Integrated Laparoscopic Management of Parastomal and Midline Incisional Double Hernias: A Staged Approach Including Hartmann's Reversal and Hernia Repair.

Parastomal hernia (PH) following Hartmann's procedure is a common late-term complication and is often combined with an incisional hernia (IH). The surgical treatment for double hernias with an end colostomy is complex and challenging. We present a 54-year-old woman with an end colostomy and combined hernias (PH and midline IH) after an emergency Hartmann's procedure for diverticular perforation of the sigmoid colon underwent staged surgery. First, laparoscopic Hartmann's reversal (LHR) and PH repair with primary suture were performed. Ten months later, "intraperitoneal onlay mesh repair (IPOM) plus" methods were implemented for IH repair. Both surgeries were successfully conducted using a laparoscopic approach, and no evidence of hernia recurrence has been observed in the 12 months after the second surgery. This case report provides valuable insights into the surgical strategy for double hernias with an end colostomy.

Impact of fundus-first laparoscopic cholecystectomy for severe cholecystitis.

BACKGROUND: The Tokyo Guidelines 2018 proposed fundus-first laparoscopic cholecystectomy (FFLC) as a bailout surgery. This study investigated the clinical impact of FFLC for severe cholecystitis. METHODS: This study reviewed 772 patients who underwent laparoscopic cholecystectomy (LC) between 2015 and 2018. Of these patients, 171 patients were diagnosed with severe cholecystitis according to our difficulty scoring system. FFLC was not prevalent in our faculty for the first 2 years [early period group (EG)], whereas FFLC was predominantly used for the last 2 years [late period group (LG)]. There were 81 patients (47%) belonging to the EG and 90 patients (53%) in the LG. The clinical data and the surgical outcomes of these patients were retrospectively analyzed. RESULTS: The difficulty score did not differ between the two groups (11 vs. 11 points, p = 0.846). Patients underwent FFLC significantly more frequently in the LG (63% vs. 12%, p = 0.020). Laparoscopic subtotal cholecystectomy (LSC) was done in 10 patients (11%) of the LG, which was significantly low compared to that in the EG (n = 20, 25%) (p = 0.020). In all patients, LC was safely achieved without bile duct injury or conversion to laparotomy. The incidence of choledocholithiasis was significantly low in the LG (0 vs. 4, p = 0.048). The median postoperative hospital stay was significantly shorter in the LG (6 vs. 4 days, p < 0.001). CONCLUSION: After the introduction of FFLC, there were significant improvements in the surgical outcomes of LC for severe cholecystitis, including the rate of LSC, incidence of choledocholithiasis, and duration of postoperative hospital stay.

Prognostic factors for the successful conservative management of nonocclusive mesenteric ischemia.

BACKGROUND: The criteria for deciding upon non-operative management for nonocclusive mesenteric ischemia (NOMI) are poorly defined. The aim of this study is to determine the prognostic factors for survival in conservative treatment of NOMI. METHODS: Patients with bowel ischemia were identified by searching for "ICD-10 code K550" in the Diagnosis Procedure Combination database between June 2015 and May 2020. A total of 457 patients were extracted and their medical records, including the clinical factors, imaging findings and outcomes, were analyzed retrospectively. Diagnosis of NOMI was confirmed by the presence of specific findings in contrast-enhanced multidetector-row CT. Twenty-six patients with conservative therapy for NOMI, including four cases of explorative laparotomy or laparoscopy, were enrolled. RESULTS: Among the 26 cases without surgical intervention, eight patients (31%) survived to discharge. The level of albumin was significantly higher, and the levels of lactate dehydrogenase, total bilirubin, C-reactive protein, and lactate were significantly lower in the survivors than the non-survivors. Sepsis-related Organ Failure Assessment (SOFA) score was significantly lower in the survivors than the non-survivors. The most reliable predictor of survival for NOMI was SOFA score (cutoff value ≤ 3 points), which had the highest AUC value (0.899) with odds ratio of 0.075 (CI: 0.0096-0.58). CONCLUSIONS: The SOFA score and several biological markers are promising predictors to determine a treatment plan for NOMI and to avoid unnecessary laparotomy.

Current status and future perspectives of robotic inguinal hernia repair.

