thyroid nodules. Review of the findings resulted in diagnosis of intrathyroidal parathyroid adenoma. Symptoms of hypercalcemia improved rapidly during the postoperative period.

Safety and effectiveness of three-port laparoscopic cholecystectomy.

UNLABELLED: Most commonly performed laparoscopic surgery is laparoscopic cholecystectomy. Although cholecystectomy through three port is not commonly preferred, researches have shown that it is a safe and feasible way of surgery. Material and Methods. We evaluate 100 patient that have undergone elective laparoscopic cholecystectomy through three port (group one). These patients were compared with 50 patients that have undergone laparoscopic cholecystectomy through four port (group two). Complications, lenght of stay in hospital, operation time, conversion to open surgery rate were compared in two group. RESULTS: In group one, fourth port was necessary for nine (9%) patients. Duration of operation in group one was in average 31 min and in group two, 31, 3 min. Operation time, lenght of stay in hospital, complication rate, conversion to open surgery rate was similar in both groups. CONCLUSION: Three port laparoscopic cholecystectomy is a safer method when performed by experienced surgeons. Laparoscopic cholecyctectomy can be tried through three ports firstly and can be continued with addition of fourth port if necessary.