With more than 5500 da Vinci Surgical System (DVSS) installed worldwide, the robotic approach for general surgery, including for inguinal hernia repair, is gaining popularity in the USA. However, in many countries outside the USA, robotic surgery is performed at only a few advanced institutions; therefore, its advantages over the open or laparoscopic approaches for inguinal hernia repair are unclear. Several retrospective studies have demonstrated the safety and feasibility of robotic inguinal hernia repair, but there is still no firm evidence to support the superiority of robotic surgery for this procedure or its long-term clinical outcomes. Robotic surgery has the potential to overcome the disadvantages of conventional laparoscopic surgery through appropriate utilization of technological advantages, such as wristed instruments, tremor filtering, and high-resolution 3D images. The potential benefits of robotic inguinal hernia repair are lower rates of complications or recurrence than open and laparoscopic surgery, with less postoperative pain, and a rapid learning curve for surgeons. In this review, we summarize the current status and future prospects of robotic inguinal hernia repair and discuss the issues associated with this procedure.

Laparoscopic Hartmann's reversal combined with interval lymphadenectomy after emergency surgery for perforated colon cancer: A case report.

A 55-year-old man underwent Hartmann's procedure for generalized peritonitis caused by perforation of sigmoid colon cancer, which was histologically diagnosed as tubular adenocarcinoma penetrating the muscularis propria (T3). The extent of lymph node dissection was insufficient for the advanced cancer, according to the concept of complete mesocolic excision. Two months after surgery, he underwent laparoscopic Hartmann's reversal, combined with interval lymphadenectomy. En bloc resection of the colostomy, rectal stump and associated mesentery was performed with high ligation of the inferior mesenteric artery. Subsequently, the intestinal continuity was restored by end-to-end anastomosis. The postoperative course was uneventful except for infection at the stoma site. No lymph node metastasis was found by histological examination of the resected specimen, with no evidence of cancer recurrence 8 months after the initial surgery.

Which is the best predictor of clinically relevant pancreatic fistula after pancreatectomy: drain fluid concentration or total amount of amylase?

AIM: Drain fluid amylase concentration (DFAC) has been reported as a predictor of clinically relevant postoperative pancreatic fistula (CR-POPF) after pancreatectomy. However, the clinical significance of measuring the total drain fluid amylase amount (DFAA) considering the daily drainage volume of CR-POPF remains unclear. METHODS: Data from 216 consecutive patients who underwent pancreaticoduodenectomy (PD) (n = 126) or distal pancreatectomy (DP) (n = 90) between August 2014 and November 2020 were reviewed. All drains were closed but not suctioned. DFAA was calculated by multiplying the DFAC and daily drainage fluid volume. DFAC and DFAA were recorded on d 1 and 3 after pancreatectomy. The cutoff value of CR-POPF was determined using the receiver operating characteristic curve. RESULTS: CR-POPF was found in 75 patients (35%) (PD: 30%, DP: 41%, P = .111); the mortality rate was zero. The cutoff value of DFAC-day 1 was 1757 U/L (sensitivity [SE]: 84%, specificity [SP]: 62%, and accuracy [AC]: 69%). The cutoff value of DFAA-day 1 was 139 U (SE: 71%, SP: 72%, and AC: 71%). The cutoff value of DFAC-day 3 was 1044 U/L (SE: 73%, SP: 79%, and AC: 78%). The cutoff value of DFAA-day 3 was 21 U (SE: 68%, SP: 72%, and AC: 70%). Multivariate analysis indicated that a nondilated pancreatic duct and high DFAC-day 3 were independently associated with CR-POPF after PD, indicating that a prolonged operative duration, massive blood loss, and high DFAC-day 3 are independently associated with CR-POPF after DP. CONCLUSION: DFAC is more reliable than DFAA for predicting CR-POPF after both PD and DP.

A case of resected hepatocellular carcinoma with gallbladder metastasis.

BACKGROUND: Advanced hepatocellular carcinoma (HCC) can often spread as intrahepatic metastases. Extrahepatic metastasis (e.g., lung, lymph nodes, and bones) is rare, and gallbladder metastasis from HCC is extremely rare. CASE PRESENTATION: A 66-year-old woman who presented with right hypochondrial pain was referred to our hospital for further examination of a liver tumor. The blood chemistry data showed elevated levels of serum α-fetoprotein (AFP) (3730 ng/mL), protein induced by vitamin K absence or antagonist II (PIVKA-II) (130 mAU/mL), and carcinoembryonic antigen (CEA) (358.6 ng/mL). Hepatitis B surface antigen and hepatitis C virus antibody were negative. Dynamic computed tomography (CT) showed a tumor measuring 12 × 7 cm in the right lobe of the liver. This tumor was contrast-enhanced in the hepatic arterial phase and then became less dense than the liver parenchyma in the portal phase. A well-enhanced tumor was found in the gallbladder. No regional lymph nodes were enlarged. Contrast-enhanced magnetic resonance imaging (MRI) demonstrated that the liver tumor showed a pattern of early enhancement and washout. The gallbladder tumor was also detected as an enhanced mass. Endoscopic retrograde cholangiography (ERC) showed compression of the left hepatic duct due to the liver tumor. The patient was diagnosed with simultaneous HCC and gallbladder cancer. Right hepatic trisectionectomy and caudate lobectomy with extrahepatic bile duct resection were performed. Histopathological examination of the resected liver specimen showed a poorly differentiated HCC cell component with a trabecular and solid growth, and diffuse invasion of the portal vein. The same tumor cells were found in the gallbladder, but no continuity with the liver tumor was identified. Immunohistochemistry of the liver tumor and gallbladder was positive for AFP, Glypican 3, and CK7, and negative for CK19. The final pathological diagnosis was the gallbladder metastasis from HCC. A follow-up diagnostic image 33 months after surgery showed a mass in the upper lobe of the left lung. The patient underwent left upper lobectomy. Postoperative pathology revealed that the lung lesion was a metastasis of HCC. The patient was still alive with lung metastasis and was being treated with a molecular-targeting drug in good health 42 months after the initial surgery. CONCLUSIONS: The standard treatment for advanced HCC with extrahepatic metastases is molecularly targeted drugs, but surgery is also an option if the lesion can be resected en bloc without remnants.

Calcium bilirubinate sludge causes early onset of congenital biliary dilatation: a report of two cases.

BACKGROUND: Symptomatic congenital biliary dilatation (CBD) during early infancy is always characterized by cystic dilation of the common bile duct with a narrow segment connecting the pancreatic duct. CASE PRESENTATION: In two consecutive infants with a prenatal diagnosis of CBD, we found that biliary sludge had formed in the cyst upon the appearance of symptoms including acholic stool and hypertransaminasemia. Infrared absorption spectrometry revealed that the sludge consisted of calcium bilirubinate. CONCLUSION: We suggest that overproduction of bilirubin by neonatal hemolysis causes sedimentation of bilirubin calcium, resulting in obstruction of the narrow segment and development of symptoms.

Ruptured intra-abdominal testicular seminoma with hemorrhage shock, after inadequate surgical exploration for undescended testis: a case report.

BACKGROUND: Undescended testes are associated with an increased risk of malignancy and infertility, and surgical treatment in childhood is recommended. CASE PRESENTATION: A 35-year-old man presented to the emergency department with abdominal pain and vomiting. Despite a history of surgery for a left undescended testis in infancy, his left-sided scrotum appeared underdeveloped. Contrast-enhanced computed tomography showed a pelvic mass, involving a major axis of approximately 15 cm, with high-density ascites suggestive of hemorrhage. A ruptured gastrointestinal stromal tumor was suspected. As he was in hemorrhagic shock, an emergency laparotomy was indicated. The active bleeding mass was controlled through complete resection. A pathological evaluation of the mass revealed a seminoma arising from an undescended testis. His post-operative course was uneventful, and he was discharged on post-operative day 6. Recurrence on the retroperitoneal lymph nodes was detected 1 year postoperatively, and a retroperitoneal lymph node dissection was performed after chemotherapy. He remains well without any apparent signs of recurrence. CONCLUSIONS: Paying close attention to an empty scrotum is advisable, even postoperatively, for undescended testis because of possible subsequent potential malignancy presenting with hemorrhage, as our patient demonstrated.

Preoperative Controlling Nutritional Status plus Tumor Burden Score for the Assessment of Prognosis after Curative Liver Resection for Hepatocellular Carcinoma.

OBJECTIVE: There are no previous studies analyzing the prognostic predictive value of adding the tumor factor (i.e., Tumor Burden (TB) score) to the Controlling Nutritional Status (CONUT) score for patients with hepatocellular carcinoma (HCC). This study aimed to investigate the value of the CONUT plus TB (CONUT-TB) score as a prognostic predictor in patients with HCC undergoing liver resection. METHODS: Between 2015 and 2018, 96 consecutive patients with HCC underwent liver resection at our institution. Patients undergoing repeated liver resection and combined resection of a metastatic lesion were excluded. Patients were divided into 2 groups according to their CONUT-TB scores according to a cutoff value. Clinicopathologic prognostic factors for survival were analyzed using a database containing the medical records. RESULTS: The optimal cutoff value of the CONUT-TB score determined by using a minimum p value approach was 13 points. Among the 81 patients included in the analytic cohort, 71 patients had low (<13) and 10 patients had high (>13) CONUT-TB scores. The overall 3-year survival rate of patients following liver resection for HCC in the high-CONUT-TB group was significantly worse than that of patients in the low-CONUT-TB group (62.5 vs. 89.3%, p = 0.003). Multivariate analysis indicated that a high CONUT-TB score was independently associated with overall survival after liver resection (p = 0.010). CONCLUSION: The CONUT-TB score is a valuable predictor of survival in patients with HCC after liver resection.

Dual common bile duct examination with transcystic choledochoscopy and cholangiography in laparoscopic cholecystectomy for suspected choledocholithiasis: a prospective study.

BACKGROUND: Detection of common bile duct (CBD) stones is a major objective of intraoperative cholangiography (IOC) in laparoscopic cholecystectomy (LC). We evaluated the feasibility and safety of the routine use of transcystic choledochoscopy following IOC (dual common bile duct examination: DCBDE), which may improve the diagnostic accuracy of CBD stones and facilitate one-stage clearance, in LC for suspected choledocholithiasis. METHODS: Between May 2017 and November 2018, 38 patients with suspected choledocholithiasis were prospectively enrolled in this study, regardless of whether they underwent endoscopic sphincterotomy. Transcystic choledochoscopy was routinely attempted following IOC in LC. RESULTS: Five cases were excluded due to cholecystitis, bile duct anomaly, or liver cirrhosis. DCBDE was performed in the remaining 33 patients. The biliary tree was delineated by IOC in all patients. Subsequently, choledochosope was performed in 32 patients except for one who was found to have pancreaticobiliary malunion in IOC. The scope was successfully passed into the CBD in 25 (78.1%) patients. Choledochoscopy detected 3 (9.4%) cases of cystic duct stones and 4 (12.5%) cases of CBD stones which were not identified by IOC. All those stones were removed via cystic duct. There were no intra- and postoperative complications, except for two cases of wound infection and one case of a transient increase in serum amylase. CONCLUSIONS: DCBDE in LC is a safe and promising approach for intraoperative diagnosis and one-stage treatment of suspected choledocholithasis.

A novel Killian-Jamieson diverticulectomy using a thyroid gland flap: a case report.

BACKGROUND: A Killian-Jamieson diverticulum is a rare pharyngoesophageal diverticulum that is radically treated by diverticulectomy. However, there is no consensus on whether cricopharyngeal myotomy is necessary, and the optimal surgical methods that prevent postoperative complications such as leakage are undetermined. CASE PRESENTATION: A 49-year-old man was referred to our hospital with oropharyngeal dysphagia while eating. The patient was preoperatively diagnosed with a Killian-Jamieson diverticulum based on radiographic and clinical findings and underwent a transcervical diverticulectomy. The recurrent laryngeal nerves were preserved using an intraoperative nerve monitoring system, and the diverticulum was identified without difficulty. A partial cricopharyngeal myotomy was performed to expose the base of the diverticulum. The diverticulum was transected transversally using a linear stapler under the guidance of intraoperative upper intestinal endoscopy. A thyroid gland flap supplied by the superior thyroid artery was harvested and placed overlapping the area of the partial cricopharyngeal myotomy. Due to the proximity of the recurrent laryngeal nerve course to the diverticulum stump, the staple line was not buried with sutures. The thyroid gland flap with its rich vascular supply was fixed to completely cover the staple line on the cut surface of the thyroid gland. The postoperative course was uneventful, without vocal cord paralysis. The patient was discharged on postoperative day 8. He developed no clinical signs suggesting leakage, recurrence, or adverse events. CONCLUSION: Killian-Jamieson diverticulectomy using a thyroid gland flap and partial cricopharyngeal myotomy is a valid treatment option that may prevent complications and recurrence. Precise evaluation of the diverticulum using an intraoperative nerve monitoring system is crucial for the repair.

Preliminary results of robotic inguinal hernia repair following its introduction in a single-center trial.

AIM: Robotic surgery using the da Vinci system has markedly increased worldwide. However, robotic inguinal hernia repair remains unpopular outside the United States. We introduced and evaluated a robotic transabdominal preperitoneal repair (R-TAPP) technique for inguinal hernia in our hospital. METHODS: First, we designed a task protocol according to the surgical results of 388 laparoscopic TAPP (L-TAPP) procedures performed during the 4 years prior to introducing R-TAPP. Our task protocol included several time limitations during a step-wise procedure: creating the peritoneal flap (<60 minutes), mesh placement with fixation (<30 minutes), and peritoneal suture closure (<30 minutes) under experienced supervision. We investigated the preliminary clinical results of R-TAPP performed by a single operator between December 2018 and January 2020. RESULTS: We identified 27 lesions in 20 patients (unilateral in 13 and bilateral in seven). According to the Japan Hernia Society Classification, our cohort included eight type I, five type II, and seven bilateral hernias (nine type I, four type II, and one type IV). The median operation time was 124 minutes (range, 81-164 minutes), and the median console operation time was 85 minutes (range, 50-132). The median time required for the peritoneal incision was 30 minutes (range, 18-54 minutes), that for mesh placement (including tucking) was 13 minutes (range, 7-27 minutes), and that for peritoneal suturing was 9 minutes (range, 3-20 minutes). CONCLUSION: Our preliminary results suggest that our task protocol for R-TAPP is feasible. However, refinement of our task protocol is essential for standardization.

A novel classification of aberrant right hepatic ducts ensures a critical view of safety in laparoscopic cholecystectomy.

BACKGROUND: Based on the spatial relationship of an aberrant right hepatic duct (ARHD) with the cystic duct and gallbladder neck, we propose a practical classification to evaluate the specific form predisposing to injury in laparoscopic cholecystectomy (LC). METHODS: We retrospectively investigated the preoperative images (mostly magnetic resonance cholangiopancreatography) and clinical outcomes of 721 consecutive patients who underwent LC at our institute from 2015 to 2018. We defined the high-risk ARHD as follows: Type A: communicating with the cystic duct and Type B: running along the gallbladder neck or adjacent to the infundibulum (the minimal distance from the ARHD < 5 mm), regardless of the confluence pattern in the biliary tree. Other ARHDs were considered to be of low risk. RESULTS: A high-risk ARHD was identified in 16 cases (2.2%): four (0.6%) with Type A anatomy and 12 (1.7%) with Type B. The remaining ARHD cases (n = 34, 4.7%) were categorized as low risk. There were no significant differences in the operative outcomes (operative time, blood loss, hospital stay) between the high- and low- risk groups. Subtotal cholecystectomy was applied in four cases (25%) in the high-risk group, a significantly higher percentage than the low-risk group (n = 1, 2.9%). In all patients with high-risk ARHD, LC was completed safely without bile duct injury or conversion to laparotomy. CONCLUSIONS: Our simple classification of high-risk ARHD can highlight the variants located close to the dissecting site to achieve a critical view of safety and may contribute to avoiding inadvertent damage of an ARHD in LC.

Novel approach to intraoperative peritoneal lavage with an extracorporeal stirring method in laparoscopic surgery for generalized peritonitis: Preliminary results.

INTRODUCTION: The primary concern with laparoscopic intraoperative peritoneal lavage (IOPL) for generalized peritonitis relates to the difficulty and uncertainty in ensuring adequate washout of contaminated fluid. Here, we describe a new method of laparoscopy-assisted IOPL. METHODS: We performed emergency surgery in 10 patients with generalized peritonitis necessitating IOPL. A small wound retractor was inserted into the abdominal cavity through an incision and elevated to raise the abdominal wall. More than 3-L saline was injected via the retractor at one time. The abdomen was manually shaken by pressure from outside the body. Contaminated fluid was removed with a long suction device through the retractor. This procedure was repeated until the fluid was confirmed to be transparent by laparoscopy, and then drains were placed. RESULTS: Median lavage time was 23.5 minutes (range, 15-34 minutes), and volume of lavage fluid was 19 L (range, 10-20 L). Median time to resumption of fluid intake was 3 days (range, 1-12 days), time to food intake was 6 days (range, 3-14 days), and time to first bowel movement was 5 days (range, 3-10 days). Median duration of antibiotic use was 8.5 days (range, 5-15 days). Complications were one case of antibiotic-induced rash, two cases of paralytic ileus, and one case of pelvic abscess. All patients recovered well without additional surgical intervention. CONCLUSIONS: This new approach to laparoscopy-assisted IOPL was feasible for these patients with generalized peritonitis. This procedure enabled corpus lavage to be performed in a similarly short time to open surgery but with less invasiveness. Further research is needed to confirm indications and long-term outcomes.

Laparoscopic repair of secondary perineal hernia with coverage by the mobilized cecum.

The incidence of secondary perineal hernia (SPH) has increased since the introduction of extralevator abdominoperineal resection and laparoscopic abdominoperineal resection. Currently, laparoscopic mesh repair is the usual procedure. Here, we demonstrate a repair of SPH without mesh that uses the mobilized cecum to cover the pelvic hernial orifice. An 83-year-old man complained of discomfort when sitting for long periods. He was status post laparoscopic abdominoperineal resection and was diagnosed with SPH. Hernia repair was performed. After transperitoneal adhesiolysis in the inferior pelvis, the right colon was laparoscopically mobilized, and the pelvic orifice was covered by suturing the cecum to the pelvic brim. The perineal skin was managed with negative pressure wound therapy. The postoperative course was uneventful. There has been no sign of recurrent herniation for 12 months. This method of SPH repair is simple to perform and avoids mesh-related complications.

Closure of the cystic duct orifice in laparoscopic subtotal cholecystectomy for severe cholecystitis.

INTRODUCTION: Laparoscopic subtotal cholecystectomy (LSC) has been recognized as an alternative to conversion to laparotomy for severe cholecystitis. However, it may be associated with an increased risk of recurrent stones in the gallbladder remnant. The objective of this study was to evaluate the safety and feasibility of the complete removal of the gallbladder cavity in LSC for severe cholecystitis using the cystic duct orifice suturing (CDOS) technique. METHODS: In a consecutive series of 412 laparoscopic cholecystectomies that were performed from January 2015 to June 2017, 12 patients who underwent LSC with CDOS were enrolled in this retrospective study. In this procedure, Hartmann's pouch was carefully identified, and the infundibulum-cystic duct junction was transected while the posterior wall adherent to Calot's triangle was left behind. The clinical records, including the operative records and outcomes, were analyzed. RESULTS: The median operating time and blood loss were 158 min and 20 mL, respectively. In all cases, LSC with CDOS was completed without conversion to open surgery. No injuries to the bile duct or vessels were experienced. The median postoperative hospital stay was 6 days. Postoperative complications occurred in two patients (bile leakage, n = 1: common bile duct stones, n = 1) and were successfully treated by endoscopic management. A gallbladder remnant was not delineated by postoperative imaging in any of the cases. CONCLUSION: These results suggest that LSC with CDOS is a promising approach that can avoid dissection of Calot's triangle and achieve the complete removal of the gallbladder cavity in patients with severe cholecystitis.

[A Case of Local Recurrence and Lung Metastasis from a Rectal Cancer Treated with Systemic Chemotherapy and Cyberknife].

A 73-year-old man underwent abdominoperineal resection for a rectal cancer. He developed a hip pain 3 years and 6 months after the surgery. A CT scan revealed a local recurrence in the perineum and multiple lung metastases in the bilateral lung. He received systemic chemotherapy consisting of XELOX with bevacizumab. Thereafter, the hip pain was slightly relieved. The hip pain worsened 1 year and 6 months after the recurrence. The border between the perineal tumor and skin was very narrow, and conventional radiation therapy could cause a perineal skin necrosis and subsequent poor wound healing. Therefore, we selected a Cyberknife treatment. The hip pain was relieved and a CT scan showed a reduction of the perineal tumor's size after the Cyberknife treatment. A Cyberknife treatment may be effective and promising as palliation for patients with local recurrence of rectal cancer.

Phase-shifting color digital holography.

Digital holography with a three-wavelength laser and a color CCD has been demonstrated. With the phase shifting of the reference beam, in-line holograms for three wavelengths are recorded simultaneously for derivation of the complex amplitude at each wavelength, and then the three monochromatic images are reconstructed and combined into full-color images in the computer. Laser power variation for wavelengths can be compensated for in the reconstruction process. We have compared the images reconstructed by two algorithms using a single Fourier transformation and a convolution with each other by both experiments and numerical simulations. Phase-shifting errors arising at two of the three wavelengths have proved not to cause serious deterioration of the reconstructed images.

Multicolor digital holography with an achromatic phase shifter.

Multiwavelength recording and reconstruction of a three-dimensional object are realized by use of phase-shifting digital holography. Red, green, and blue lines emitted from a white-light He-Cd laser are used for one-step recording of the complex amplitude of the object with a color CCD camera, in which a phase shift is introduced with an achromatic phase shifter based on the geometric phase. Three color images are reconstructed and successfully combined in a computer by use of Fresnel transformation based on a convolution.